Archive | review

First Look – Arduino M0 Pro with 32 bit ARM Cortex M0

Here at tronixstuff we keep an open mind with regards to new hardware, and in this spirit we have the following “first look” of the new Arduino M0 Pro (previously called the Arduino Zero) from Arduino SRL. If the term Arduino SRL is new to you – click here to learn more.

Arduino M0 Pro from Tronixlabs Australia 1

This is the second Arduino-branded board that takes the leap from 8-bit to 32-bit microcontrollers (with the Due being the first), and according to Arduino SRL offers a lot of promise:

With the new Arduino M0 pro board, the more creative individual will have the potential to create one’s most imaginative and new ideas for IoT devices, wearable technologies, high tech automation, wild robotics and other not yet thinkable adventures in the world of makers.

The Arduino M0 pro represents a simple, yet powerful, 32-bit extension of the Arduino UNO platform. The board is powered by Atmel’s SAMD21 MCU, featuring a 32-bit ARM Cortex® M0 core.

With the addition of the M0 board, the Arduino family becomes larger with a new member providing increased performance.

The power of its Atmel’s core gives this board an upgraded flexibility and boosts the scope of projects one can think of and make; moreover, it makes the M0 Pro the ideal educational tool for learning about 32-bit application development.
Atmel’s Embedded Debugger (EDBG), integrated in the board, provides a full debug interface with no need for additional hardware, making debugging much easier. EDBG additionally supports a virtual COM port for device programming and traditional Arduino boot loader functionality uses.

Lots of buzzwords in there, so let’s push that aside and first consider the specifications:

Microcontroller – ATSAMD21G18, 48pins LQFP – the “main” microcontroller
EDBG Microcontroller – AT32UC3A4256, 100pins VFBGA
Operating Voltage – 3.3 V
DC Input Voltage (recommended) – 6-15 V
DC Input Voltage (limits) – 4.5-20 V
Digital I/O Pins – 14, with 12 PWM and UART
Analogue Input Pins – 6, 12-bit ADC channels
Analogue Output Pins – 1, 10-bit DAC
DC Current per I/O Pin – 7 mA
Flash Memory – 256 KB
SRAM – 32 KB
Clock Speed – 48 MHz

Lots of good stuff there – increased clock speed, increased flash memory (sketch space) and SRAM (working memory). No EEPROM however you can emulate one.

Note that the M0 Pro is a 3.3V board – and also the DC current per I/O pin is only 7 mA. Once again the user will need to carefully consider their use of external circuitry and shields to ensure compatibility (as the “classic” Arduino boards are 5V and can happily source/sink much more current per I/O pin).

The ADC (analogue-to-digital) converters have an increased resolution – 12-bit… and the addition of a true DAC (digital-to-analogue) converter allows for a true variable voltage output. This could be useful for sound generation or other effects. You can pore over the complete details including board schematics from the arduino.org website.

Moving on, let’s have a look around the Arduino M0 Pro board itself:

Arduino M0 Pro from Tronixlabs Australia 1

You can’t miss the sticker asking you to download the IDE – as Arduino SRL have forked up the Arduino IDE and run off with it. Click here to download. Upon removing the sticker you have:

Arduino M0 Pro from Tronixlabs Australia

Note the connector for the JTAG interface which works in conjunction with Atmel Studio software for debugging. You can also use the USB connection which connects to the EDBG microcontroller (example). When Atmel offers a native MacOS version we’ll investigate that further. SPI isn’t D10~D13 as per the older boards, instead it is accessed via the six pins on the right-hand side of the board. Turning the M0 Pro over doesn’t reveal any surprises:

Arduino M0 Pro from Tronixlabs Australia 1

And like the Due there are two USB ports:

Arduino M0 Pro from Tronixlabs Australia 1

A Programming USB port for uploading sketches through the Arduino IDE and “normal” use, along with a native USB port for direct connection to the main microcontroller’s serial connection. For “regular” Arduino IDE use, you can stick with the Programming port as usual.

So let’s try out the M0 Pro. We’ve downloaded the arduino.org IDE (which can co-exist with the arduino.cc IDE). Drivers are included with the IDE for Windows users, so the board should be plug and play. Note that if you need to reflash the Arduino bootloader – Atmel Studio is required. Moving on – within the Arduino IDE you need to set the board type to “Arduino M0 Pro (Programming Port)”:

Arduino M0 Pro from Tronixlabs Australia IDE 1

… and the Programmer to “M0 Pro Programming Port”:

Arduino M0 Pro from Tronixlabs Australia port 1

… both of these options are found in the Tools menu. When using these faster boards we like to run a simple speed test that calculates Newton Approximation for pi using an infinite series, written by Steve Curd from the Arduino forum. You can download the sketch to try yourself.

In previous tests the Arduino Mega2560 completed the test in 5765 ms, and the Arduino Due crushed it in 690 ms. As you can see below the M0 Pro needed 1950 ms for the test:

Arduino M0 Pro from Tronixlabs Australia speed

Not bad at all compared to a Mega. Thus the M0 Pro offers you a neat speed bump in an Uno-compatible form-factor. At this point those of you who enjoy making your own boards and dealing with surface-mount components have an advantage – the Atmel ATSAMD21G18 is available in TQFP package for under US$6… so you could cook up your own high-performance boards. Example.

At this point I’m curious about the onboard 10-bit DAC that’s connected to pin A0, so I connected the DSO to A0 and GND, and uploaded the following sketch:

… which resulted with the following neat triangle waveform:

Arduino M0 Pro DAC fast

… and here it is with the statistics option:

Arduino M0 Pro DAC fast stats

With a frequency of 108.7 Hz there’s a lot of CPU overhead – no doubt controlling the MCU without the Arduino abstraction will result with increased performance. Finally – for some other interesting examples and “how to” guides for the M0 Pro, visit the Arduino labs page for this board.

Conclusion for now

There are many pros and cons with the Arduino M0 Pro. It is not the best “all round” or beginner’s board due to the limitations of the hardware GPIO. There’s the DAC which could be useful for creating Arduino-controlled power supplies – and plenty of PWM outputs… but don’t directly connect servos to them. However if you can live with the current limits – and need a faster clock speed with an Arduino Uno-compatible board type – then the M0 Pro is an option for you.

Furthermore the M0 Pro offers an interesting bridge into the world of 32-bit microcontrollers, and no doubt the true performance of the MCU can be unlocked by moving away from the Arduino IDE and using Atmel Studio. If you have any questions for the arduino.org team about the Arduino M0 Pro ask in their support forum.

Finally, check out tronixlabs.com – which along with being Australia’s #1 Adafruit distributor, also offers a growing range and great value for supported hobbyist electronics from Altronics, DFRobot, Freetronics, Jaycar, Seeedstudio and much much more.

visit tronixlabs.com

As always, have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

Posted in arduino, Arduino SRL, M0 Pro, review, tronixlabs, tronixstuff2 Comments

Review – Intel Galileo Arduino-compatible Development Board

Introduction

Over the last year or two the rise of the single-board computer has captured the imagination and energy of many people, to the point where popular opinion has been that the Arduino world had been left behind. However this is far from the truth – there’s Arduino-compatible SBCs such as the pcDuino and now we have one from Intel  – the Intel Galileo.

Intel Galileo box

Apparently the Galileo has been available in limited distribution for a few months, and now that the marketing machine has started up – we finally had the chance to order an Intel Galileo last week and now have one as the subject for this review. It’s our first look, based on information we could find at the time and some experimenting.

What’s in the box?

In the retail package we found the Intel Galileo itself:

Intel Galileo box inside

Intel Galileo

… a diagram of what to do in the lid:

Intel Galileo box inside lid

… and a universal AC to 5V 2A DC power supply with various fittings for different regions:

Intel Galileo power supply

The only paper documentation was a safety and regulatory information booklet which gets recycled. We didn’t find a USB cable nor some stand-offs to lift the board off the bench a little.

Specifications

The Galileo is based a new chipset from Intel, the Quark SoC X1000 Application Processor, a 32-bit Intel Pentium-class system on a chip. For the uninitiated, the Galileo is a single-board computer running a small version of Linux that can somewhat emulate an Arduino Uno R3 in software. The hardware specifications are as such (from the Arduino website):

  • 400MHz 32-bit Intel® Pentium instruction set architecture (ISA)-compatible processor o 16 KBytes on-die L1 cache
    • 512 KBytes of on-die embedded SRAM
    • Simple to program: Single thread, single core, constant speed
    • ACPI compatible CPU sleep states supported
    • An integrated Real Time Clock (RTC), with an optional 3V “coin cell” battery for operation between turn on cycles.
  • 10/100 Ethernet connector
  • Full PCI Express* mini-card slot, with PCIe 2.0 compliant features
    • Works with half mini-PCIe cards with optional converter plate
    • Provides USB 2.0 Host Port at mini-PCIe connector
  • USB 2.0 Host connector
    • Support up to 128 USB end point devices
  • USB Device connector, used for programming
    • Beyond just a programming port – a fully compliant USB 2.0 Device controller
  • 10-pin Standard JTAG header for debugging
  • Reboot button to reboot the processor
  • Reset button to reset the sketch and any attached shields
  • Storage options:
    • Default – 8 MByte Legacy SPI Flash main purpose is to store the firmware (or bootloader) and the latest sketch. Between 256KByte and 512KByte is dedicated for sketch storage. The download will happen automatically from the development PC, so no action is required unless there is an upgrade that is being added to the firmware.
    • Default 512 KByte embedded SRAM, enabled by the firmware by default. No action required to use this feature.
    • Default 256 MByte DRAM, enabled by the firmware by default.
    • Optional micro SD card offers up to 32GByte of storage
    • USB storage works with any USB 2.0 compatible drive
    • 11 KByte EEPROM can be programmed via the EEPROM library.

However unlike other SBCs on the market – you don’t get any video or audio output.

Let’s have a quick look around the board. Here you can see the DC socket and microSD card socket:

Intel Galileo DC end

 From the view below you can see the Arduino shield stacking headers and flash memory:

Intel Galileo ICSP end

… more jumpers for settings, a USB host socket, USB connection (client) socket, RS232 via 3.5mm socket (!) and 10/100 Ethernet:

Intel Galileo socket end

… and some nifty jumpers to select 3.3 or 5V operation for shields and IOREF:

Intel Galileo IOREF Vin jumpers

… this jumper pair is to add a 3V battery to keep the real-time clock ticking over when the main supply is removed:

Intel Galileo RTC battery jumpers

Perhaps a CR2032 button cell holder would be preferable, there’s plenty of room on the PCB. Finally – the two reset buttons:

Intel Galileo reset buttons

If you want to reset your emulated Arduino, press the one on the left (labelled I). If you want to reboot the entire computer, press the one on the right (labelled X). This seems a little counter-intuitive, as you would imagine the button closer to the stacking headers would reset the Arduino. Note that if you reboot the computer, the last sketch you’ve uploaded will be removed and need to be uploaded again. Furthermore, more often than not rebooting the Galileo wasn’t entirely successful – and required a full removal of USB, power then replacing the power and USB to get another connection.

Turning the Galileo over reveals some fascinating PCB track patterns, and the mini-PCIe connector:

Intel Galileo bottom 2

Getting Started

Having a slight bent towards Arduino, the first thing we like to do is get the blink sketch running. The documentation is scattered all over the place, so start from maker.intel.com and follow the links listed in the “Explore Intel makers” column. The closest thing to a quick setup guide can be downloaded hereThere’s a video by what sounds to be a ten year old explaining the board – who signs off by telling us it’s ok to break something (hopefully not the Galileo at $77 a pop). Marketing FTW. Eventually we found the official Intel support page for the Galileo, so bookmark that for future reference.

However if you just want to get started as quickly as possible, keep reading. First, download the Arduino IDE for Galileo from here. Next, extract the IDE folder to your root directory – and don’t have any spaces in the folder name. For example, use:

and not:

Now plug in your Galileo – and always plug the 5V power into the Galileo before the USB (use the “USB client” socket). For Windows the USB driver (for “Gadget Serial v2.4”) is in the IDE folder, just point Windows to the top Galileo Arduino IDE folder.

Note that it takes around twenty seconds for the PC to recognise the Galileo via USB (as the Galileo needs time to boot up – it’s running Linux). For Windows users – after loading the IDE, check which COM port has been allocated. For some reason the Galileo can’t deal with COM10 or higher. To change this, head over to the Device Manager. Open Ports (COM & LPT) then right-click the Galileo and click properties:

Intel Galileo Change COM number

Next, click the Port Settings tab, then Advanced:

Intel Galileo Change COM number tab

Then select a free COM port number that’s under 10, close all the dialogue boxes and restart the computer. After the reboot, load the IDE, select the right board and serial port in the Tools menu – then select Firmware Update in the Help Menu. If for some reason you put a memory card in the microSD card slot – remove it before this process.

Intel Galileo Windows Firware Update

A confirmation box will appear, so move forward and wait for the process to finish. Don’t touch the IDE, board or anything near the Galileo until this finishes. Read some kit reviews. The update process took eight minutes for us, however will depend on the speed of your Internet connection.

Intel Galileo Windows Firware Update status

Finally, try the ubiquitous blink sketch. Once uploaded,  the tiny LED next to the coin cell jumpers will blink as requested. Now we’ll explore more about using the Galileo as an Arduino-compatible board.

How Arduino-compatible is the Galileo?

The first thing we like to do with new boards that differ from the classic Uno is to run a speed test, and for this we use the following sketch by Steve Curd from the Arduino forum:

It calculates Newton Approximation for pi using an infinite series. For comparison an Arduino Due takes 690 ms, an Arduino Mega 2560 takes 5765 ms, and a pcDuino v2 can do it in 9 to 43 ms (depending on what else is running on Linux). So out of the box, the Galileo takes 279 ms:

Intel Galileo Arduino speed test

Out of the box there is 262144 bytes available for sketches. As the Arduino is emulated, the hardware for I/O is a little different than you may have expected, and provided by a variety of I2C port expanders, MUXs and so on. For example I2C can only run at 100 kHz in master mode, no slave mode, and similar restrictions on SPI as well. Again, review this page to learn more about the internal hardware differences between an Arduino Uno and Intel Galileo.

Visit this page and scroll down to the block diagram for a visual representation, and while you’re there – review the entire page to learn more about the specific Arduino Uno R3 implementation on the Galileo. A lot of work has been done to allow successful emulation of the Arduino using the Quark CPU and internal OS. For example the EEPROM library just works, and has 11264 bytes of storage.

You can get an idea of what is supported “out of the box” by reviewing the libraries included with the Galileo’s IDE installation, for example:

Intel Galileo Arduino IDE examples

So most of the basic requirements are covered at the time of writing. And unlike some other SBCs emulating Arduino, the onboard Ethernet “just works” as it should with the Ethernet library – and the USBHost library can take advantage of the matching socket on the board. Again – research is the key, so spend some time determining if the Galileo can solve your problems.

One interesting example of the limitations of the “emulated” Arduino is the speed, and this has been highlighted by Al Williams of Dr Dobb’s journal – who ran a simple sketch to see how fast a digital output pin could be set. As GPIO is provided by external SPI- and I2C-based interface ICs, there will be a speed hit. But how much? Naturally we can’t use port manipulation so we’re back to simple digitalWrite functions with the following sketch:

An Arduino Uno running the sketch was clocked at 96.34 kHz:

Arduino Uno digitalWrite test

… and the Intel Galileo was clocked at … 225.2 Hz:

Intel Galileo digitalWrite test

This test isn’t a criticism of the Galileo, just an example of what you need to keep in mind when using it. If you’re curious about the real-time clock it’s accessed via Linux. Finally, there’s a list of known issues on the Intel forum – so check this out to get a grip on what is and is not working in terms of Arduino compatibility. One more thing – you will need a memory card installed if you want the Galileo to remember sketches after power-off.

Update – thanks to our friends (!) at reddit, you can push some I/O faster – see this post in the Intel forum.

Linux – internal

The Galileo arrived pre-loaded with a very light version of Linux, however due to the lack of video output you need to access the “computer” via some old-school methods. And thus one method is via Telnet over Ethernet. If you don’t have a Telnet client, try PuTTY. To get started, ensure you have your Galileo connected to power, client USB to PCm and to your LAN. Then upload the following sketch to your Galileo:

The observant will notice by using the system function you can send instructions to the Linux command line from your Arduino sketch. And any resulting output text can be sent to the serial monitor by directing it to ttyGS0.

Anyhow, the above sketch will run the ifconfig command and return relevant networking data about your Galileo – including its IP address:

Intel Galileo telnet sketch

Once you have the IP address, you can Telnet in and command your Galileo just like it’s 1992:

Intel Galileo poky linux box telnet

Don’t get too excited, there isn’t that much installed (e.g. no gcc or make). For more information on the Poky linux, visit the project page. Apart from running vi my *nix memory is a bit vague, however the onboard system is quite minimal. If you want to do anything serious, such as use a WiFi or other PCIe card – you’ll need to boot your Galileo with an external OS stored on a microSD card. Another way of looking at the Galileo is that it’s a board not for development with, but for running code built on a different system and then loaded onto the Galileo.

Linux – external

As I haven’t been a *nix user for a very long time, it didn’t seem worthwhile to spend a whole day preparing for an installing the external OS on the Galileo for review. However from what I can tell you’ll need to do this to run anything substantial including WiFi adaptors, python, node.js and so on. Which in my personal opinion sort of ruins the Galileo for me. Other SBCs can do all of this a lot easier, cheaper and with better documentation.

Arduino Support

As the Galileo is from Intel and not Arduino, you need to ask for support in the Intel forum. This will be an interesting test for Intel, will they invest in a substantial support effort or just stand back and say it’s all open source? Time will tell. In the meanwhile there is a gallery hosted by Intel with links to different projects.

Conclusion

Once again – remember that the Galileo is a limited single-board computer that emulates (to a certain, varying degree) an Arduino Uno R3. It is a contender if you need to integrate some Arduino-based control with software running on a light Linux machine, and all in a compact board. Or if you want to experiment with USB host and Ethernet on the Arduino platform at the same time, this could be a cheaper and more powerful option. Support is there if you can use Google, however this is not the idea beginners’ Arduino board. So don’t be a sheep and rush out and buy one after reading the marketing blurb – do your own research first.

Personally I would say that if you have a need for the specific hardware interfaces of the Galileo, and have a full understanding of the board limitations – then it’s the board for you. Otherwise if you want to experiment with a full single-board computer with Arduino compatibility, get a pcDuino. Full-sized images are available on flickr.

And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop”.

visit tronixlabs.com

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

[Note – Intel Galileo purchased for review by tronixstuff.com and not a promotional consideration]

Posted in arduino, galileo, intel, review, tronixstuff, tutorial

Review – Iteaduino Lite “nearly 100% Arduino-compatible” board

Introduction

Over the last year there have been a few crowd-funded projects that offered very inexpensive Arduino-compatible boards. Frankly most of them weren’t anything out of the ordinary, however one of them is quite interesting due to the particular design of the board, and is the subject of this review.

An established company Iteadstudio ran a successful Indiegogo campaign last December to fund their Iteaduino Lite – Most inexpensive full-sized Arduino derivative board”. Having a spare US$5 we placed an order and patiently waited for the board. Being such a low price it was guaranteed to raise the funding – but was it worth the money? Or the effort? Possibly.

The board

In typical fashion the board arrived in bare packaging:

Iteaduino Lite arrived

 The Iteaduino Lite isn’t that surprising at first glance:

Iteaduino Lite bare top

To the new observer, it looks like an Arduino board of some sort. Nice to see all those GPIO pins with double breakouts. No surprises underneath:

Iteaduino Lite bottom

The URL on the bottom is incorrect, instead visit http://imall.iteadstudio.com/iteaduino-lite.html. Looking at the board in more detail, there are some interesting points of difference with the usual Arduino Uno and compatibles.

The USB interface is handled with the Silabs CP2102 USB to UART bridge IC:

Iteaduino Lite CP2102 USB

The next difference is the power circuitry – instead of using a linear voltage regulator, Itead have used a contemporary DC-DC converter circuit which can accept between 7 and 24V DC:

Iteaduino lite power supply

Furthermore, the entire board can operate at either 5V or 3.3V, which is selected with the slide switch in the above image. Finally – the microcontroller. Instead of an Atmel product, Itead have chosen the LogicGreen LGT8F88 microcontroller, a domestic Chinese product:

Iteaduino Lite LGT8F88A MCU

And there are only two LEDs on the Iteaduino Lite, for power and D13. The LED on D13 ins’t controlled via a MOSFET like other Arduino-compatibles, instead it’s simply connected to GND via a 1kΩ resistor.

Getting started with the Iteaduino Lite

The stacking header sockets will need to be soldered in – the easiest way is to insert them into the board, use an shield to hold them in and flip the lot upside down:

Iteaduino lite stacking headers

Which should give you neatly-installed headers:

Iteaduino Lite ready to use

Watch out for the corners of the board, they’re quite sharp. Next, you need to install the USB driver for the CP2102. My Windows 7 machine picked it up without any issues, however the drivers can be downloaded if necessary.

Finally a new board profile is required for the Arduino IDE. At the time of writing you’ll need Arduino IDE v1.0.5 r2. Download this zip file, and extract the contents into your ..\Arduino-1.0.5-r2\hardware folder. The option should now be available in the Tools > Board menu in the IDE, for example:

Iteaduino Lite Arduino IDE

From this point you can run the blink example to check all is well. At this point you will realise one of the limitations of the Iteaduino Lite – memory. For example:

Iteaduino Lite Arduino IDE memory

You only have 7168 bytes of memory for your sketches – compared to 32, 256 for an Arduino Uno or compatible. The reason for this is the small capacity of  …

The LogicGreen LGT8F88 microcontroller

This MCU is a Chinese company’s answer to the Atmel ATmega88A. You can find more details here, and Itead also sells them separately. The LGT8F88 offers us 8Kbyte of flash memory of which 0.7KB is used by bootloader, 1 KB of SRAM and 504 bytes (count ’em) of EEPROM. Apparently it can run at speeds of up to 32 MHz, however the LGT8F88 is set to 16 MHz for the Iteaduino Lite.

According to Logic Green, their LGT8F88 “introduce a smart instruction cache, which can fetch more instructions one time, effectively decrease memory accessing operations“. So to see if there’s a speed bump, we uploaded the following sketch – written by Steve Curd from the Arduino forum. It calculates Newton Approximation for pi using an infinite series:

For a baseline comparison, an Arduno Uno R3 completes the calculations in 5563 ms:

Iteaduino Lite Uno speed test

… and the Iteaduino Lite completed it in 5052 ms:

Iteaduino Lite speed test

So that’s around a 10% speed increase. Not bad at all. The LGT8F88 also has the requisite GPIO, SPI, and I2C available as per normal Arduino Uno boards. You can download the data sheet with more technical details from here. Frankly the LGT8F88 is an interesting contender in the marketplace, and if Logic Green can offer a DIP version at a good price, the ATtiny fans will have a field day. Time will tell.

Power Circuit

The DC-DC circuit promises 5V output, with up to 24V DC input – so we cranked the input to 24V,  put a 1A load on the 5V output – and put the DSO over 5V to measure the variations – with a neat result:

Iteaduino lite PSU test

So no surprises there at all, the Iteaduino Lite gives you more flexible power supply options than the usual Arduino board. However an eagle-eyed reader notes that a few of the capacitors are only rated at 25V – especially the two right after the DC socket/Vin. You can see this in the schematic (.pdf). So take that into account, or drop your Vin to something more regular such as below 12V.

Conclusion

The Iteaduino Lite is an interesting experiment in bargain Arduino-compatible boards. However we say “why bother?” and just get a Uno R3-compatible board.

At the end of the day – why bother with this board? For a little extra you can get boards with the ATmega328P or 32U4 which gives you 100% compatibility. Nevertheless, this was an interesting experiment. Full-sized images are available on flickr. And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop”.

visit tronixlabs.com

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, iteaduino, LGT8F88, review, tronixstuff0 Comments

Review – NXP LPC800-MAX Development Board

Introduction

Now and again we examine various development boards designed for use with the mbed development platform for ARM microcontrollers, such as the the original mbed unit and the Freescale Freedom FRDM-KL25Z – and now we have another one from NXP … their new LPC800-MAX development board:

LPC800-MAX front PCB

LPC800-MAX rear PCB

Although the LPC800-MAX works with the mbed online compiler, you’re not limited to that. NXP have also supplied free offline development tools based on the Eclipse IDE.

Hardware specification

The board is based on the NXP LPC812 with an ARM Cortex-M0+ Core running at 30 MHz. The LPC812 has 16KB flash memory, and 4KB RAM. For I/O you have 3 x USARTs, 2 x SPI ports,  one comparator, and one I2C port. The serial lines are brought out to a separate serial expansion connector to allow easy connection to a range of expansion boards from the manufacturer. An RGB LED is fitted to the board for all the “hello, world” fun you could want, and for extra I/O (and I2C practice) there’s a four-channel NXP PCF8591 ADC (and also gives you one DAC as well – convenient) along with a PCA9672 I/O expander IC for more GPIO. 

If you’re using the offline development IDE you can also make use of the NXP hardware debugging interface as well. Users of the physically-narrow range of NXP LPC development boards will also recognise the two parallel rows of pinouts down the length of the PCB, and Arduino users will recognise the header sockets (more on those later). When you receive the board – you just receive the board, so you’ll need a typical microUSB cable. Finally, you can download the LPC800 MAX schematic for further examination.

What is mbed anyway?

mbed is a completely online development environment. That is, in a manner very similar to cloud computing services such as Google Docs. However there are some pros and cons of this method. The pros include not having to install any software on the PC – as long as you have a web browser and a USB port you should be fine; any new libraries or IDE updates are handled on the server leaving you to not worry about staying up to date; and the online environment can monitor and update your MCU firmware if necessary.

However the cons are that you cannot work with your code off-line (no working in-flight) and there may be some possible privacy issues. Here’s an example of the environment:

mbed compiler screen

As you can see the IDE is quite straight-forward. All your projects can be found on the left column, the editor in the main window and compiler and other messages in the bottom window. There’s also an online support forum, an official mbed library and user-submitted library database, help files and so on – so there’s plenty of support.

Code is written in C/C++ style and doesn’t present any major hurdles. When it comes time to run the code, the online compiler creates a downloadable binary file which is copied over to the hardware via USB, from which point you reset the board and off it goes.

If you’re using the LPC800-MAX with mbed, be sure to follow the “Getting Started” guide and also check for the latest firmware from the mbed handbook. And although the mbed board appears as a USB storage device, you can still have serial communication with a PC using a virtual serial port via the USB cable connected between the PC and the LPC800-MAX.

Arduino form-factor compatibility

You will notice the header sockets physically match the Arduino Uno R3 specification, so you can drop in an Arduino shield. However the board runs on 3.3V and is 5V-tolerant, so it’s preferable your shields or new designs are good for 3.3V operation. Furthermore, as the onboard LPC812 doesn’t have as much analogue and digital I/O as an ATmega328P found on the Arduino Uno, the extra I/O are provided by two external ICs via I2C. Four analogue inputs are provided by the onboard NXP PCF8591 ADC (and also gives you one DAC as well – convenient) – and the equivalent A4 and A5 pins are not ADC, instead they’re just I2C SDA and SCL respectively.

The extra digital I/O pins are provided via I2C by the aforementioned PCA9672 I/O expander IC. Upon reflection you’d have to be very keen to use a specific Arduino shield as some extra coding would be required to deal with the required I/O – however on the other hand you can easily add external circuitry with blank Arduino protoshields for new projects. Finally, here’s a pin map of the shield connectors.

LPC-800 pin map

Not a fan of mbed? Offline tools

NXP have also made their LPCXpressoIDE based on Eclipse available for free download for all platforms – http://lpcware.com/lpcxpresso/download. The free version is good for up to 256 KB code size (provided you register the software) which more than covers the requirements for this and other LPC800 products:

LPCXpresso IDE screenshot

For more information and support, there is a huge repository of information on the NXP website.

Where to get an LPC800-MAX

The board is manufactured and sold by Embedded Artists. At the time of writing the board retails for €15, which is around US$21. NXP also have a range of LPC800 microcontrollers, including very inexpensive through-hole 8-pin versions which are available from the usual retailers. And adafruit of all places have a US$13 starter pack based around the DIP LPC810, which is an interesting 32-bit alternative to the ATtinys out there.

Conclusion

If you’re interested in working with the NXP LPC800-series of microcontrollers, the LPC800-MAX board is a very convenient development board considering the included debugger, Arduino protoshield capability, external GPIO expander and ADC/DAC and onboard LED – as well as the free IDE.

If you enjoy the mbed development environment, the board gives you another hardware option. However if you’re an Arduino user looking for a cheap way of getting a faster board whilst using your existing environment – this is not for you. The product under review was purchased without the knowledge of the supplier.

Full-sized images can be found on flickr. And while you’re here – are you interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in LPC800, LPC800-MAX, LPCxpresso, mbed, review, tronixstuff0 Comments

Review – Freetronics 128×128 Pixel Colour OLED Module

Introduction

Time for another review, and in this instalment we have the new 128×128 Pixel OLED Module from Freetronics. It’s been a while since we’ve had a full-colour graphic display to experiment with, and this one doesn’t disappoint. Unlike other displays such as LCD, this one uses OLED – “Organic Light-Emitting Diode” technology.

OLEDs allow for a faster refresh rate, and to the naked eye has a great amount of colour contrast. Furthermore the viewing angles are excellent, you can clearly read the display from almost any angle, for example:

freetronics OLED display bottom view

freetronics OLED display side

However they can suffer from burn-in from extended display of the same thing so that does need to be taken into account. Nevertheless they provide an inexpensive and easy-to-use method of displaying colour text, graphics and even video from a variety of development boards. Finally – there is also a microSD socket for data logging, image storage or other uses. However back to the review unit. It arrives in typical retail packaging:

freetronics OLED display

and includes the OLED display itself, a nifty reusable parts tray/storage box, and two buttons. The display has a resolution of 128 x 128 pixels and has a square display area with a diagonal size of 38.1 mm. The unit itself is quite compact:

freetronics OLED display front

freetronics_OLED_display_rear

The display is easily mounted using the holes on the left and right-hand side of the display. The designers have also allowed space for an LED, current-limiting resistor and button on each side, for user input or gaming – perfect for the  included buttons. However this section of the PCB is also scored-off so you can remove them if required. Using the OLED isn’t difficult, and tutorials have been provided for both Arduino and Raspberry Pi users.

Using with Arduino

After installing the Arduino library, it’s a simple matter of running some jumper wires from the Arduino or compatible board to the display – explained in detail with the “Quickstart” guide. Normally I would would explain how to use the display myself, however in this instance a full guide has been published which explains how to display text of various colours, graphics, displaying images stored on a microSD card and more. Finally there’s some interesting demonstration sketches included with the library. For example, displaying large amounts of text:

… the variety of fonts available:

freetronics OLED font demonstration

… and for those interested in monitoring changing data types, a very neat ECG-style of sketch:

… and the mandatory rotating cube from a Freetronics forum member:

Using with Raspberry Pi

For users of this popular single-board computer, there’s a great tutorial and some example videos available on the Freetronics website for your consideration, such as the following video clip playback:

Support

Along with the Arduino and Raspberry Pi tutorials, there’s also the Freetronics support forum where members have been experimenting with accelerated drivers, demonstrations and more.

Competition!

For a chance to win your own OLED display, send a postcard with your email address clearly printed on the back to:

OLED Competition, PO Box 5435 Clayton 3168 Australia. 

Cards must be received by 24/10/2013. One card will then be selected at random and the winner will be sent one Freetronics OLED Display. Prize will be delivered by Australia Post standard air mail. We’re not responsible for customs or import duties, VAT, GST, import duty, postage delays, non-delivery or whatever walls your country puts up against receiving inbound mail.

Conclusion

Compared to previous colour LCD units used in the past, OLED technology is a great improvement – and demonstrated very well with this unit. Furthermore you get the whole package – anyone call sell you a display, however Freetronics also have the support, tutorials, drivers and backup missing from other retailers. So if you need a colour display, check it out.

And for more detail, full-sized images from this article can be found on flickr. And if you’re interested in learning more about Arduino, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

[Note – OLED display was a promotional consideration from Freetronics]

Posted in arduino, freetronics, LCD, OLED, product review, raspberry pi, review, tutorial0 Comments

First look – Arduino Yún

Introduction

After being announced in May this year, the new Arduino Yún has arrived in the crowded marketplace – and I snapped up one of the first to arrive in Australia for an initial review. The purpose of which is to run through the out of box experience, and to see how easy it was to get the Yún working with the promised new features.

[Update – over time we’ll publish tutorials specifically for the Yún, which are listed here.]

The Yún introduces some interesting new combinations of hardware and connectivity, all within the familiar form-factor. Which gives us plenty to examine and write about, so let’s get started. First, a quick look around the Yún:

Arduino Yun Yún front

Notice the stickers on the header sockets, useful for beginners or the absent-minded…

Arduino Yún Yun right side

The usual TX/RX and D13 LEDs, plus notifiers for power, WiFi, LAN and USB use…

Arduino Yún Yun sockets

Ethernet, USB programming, USB host…

Arduino Yun Yún top side

Again with the stickers…

Arduino Yun Bottom Yún

The rear is quite busy. You can also see “Made in Taiwan” – a first for Arduino. I believe the reason for this was due to the new Atheros chipset requirements. Did you notice the multiple reset buttons? There are three – one for the Arduino, one for wifi and one to reboot Linino. As you can see there’s a lot of circuity on the bottom of the Yún, so it would be prudent to use some short standoffs to elevate the board and protect the bottom. Before moving on, you might like the following video where the Arduino team introduce the Yún:

Specifications

The Yún is based around the Arduino Leonardo-specification board – thus you have the ATmega32U4 microcontroller and the usual Leonardo functions. Note you cannot feed wild DC voltages into the Vin pin – it must be a regulated 5V. And the DC socket has gone, so for a solid connection you might want to make or buy your own power shield.

However there is so much more… underneath a small metal shield below the digital I/O pins is an Atheros AR9331 CPU running a Linux distribution based on OpenWRT named Linino. This Atheros part of the board is connected to a microSD socket, 10/100 Ethernet port, a USB 2.0 socket for host-mode functions and also has IEEE 802.11b/g/n WiFi, and Power-over-Ethernet support (with an optional adaptor).

And all of that is connected to the Arduino side of things via a simple serial “bridge” connection (with it’s own library) – which gives the Arduino side of the board very simple methods of controlling the other onboard hardware.

Getting started with the Yún WiFi

First thing is to download and install the new IDE, version 1.5.4. This is for Due and Yún, so keep your older installations as well. On the general Arduino side of things nothing has changed, so we’ll move on to the more interesting side of the board. The first of these is to setup and experiment with the onboard WiFi. After connecting your board to USB for power, you can connect to it with your PC’s WiFi:

Arduino Yun Yún office wifi

… at which point you connect to the Yún network. Then visit 192.168.240.1 from a web browser, and you’re presented with a page that asks for the default password, which is … “arduino”:

Arduino Yún Yun wifi setup

At which point you’re presented with the relevant details for your Yún:

Arduino Yún  Yun wifi details

… such as the IP address, MAC address, etc. Make note of your MAC address, you might need it later. From here you can configure the Yún WiFi details, for example the name and password, and also the details of your existing WiFi network which can be used to access the Yún. Once you save those, the Yún reboots and tells you to connect the PC back to the existing WiFi network:

Arduino Yun Yún WiFi setup complete

If for some reason it doesn’t work or you entered the wrong settings – hold down the “WLAN RST” button (next to the USB host socket) for five seconds. This sets the WiFi details in the Yun back to the default … and you can start all over again.

Note that the Yún’s preset IP of 192.168.240.1 may not be suitable for your own network. For example, if your home router is 10.1.1.1 you need to do some detective work to find out the IP address for the Yún. Head into your router’s administration pages and look for your DHCP Client Log. It will show a list of devices that are connected to the network, including their MAC and IP address – for example:

Arduino Yún Yun new IP address DHCPThen it’s a simple matter of finding the MAC address in the list and the matching IP. Once you have the IP address, enter that into a web browser and after being prompted for the Yún’s password, you’re back to the welcome page with the IP, MAC addresses etc.

WiFi Sketch Uploading

Once your Yún is on the same WiFi network as the PC running the IDE – you can upload a sketch over WiFi! This is possible due to the bridge between the Atheros section on the board and the Arduino hardware. Just select the board type as normal in the IDE, and the port (the IP address version):

Arduino Yun WiFi sketch upload  Yún

… then hit Upload as normal, enter the password:

Arduino Yun WiFi sketch upload  Yún

and you’re done. Awesome.

Console-based control of Arduino over WiFi

There’s a neat example that demonstrates how you can control the Arduino over the WiFi using a console terminal on the PC. Upload this sketch (from http://arduino.cc/en/Guide/ArduinoYun#toc13):

Then load your terminal software. We use PuTTY on Windows. Run the terminal software, then login as root, then telnet to “localhost 6571”:

Arduino Yún  Yun terminal console putty

You can then send characters to the Yún just as you would with a USB-connected Arduino via the serial monitor. With the example above you’re turning the D13 LED on and off, but you can get the idea.

The “Internet of Things”

Arduino has teamed up with a service called “Temboo” – which gives you over 100 APIs that your Yún can hook up with to do a myriad of things, such as send tweets, get weather data from Yahoo, interact with Dropbox, etc. This is done easily and explained quite well at the Temboo website. After signing up for Temboo (one account seems to be free at the moment) we tried the Yahoo weather API.

You enter the parameters using an online form in Temboo (in our example, the address of the area whose weather forecast we required), and the Temboo site gives you the required Arduno sketch and header file to upload. And you’re done. With this particular example, I wanted the weather in Sydney CBD – and once running the data is returned to the serial monitor, for example:

Temboo Arduino Yun yahoo weather Yún

It was great to see that work the very first time, and a credit to Temboo and Arduino for making it happen. But how?

There is a Temboo client in the Linino OS, which is the gateway to the API via WiFi, and also communicates with the Arduino via the serial bridge. The Arduino Temboo library can then interact with the Linino client without complex code. The weather data is then returned back from the Internet via the Temboo client and fed to the Arduino serial port, where you can parse it with your own code. This looks like a lot of fun, and also could be quite useful – for example capturing data and sending it to a Google Docs spreadsheet. For more information, check out the Temboo website.

However you can delve deeper and create your own APIs, matching code – and perhaps other services will develop their own APIs in the near future. But for now, it’s a good start.

Where to from here? And support?

This article has only scratched the surface (but not bad considering the board arrived a few hours ago). There’s plenty more examples on the getting started page, in the IDE (under “Bridge”) – plus a dedicated Arduino Yún forum. And check out this gmail notifier. In the near future we’ll create some of our own tutorials, so stay tuned.

Is the Yún a completely open-source product? 

Well it says “open source electronics prototyping platform” on the rear, but is this true? The Arduino Leonardo-side of the board is. However the Atheros AR9331 chip is not. Nevertheless, are you really going to reproduce your own AR9331? So it doesn’t really matter. Being a pragmatist I propose that the Yún solves the problem of Arduino and Internet connectivity quite well for the non-advanced user – so not being totally OSHW isn’t an issue.

Support

This board is very new to us here, so for questions or support please ask on the dedicated Arduino Yún forum.

Conclusion

Since the popularity of various single-board computers has increased exponentially over the last few months, some may say that the Yún is perhaps too little, too late. After only having the Yún for a few hours before writing this article, personally I disagree with this statement – the Yún is a device that still gives us the wide range of hardware control, and what looks to be a very simple method of connectivity that surely is cheaper and less prone to issues than the original Arduino WiFi shield.

What the Yún gives us is a simple, well-executed method of getting our Arduino connected to the outside world – and in a manner that won’t confuse or put off the beginner or intermediate user. So for now, it’s a win.

What do you think? Leave a comment below.

And for more detail, full-sized images from this article can be found on flickr. And if you’re interested in learning more about Arduino, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in AR9331, Atheros, lesson, Linino, linux, review, temboo, tronixstuff, tutorial, Uncategorized, wifi, Yún8 Comments

Initial Review – Goldilocks Arduino-compatible with ATmega1284P

Introduction

In March this year we discussed a project by Phillip Stevens to crowd-fund an Arduino-compatible board with an ATmega1284p microcontroller – the “Goldilocks”. After being funded at a rapid rate, and subjected to some community feedback – the boards have now been manufactured and delivered to those who pledged. If you missed out – there’s some more available for direct sales. We ordered five and now have them for the subject of this review – and two to give away. So let’s examine the board and see what’s new.

What is it?

After hitting the limits of the Arduino Uno with respect to SRAM, CPU speed and not wanting to lose compatibility with existing projects by changing platforms, Philip decided to shift the MCU up to the ATmega1284P. This offers eight times the SRAM, four times the flash memory and EEPROM – and is also clocked at 20 MHz instead of the usual 16 MHz on Unos, etc. After the original design was announced, it was the victim of some pretty heavy feature-creep – however with Freetronics as the manufacturing partner the final result is a nicely-finished product:

freetronics goldilocks

Now let’s rip open the packaging and examine the board in greater detail. From the images below you can get the gist of things… starting with the top you can see the ATmega1284P next to the microSD card socket. There’s a JTAG connector for the 1284P on its left – and below that a 32.768 kHz crystal for RTC use. And like other Freetronics boards a large prototyping area has been squeezed in below pins D0~7 that also has the power and I2C lines at the edge. Furthermore note that all I/O pins are brought out to separate holes in alignment with the header sockets. And my favourite – a switch-mode power supply circuit that can offer up to 2A of current – great for GSM shields.

freetronics goldilocks top

Another point of interest is the ATmega32U2 microcontroller which is for USB duties – however it can be used as a separate “board” on its own, with a separate reset button, ICSP breakout and the ports are broken out logically:

freetronics goldilocks atmega32u2

Furthermore the 32U2’s SPI bus can be wired over to the main 1284P to allow communication between the two – simply by bridging the provided pads on the PCB you can join them. Also on the bottom you can see how each I/O pin can be disconnected from the I/O areas and thus diverted if necessary. It really is a testament to the design that so much of the board is customisable, and this attention to detail makes it stand apart from the usual Arduino-compatibles out there.

freetronics goldilocks bottom

One thing that did strike me was the retina-burning intensity of the onboard LEDs – however you can disable them by cutting the provided track on the PCB. For a complete explanation of the hardware side of things, check out the user guide.

Using the Goldilocks

One of the main goals was to be Arduino Uno R3-compatible, and from initial examination this is certainly the case. However there are a couple of differences, which you can find out more about in the user guide. This is not the first board for an Arduino user, but something chosen after getting some experience. Installation was very easy, it should be plug-and-play for the non-Windows crowd. However if you’re part of the silent majority of Windows users then the required U2duino Programmer.inf file for the Device Manager will be found in the production_firmware folder of the software download available on the product page. Furthermore no matter your OS – don’t forget to install the Arduino IDE Goldilocks board profile.

Before getting too excited and uploading your sketches, you can examine the the ATmega1284p bootloader monitor which allows for memory dumps, port testing, and more. Simply connect up your board, load the Arduino IDE, select the board and COM: port then open the Serial Monitor. By sending “!!!” after a board reset, a simple menu appears – which is shown in the following video:

Now for a quick speed test. We’ll use a sketch written by Steve Curd from the Arduino forum. It calculates Newton Approximation for pi using an infinite series:

The Goldilocks was compared with a standard Arduino Uno, with the following results (click image to enlarge):

goldilocks Uno speed test

 As you can see from the results below, the Goldilocks theoretical extra 4 Mhz of speed is shown in the elapsed time between the two boards – 4433 ms for the Goldilocks vs. 5562 ms for the Uno, a 25.4% increase. Looking good. We’ll leave it for now – however for more information you can review the complete user manual, and also discuss Goldilocks in the Freetronics customer forum.

Competition

Two of our twitter followers will be randomly selected on the 14th of September, and will each receive one Goldilocks board. So follow us on @tronixstuff for a chance to win a board, and also keep up with news, new articles and items of interest. Board will be delivered by Australia Post standard air mail. We’re not responsible for customs or import duties, VAT, GST, import duty, postage delays, non-delivery or whatever walls your country puts up against receiving inbound mail.

Conclusion

The Goldilocks is the board that can solve many problems – especially when you’ve outgrown your Uno or similar board. We look forward to using it with larger projects that burn up SRAM and exploring the possibilities of using the two microcontrollers at once. There’s a whole bundle of potential – so congratulations to Phillip Stevens, Freetronics and all those who pledge to the funding and supported the project in general. And to join in – you can get your own from Freetronics. Full-sized images are on flickr. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, atmega1284p, atmel, freetronics, review, tronixstuff

Part review – Freetronics HBRIDGE motor driver shield for Arduino

Introduction

Controlling motors with an Arduino is a fun and generally integral part of the learning process for most up-and-coming embedded electronics enthusiasts. Or quite simply, using motors is fun ’cause you can make robots, tanks and stuff that moves. And thanks to Freetronics we have their new HBRIDGE motor shield for Arduino to review, so let’s check it out and get some things moving with it.

Arriving in retail-friendly packaging, the HBRIDGE can be stored with the included reusable packaging, and also has a quick-start guide that explains the technical specifications and URLs for tutorials:

HBRIDGE

The shield is compatible with the latest R3-series Arduino boards including the Leonardo and of course the Freetronics Eleven board:

HBRIDGE shield Freetronics Eleven

Specifications

The HBRIDGE shield is based on the Allegro A4954 Dual Full-Bridge DMOS PWM Motor Driver. For the curious, you can download the data sheet (pdf). This allows very simple control of two DC motors with a maximum rating of 40V at 2A, or one bipolar stepper motor. Unlike other motor shields I’ve seen, the HBRIDGE has a jumper which allows the power supply for the motor shield to be fed into the Arduino’s Vin line – so if your motor power supply is under 12V DC you can also power the Arduino from the same supply. Or you can run the motors from the Arduino’s power supply – if you’re sure that you won’t exceed the current rating. Frankly the former would be a safer and this the preferable solution.

The motor(s) are controlled very simply via PWM and digital logic. You feed the A4954 a PWM signal from a digital output pin for motor speed, and also set two inputs with a combination of high/low to set the motor direction, and also put the motor controlled into coast or brake mode. However don’t panic, it’s really easy.

Using the shield

How easy? Let’s start with two DC motors. One example of this is the tank chassis used in Chapter 12 of my book “Arduino Workshop – A Hands-On Introduction with 65 Projects“:

arduino_workshop_tank

The chassis is pretty much a standard tank chassis with two DC motors that run from an internal 9V battery pack. Search the Internet for “Dagu Rover 5” for something similar. Connection is a simple manner of feeding the power lines from the battery and the motor wires into the terminal block on the HBRIDGE shield.

Next, take note of two things. First – the slide switches below the jumpers. Using these you can select the maximum amount of current allowed to flow from the power supply to each motor. These can be handy to ensure your motor doesn’t burn out by drawing too much current in a stall situation, so you can set these to the appropriate setting for your motor – or if you’re happy there won’t be any issues just leave them both on 2A.

The second thing to note is the six jumpers above the switches. These control which digital pins on your Arduino are used to control the motor driver. Each motor channel requires two outputs and one PWM output. If you leave them all on, the Arduino pins used will be the ones listed next to each jumper, otherwise remove the jumpers and manually wire to the required output. For the purposes of our demonstration, we’ll leave all the jumpers in. A final word of warning is to be careful not to touch the A4954 controller IC after some use – it can become really hot … around 160 degrees Celsius. It’s the circled part in the image below:

A4954_controller_IC

So back to the DC motors. You have two digital outputs to set, and also a PWM signal to generate – for each channel. If you set the outputs to 1 and 0  – the motor spins in one direction. Use 0 and 1 to spin the other way. And the value of the PWM (0~255) determines the speed. So consider the following sketch:

Instead of chasing the tank chassis with a camera, here it is on the bench:

Now to try out a stepper motor. You can control a bipolar motor with the HBRIDGE shield, and each coil (pole) is connected to a motor channel.

Hint – if you’re looking for a cheap source of stepper motors, check out discarded office equipment such as printers or photocopiers. 

For the demonstration, I’ve found a random stepper motor from a second-hand store and wired up each pole to a channel on the HBRIDGE shield – then run the Arduino stepper motor demonstration sketch by Tom Igoe:

With the following results:

Considering it was a random stepper motor for which we didn’t have the specifications for – it’s always nice to have it work the first time! For more formal situations, ensure your stepper motor matches the power supply voltage and so on. Nevertheless it shows how easy it can be to control something that appears complex to some people, so enjoy experimenting with them if you can.

Competition

Thanks to Freetronics we have a shield to give away to one lucky participant. To enter, clearly print your email address on the back of a postcard and mail it to:

H-Bridge Competition, PO Box 5435 Clayton 3168 Australia.

Entries must be received by the 20th of  September 2013. One postcard will then be drawn at random, and the winner will receive one H-Bridge shield delivered by Australia Post standard air mail. One entry per person – duplicates will be destroyed. We’re not responsible for customs or import duties, VAT, GST, import duty, postage delays, non-delivery or whatever walls your country puts up against receiving inbound mail.

Conclusion

As demonstrated, the HBRIDGE shield “just works” – which is what you need when bringing motorised project ideas to life. The ability to limit current flow and also power the host board from the external supply is a great idea, and with the extra prototyping space on the shield you can also add extra circuitry without needing another protoshield. Very well done. For more information and to order, visit the Freetronics website. Full-sized images are on flickr. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

tronixstuff

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Note – The motor shield used in this article was a promotional consideration supplied by Freetronics.

Posted in A4954, freetronics, HBRIDGE, part review, review, stepper motor, tronixstuff, tutorial2 Comments

Visualise microcontroller data with Megunolink Pro

Introduction

When the time comes to capture data from a microcontroller-based project, or control an embedded project via a PC – the thought of writing the appropriate PC software can give some people a headache. Or if you’re an Arduino or other development board user and are frustrated with the Serial Monitor box – where do you go? These problems and many more can be solved by using the Megunolink Pro software that’s the subject of this review.

From the Megunolink website,

MegunoLink Pro is a tool designed to aid embedded electronics designers. MegunoLink provides a set of tools to help visualize serial data, it is made up of a set of visualizers that each have a unique function and any number of them can be utilized at once. With these visualizers and our functional tabbed and docked interface you can create a full control center for your embedded project. Plot, log and monitor serial streams from both hardwired, bluetooth, and network based (UDP) devices.

The user interface allows for a completely customized layout with many different visualisers displaying information at once. Perfect for developing exciting new microcontroller based designs. Data streams go from hard to follow serial messages to easy to interpret tables and interactive plots. The interface panel allows you to set up custom GUI elements that let you take control of your device from the comfort of your PC screen.

Phil from Megunolink gives us a quick demonstration in the following video:

Installation

Getting Megunolink running takes around ten minutes. You’ll need a recent PC running Windows of some variety (XP/ 2003/Vista/Win7/8) and also .NET Framework v4.0. You can download a trial Pro version which operates for seven days – at which point you can use the “lite” version or purchase a Pro license. The Megunolink team have given our readers a discount on the personal version, use the coupon code “TROMLP” for 30% off.

Operation

Using Megunolink is quite simple, even though there’s a whole pile of functions. From the home page there’s a variety of documentation for all of the software features, so you can get started very quickly. You can simply capture all output from the serial line and have it saved to a text file (and with a time/date stamp, which removes the need for a RTC in the hardware) – something which seems quite simple but not done with the Arduino IDE:

rtccapture

Furthermore there is an “upload monitor” in Megunolink – which can automatically disconnect from the COM: port used by an Arduino when you need to upload a new sketch, then reconnect afterward. This saves a lot of to-and-fro between the two programs when adjusting code.

The key to analysing data from the microcontroller is to insert text notes in the serial output, which are then interpreted by Megunolink for display purposes. For example, if you have your MCU code send labels with the data, Megunolink can then sort these out into channels and graph the data, for example:

timeplot_screencapture

An example Arduino sketch is provided to demonstrate this, and it translates to other development platforms. Another great feature is the ability to create a graphical user interface for projects connected to the PCB. You design the GUI which can include buttons, sliders and numeric fields, for example:

controls

… and each of which send values of your choice to the device via USB. Then it’s a simple matter of coding your device to respond to the serial commands.

Real-time mapping

As mentioned in the video above, there’s also mapping support – your hardware sends GPS coordinates and they’re displayed in a real-time window:

mapping

Arduino programming

There’s also an interface to allow programming of an Arduino with .hex files via Megunolink. Currently it can work with the ATmega328, -2560, and with an external programmer -328P and -644 microcontrollers.

Conclusion

Once again Megunolink has proven to be a useful piece of software. It gives you a friendly and powerful connection to all the data from your microcontroller, and also a simple GUI for control via serial. So test it for yourself, it won’t cost you anything for the trial version. And if you like it – don’t forget about the tronixstuff.com discount on the personal version – use the coupon code “TROMLP” for 30% off. Finally, if you have any questions please contact Megunolink. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

[Note – Megunolink Pro software license was a promotional consideration]

 

Posted in arduino, data, data analysis, graphing, mapping, megunolink, review, software, software review, tronixstuff2 Comments

Tutorial – 74HC4067 16-Channel Analog Multiplexer Demultiplexer

Introduction

Now and again there’s a need to expand the I/O capabilities of your chosen micorocontroller, and instead of upgrading you can often use external parts to help solve the problem. One example of this is the 74HC4067 16-channel analog multiplexer demultiplexer. That’s a mouthful – however in simple form it’s an IC that can direct a flow of current in either direction from one pin  to any one of sixteen pins. Another way to think abou it is that you can consider the 74HC4067 to be a digital replacement to those rotary switches that allow you to select one of sixteen positions.

Here’s an example of the SMD version:

74HC4067

Don’t let that put you off, it’s just what we had in stock at the time. The part itself is available in through-hole and surface mount versions.

Using the 74HC4067

At this point you should download the data sheet, as we refer to it through the course of the article. The first thing to note is that the 74HC4067 can operate on voltages between 2 and 6V DC, which allows use with 3.3V and 5V microcontrollers and boards such as Arduino and Raspberry Pi. If for some reason you have the 74HCT4067 it can only work on 4.5~5.5V DC.  Next – consider the pinout diagram from the data sheet:

74HC4067 pinoutThe power supply for the part is applied to pin 24, and GND to … pin 12. Pin 15 is used to turn the control the current flow through the inputs/outputs – if this is connected to Vcc the IC stops flow, and when connected to GND it allows flow. You can always control this with a digital output pin if required, or just tie it to GND if this doesn’t matter.

Next – pin one. This is where the current either flows in to be sent to one of the sixteen outputs – or where the current flows out from one of the sixteen inputs. The sixteen inputs/outputs are labelled I0~I15. Finally there are the four control pins – labelled S0~S3. By setting these HIGH or LOW (Vcc or GND) you can control which I/O pins the current flow is directed through. So how does that work? Once again – reach for the the data sheet and review the following table:

74HC4067 truth tableNot only does it show what happens when pin 15 is set to HIGH (i.e. nothing) it shows what combination of HIGH and LOW for the control pins are required to select which I/O pin the current will flow through. If you scroll down a bit hopefully you noticed that the combination of S0~S3 is in fact the binary equivalent of the pin number – with the least significant bit first. For example, to select pin 9 (9 in binary is 1001) you set the IC pins S0 and S3 to HIGH, and S1 and S2 to LOW. How you control those control pins is of course up to you – either with some digital logic circuit for your application or as mentioned earlier with a microcontroller.

Limitations 

Apart from the power supply requirements, there are a few limitations to keep in mind. Open you data sheet and consider the “DC Electrical Specifications” table. The first two parameters show what the minimum voltage that can be considered as a HIGH and the maximum for a LOW depending on your supply voltage. The next item of interest is the “ON” resistance – that is the resistance in Ohms (Ω) between one of the sixteen inputs/outputs and the common pin. When a channel is active, and a 5V supply voltage, we measured a resistance of 56Ω without a load through that channel – and the data sheet shows other values depending on the current load and supply voltage. Finally, don’t try and run more than 25 mA of current through a pin.

Examples

Now to show an example of both multiplexing and demultiplexing. For demonstration purposes we’re using an Arduino Uno-compatible board with the 74HC4067 running from a 5V supply voltage. Pin 15 of the ‘4067 is set to GND, and control pins S0~S3 are connected to Arduino digital output pins D7~D4 respectively.

Multiplexing

This is where we select one input pin of sixteen and allow current to flow through to the common pin (1). In this example we connect the common pin to the board’s analog input pin – so this can be used as a method of reading sixteen analog signals (one at a time) using only one ADC. When doing so – take note of the limitations mentioned earlier – take some resistance measurements in your situation to determine what the maximum value will be from your ADC and calibrate code accordingly.

With both of the examples we’ll use port manipulation to control the digital pins which are connected to the 74HC4067’s control pins. We do this as it reduces the code required and conceptually I feel it’s easier. For example – to select I/O 15 you need to turn on all the control pins – so you just have to set Arduino PORTD to B11110000 (which is binary 15 LSB first) and much neater than using four digitalWrite() functions.

In the following example sketch, you can see how we’ve put the binary values for each control possibility in the array byte controlPins[] – which is then used to set the pins easily in void loop().

This simply sets each input pin in turn, then reads the ADC value into an array – whose values are then sent to the serial monitor:

… and a quick video of the results:

Demultiplexing

Now for the opposite function – sending current from the common pin to one of sixteen outputs. A fast example of this is by controlling one of sixteen LEDs each connected to an output pin, and with 5V on the 74HC4067 common pin. We don’t need current-limiting resistors for the LEDs due to the internal resistance in the 74HC4067. Here’s the sketch:

… and the LEDs in action:

Conclusion

If you’re considering the 74HC4067 or hadn’t known about it previously, we hope you found this of interest. If you have any questions please leave them below or privately via the contact page. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

 

Posted in 74HC4067, arduino, Demultiplexer, Multiplexer, part review, review, tronixstuff, tutorial13 Comments

Review – adafruit industries Mini 8×8 LED Matrix with I2C backpack

Introduction

In this review we have a look at the mini 8×8 LED matrix with I2C backpack from adafruit industries. It looked like a small yet versatile display unit for a couple of project ideas, so as part of the evaluation we’ll run through it with you here. As you can see below, it’s quite small with a 20mm square matrix:

contents

The matrix and the controller are seperate which gives you the option of ordering different colours of matrix. Using LED matrices can be a pain, however these units use the Holtek 16K33 controller IC (data sheet) which has an I2C interface – much easier than the usual mess of shift registers and I/O pins:

holtek

 Furthermore you can change the I2C address using the solder pads on the PCB, giving you four possible options. And as it’s I2C, you can use it with other microcontrollers with a little detective work. Moving forward, we’ll assemble the display then explain how to use it with an Arduino, and show a few demonstrations.

Assembly

There really isn’t anything major to do, just solder the matrix to the backpack and some header pins if you need them. adafruit include some however I’m using the 90-degree ones for my own use:

solderingpins

The soldering should take about one minute tops, and then you’re done:

finished

Using the matrix

From a hardware perspective you only have four wires – 5V, GND, SDA and SCL. Yes – it’s a 5V part, so all you Raspberry Pi fans will need a level shifter, which you can get from adafruit as well. Anyhow once you’ve got it connected to your Arduino, a couple of libraries are required – the matrix and GFX libraries. Be sure to install them in your sketchbook/libraries folder and not the usual location. When saving the library files, call the first folder Adafruit_LEDBackpack and the second Adafruit_GFX as they don’t arrive in that format.

Now for a quick demonstration, it’s simply one from the included library. The display is very bright, so I had to reduce the exposure on the camera which makes the background a little dark – but you get the idea:

A pair of those fitted to a dummy or doll would be quite interesting, or make good eyes for a 21st century “Metal Mickey”. Well that’s quite interesting, so how do you in fact display things on the matrix? I’ve deconstructed a few examples to show you how it’s done.

No matter what, you need to include the libraries, define the matrix object in the sketch and then start it with the matching I2C address – for example:

To scroll text across the display, modify the following chunk of code:

First, the setRotation() value is 0~3 and determines which way the text scrolls across the screen. This is useful if you mount the matrix in different positions, as you can still keep the text scrolling in a readable manner. Next, matrix.setTextWrap() – leave this as false,  as true displays each character and then just scrolls it in turn – looking rather odd. Now multiply the number of characters you want to display by 8, and replace the number -96 with negative your value and of course “Hello, world”. Finally follow with rest of the code. There’s a quick demonstration of this code in the sketch and video below:

 

Now for some graphics. You can define your own images (!) and store them in an array. Each arrays consists of eight bytes, each representing a row of the matrix. You can use binary to help visualise the results, for example:

and then to display that on the matrix, use the following:

… which resulted with:

crosshatch

To control individual pixels, send one or more of the following:

where x and y are the pixel’s coordinates (that fall between zero and seven), followed by:

Here’s a neat example sketch and video of a single pixel “running around the border”:

By this point you should be getting the hang of things now, so we’ll finish up with the last three graphic functions at once. To draw a line between x1, y1 and x2, y2 – use:

To draw a rectangle with corners at x1, y2, x2, y2 – use:

To draw a filled rectangle with corners at x1, y2, x2, y2 – use:

And to draw a circle with axis at x,y and a radius of r pixels – use:

Now we’ll put those functions into the following sketch and video:

 

If you want to get someone’s attention, you can blink whatever’s on the matrix at various frequencies – and of course turn it off. In the following function, use 0 for off, and 1~3 for different rates:

Finally, you can also adjust the brightness to one of sixteen levels (0~15) using:

That’s enough blinkiness for now. Remember the library is just shielding you from the raw I2C commands, so if you want to create your own functions or use a non-Arduino board – examine the library and the data sheet.

Conclusion

The backpack makes using the matrix an absolute breeze, and the library saves a lot of time and effort – leaving you to get on with creating your ideas into projects. You can get the matrix from adafruit and their distributors.

Full-sized images available on flickr.  And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

[Note – item purchased without notifying the supplier]

Posted in 16K33, adafruit, arduino, holtek, I2C, LED matrix, review, tutorial0 Comments

Kit review – Protostack ATmega32 Development Kit

Introduction

For those of you prototyping with larger Atmel AVR microcontrollers such as the ATmega32, it can be inconvenient to continually assemble a circuit onto a solderless breadboard that includes power, programming header and a few basics – or you might want to create a one-off product without waiting for a PCB to be made. If these are issues for you, or you’re interested in working with AVRs  then the subject of this review may be of interest – the ATmega32 Development Kit from Protostack. The kit is one of a range that spans from the ATmega8, and gives you almost everything needed to work with the microcontroller. We’ve assembled and experimented with the ATmega32 kit, so read on to find out more.

Assembly

The kit arrives in a typical anti-static package with the contents and URL on the front:

packaging

The PCB is large, measuring 127 x 94 mm, made from heavy 1.6 mm FR4 PCB and all the holes are through-plated. And as you can see from the images below, there’s plenty of prototyping space and power/GND rails:

pcbtop

pcbbottom

The included parts allow you to add a power supply, polyfuse, smoothing capacitors for the power, programmer socket, external 16 MHz crystal, a DC socket, IC socket, a lonely LED and of course the ATmega32A (which is a lower-power version of the ATmega32):

parts

You can download the user guide from the product page, which details the board layout, schematic and so on. When soldering the parts in, just start with the smallest-profile parts first and work your way up. There’s a few clever design points, such as power regulator – there’s four holes so you can use both “in-GND-output” and “GND-output-input” types:

igo

… and the layout of the prototyping areas resemble that of a solderless breadboard, and the power/GND rails snake all around – so transferring projects won’t be difficult at all:

protoarea

If you need to connect the AVcc to Vcc, the components and board space are included for a low-pass filter:

lowpass

And if you get carried away and need to use two or more boards at once – they’re stackable:

stacking

Moving forward

After assembling the board and inserting the ATmega32, you can use an AVR programmer to check it’s all working (and of course program it). With a 10-pin interface USBASP inserted, I headed over to the AVRdude folder on my PC and entered:

which (as all was well) resulted with:

avrdudetest2

Awesome – it’s nice to have something that just works. Let the experimenting begin!

Conclusion

It’s a solid kit, the PCB is solid as a rock, and it worked. However it could really have used some spacers or small rubber feet to keep the board off the bench. Otherwise the kit is excellent, and offers a great prototyping area to work with your projects. If you order some, Protostack have a maximum delivery charge of $9 so you won’t get burned on delivery to far-flung places.  Larger photos available on flickr. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

LEDborder

Please note that the ATMEGA32A Development Kit in this review is a promotional consideration from Protostack.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in atmega32, atmel, avr, competition, education, electronics, kit review, microcontrollers, protostack, review, tronixstuff, usbasp0 Comments

Book – “Arduino Workshop – A Hands-On Introduction with 65 Projects”

Over the last few years I’ve been writing a few Arduino tutorials, and during this time many people have mentioned that I should write a book. And now thanks to the team from No Starch Press this recommendation has morphed into my new book – “Arduino Workshop“:

shot11

Although there are seemingly endless Arduino tutorials and articles on the Internet, Arduino Workshop offers a nicely edited and curated path for the beginner to learn from and have fun. It’s a hands-on introduction to Arduino with 65 projects – from simple LED use right through to RFID, Internet connection, working with cellular communications, and much more.

Each project is explained in detail, explaining how the hardware an Arduino code works together. The reader doesn’t need any expensive tools or workspaces, and all the parts used are available from almost any electronics retailer. Furthermore all of the projects can be finished without soldering, so it’s safe for readers of all ages.

The editing team and myself have worked hard to make the book perfect for those without any electronics or Arduino experience at all, and it makes a great gift for someone to get them started. After working through the 65 projects the reader will have gained enough knowledge and confidence to create many things – and to continue researching on their own. Or if you’ve been enjoying the results of my thousands of hours of work here at tronixstuff, you can show your appreciation by ordering a copy for yourself or as a gift 🙂

You can review the table of contents, index and download a sample chapter from the Arduino Workshop website.

Arduino Workshop is available from No Starch Press in printed or ebook (PDF, Mobi, and ePub) formats. Ebooks are also included with the printed orders so you can get started immediately.

LEDborder

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, Arduino Workshop, book, books, cellular, clocks, display, distance, ds1307, DS3232, education, EEPROM, freetronics, GPS, graphic, GSM, hardware hacking, I2C, internet, LCD, learning electronics, lesson, no starch press, numeric keypad, part review, product review, projects, RDM630, RDM6300, relay, review, sensor, servo, SMS, time clock, timing, tronixstuff, tutorial, twitter, wireless, xbee13 Comments

Review – Schmartboard SMT Boards

In this article we review a couple of SMT prototyping boards from Schmartboard.

Introduction

Sooner or later you’ll need to use a surface-mount technology component. Just like taxes and myki* not working, it’s inevitable. When the time comes you usually have a few options – make your own PCB, then bake it in an oven or skillet pan; get the part on a demo board from the manufacturer (expensive); try and hand-solder it yourself using dead-bug wiring or try to mash it into a piece of strip board; or find someone else to do it. Thanks to the people at Schmartboard you now have another option which might cost a few dollars more but guarantees a result. Although they have boards for almost everything imaginable, we’ll look at two of them – one for QFP packages and their Arduino shield that has SOIC and SOP23-6 areas.

boards

QFP 32-80 pin board

In our first example we’ll see how easy it is to prototype with QFP package ICs. An example of this is the Atmel ATmega328 microcontroller found on various Arduino-compatible products, for example:

atmega

Although our example has 32 pins, the board can handle up to 80-pin devices. You simply place the IC on the Schmartboard, which holds the IC in nicely due to the grooved tracks for the pins:

atmegabefore

The tracks are what makes the Schmartboard EZ series so great – they help hold the part in, and contain the required amount of solder. I believe this design is unique to Schmartboard and when you look in their catalogue, select the “EZ” series for this technology. Moving forward, you just need some water-soluble flux:

fluxpen

then tack down the part, apply flux to the side you’re going to solder – then slowly push the tip of your soldering iron (set to around 750 degrees F) down the groove to the pin. For example:

Then repeat for the three other sides. That’s it. If your part has an exposed pad on the bottom, there’s a hole in the centre of the Schmartboad that you can solder into as well:

qfpheat

After soldering I really couldn’t believe it worked, so probed out the pins to the breakout pads on the Schmartboard to test for shorts or breaks – however it tested perfectly. The only caveat is that your soldering iron tip needs to be the same or smaller pitch than the the part you’re using, otherwise you could cause a solder bridge. And use flux!  You need the flux. After soldering you can easily connect the board to the rest of your project or build around it.

Schmartboard Arduino shield

There’s also a range of Arduino shields with various SMT breakout areas, and we have the version with 1.27mm pitch SOIC and a SOT23-6 footprint. SOIC? For example:

soicic

This is the AD5204 four-channel digital potentiometer we used in the SPI tutorial. It sits nicely in the shield and can be easily soldered onto the board. Don’t forget the flux! Although the SMT areas have the EZ-technology, I still added a little solder of my own – with satisfactory results:

The SOT23-6 also fits well, with plenty of space for soldering it in. SOT23? Example – the ADS1110 16-bit ADC which will be the subject of a future tutorial:

ads1110

Working with these tiny components is also feasible but requires a finer iron tip and a steady hand.

sot236

Once the SMT component(s) have been fitted, you can easily trace out the matching through-hole pads for further connections. The shield matches the Arduino R3 standards and includes stacking header sockets, two LEDs for general use, space and parts for an RC reset circuit, and pads to add pull-up resistors for the I2C bus:

otherparts

Finally there’s also three 0805-sized parts and footprints for some practice or use. It’s a very well though-out shield and should prove useful. You can also order a bare PCB if you already have stacking headers to save money.

Conclusion

If you’re in a hurry to prototype with SMT parts, instead of mucking about – get a Schmartboard. They’re easy to use and work well.  Full-sized images available on flickr.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

The boards used in this article were a promotional consideration supplied by Schmartboard.

*myki

Posted in arduino, product review, review, safety, schmartboard, SMD, SMT, soic, soldering, sot-23, tqfp, tronixstuff, tutorial2 Comments

Review – LBE “Magpie” Arduino-compatible board

In this article we review the “Magpie” Arduino Uno-compatible board from Little Bird Electronics.

Introduction

We have a new board to review – the “Magpie” board from Little Bird Electronics in Australia. It seems that a new Arduino-compatible board enters the market every week, thanks to the open-source nature of the platform and the availability of rapid manufacturing. However the Magpie isn’t just any old Arduino Uno knock-off, it has something which helps it stand out from the crowd – status LEDs on every digital and analogue I/O pin. You can see them between the stacking header sockets and the silk-screen labels. For example:

topss

and for the curious, the bottom of the Magpie:

bottomss

At first glance you might think “why’d they bother doing that? I could just wire up some LEDs myself”. True. However having them on the board speeds up the debugging process as you can see when an output is HIGH or LOW – and in the case of an input pin, whether a current is present or not. For the curious the LEDs are each controlled by a 2N7002 MOSFET with the gate connected to the I/O pin, for example:

mosfets

An LED will illuminate as long as the gate voltage is higher than the threshold voltage – no matter the status of the particular I/O pin. And if an I/O pin is left floating it may trigger the LED if the threshold voltage is exceeded at the gate. Therefore when using the Magpie it would be a good idea to set all the pins to LOW that aren’t required for your particular sketch. Even if you remove and reapply power the floating will still be prevalent, and indicated visually – for example:

float

Nevertheless you can sort that out in void setup(), and then the benefits of the LEDs become apparent. Consider the following quick demonstration sketch:

… and the results are demonstrated in the following video:

Apart from the LEDs the Magpie offers identical function to that of an Arduino Uno R2 – except the USB microcontroller is an Atmel 16U2 instead of an 8U2, and the USB socket is a mini-USB and not the full-size type.  For the curious you can download the Magpie design files from the product page.

Conclusion

Another Arduino-compatible board. Having those LEDs on the board really does save you if in a hurry to test or check something.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

 The Magpie board used in this article was a promotional consideration supplied by Little Bird Electronics.

Posted in arduino, clone, compatible, magpie, review, tronixstuff, tutorial, uno5 Comments

First look: Arduino Due

Updated 27/02/2013

Introduction

After much waiting the Arduino Due has been released, so let’s check it out. We’ll run through the specifications and some areas of interest, see what’s different, some random notes – then try out some of the new features. Before moving forward note that it might look the same – the Due is not a drop-in replacement for older boards – even the Mega2560. It’s different.

First announced in late 2011, the Due is the Arduino team’s first board with a 32-bit processor – the Atmel SAM3X8E ARM Cortex-M3 CPU. With an 84 Mhz CPU speed and a host of interfaces and I/O, this promises to be the fastest and most functional Arduino board ever. According to the official Arduino press release:

Arduino Due is ideal for those who want to build projects that require high computing power such as the remotely-controlled drones that, in order to fly, need to process a lot of sensor data per second.
Arduino Due gives students the opportunity to learn the inner workings of the ARM processor in a cheaper and much simpler way than before.
To Scientific projects, which need to acquire data quickly and accurately, Arduino Due provides a platform to create open source tools that are much more advanced than those available now.
The new platform enables the open source digital fabrication community (3d Printers, Laser cutters, CNC milling machines) to achieve higher resolutions and faster speed with fewer components than in the past.

Sounds good – and the Due has been a long time coming, so let’s hope it is worth the wait. The SAM3X CPU holds a lot of promise for more complex projects that weren’t possible with previous ATmega CPUs, so this can be only a good thing.

Specifications

First of all, here’s the Due in detail – top and bottom (click to enlarge):

You can use Mega-sized protoshields without any problem (however older shields may miss out on the upper I2C pins) – they’ll physically fit in … however their contents will be a different story:

The specifications of the Due are as follows (from Arduino website):

Microcontroller AT91SAM3X8E
Operating Voltage 3.3V
Input Voltage (recommended) 7-12V
Input Voltage (limits) 6-20V
Digital I/O Pins 54 (of which 12 provide PWM output)
Analog Input Pins 12
Analog Outputs Pins 2 (DAC)
Total DC Output Current on all I/O lines 130 mA
DC Current for 3.3V Pin 800 mA
DC Current for 5V Pin 800 mA
Flash Memory 512 KB all available for the user applications
SRAM 96 KB (two banks: 64KB and 32KB)
Clock Speed 84 MHz

Right away a few things should stand out – the first being the operating voltage – 3.3V. That means all your I/O needs to work with 3.3V – not 5V. Don’t feed 5V logic line into a digital input pin and hope it will work – you’ll damage the board. Instead, get yourself some logic level converters. However there is an IOREF pin like other Arduino boards which intelligent shields can read to determine the board voltage. The total output current for all I/O lines is also 130 mA … so no more sourcing 20mA from a digital ouput for those bright LEDs.

The power regulator for 5V has been changed from linear to switching – so no more directly inserting 5V into the 5V pin. However the 3.3V is through an LDO from 5v.

Each digital I/O pin can source 3 or 15 mA – or sink 6 or 9 mA … depending on the pin. High-current pins are CAN-TX, digital 1, 3~12, 23~51, and SDA1. The rest are low current. And there’s still an LED on digital 13. You will need to redesign any existing projects or shields if moving to the Due.

The analogue inputs now have a greater resolution – 12-bits. That means it can return a value of  0~4095 representing 0~3.3V DC. To activate this higher resolution you need to use the function analogReadResolution(12).

Memory – there isn’t any EEPROM in the SAM3X – so you’ll need external EEPROMs to take care of more permanent storage. However there’s 512 KB of flash memory for sketches – which is huge. You have to see it to believe it:

Excellent. A new feature is the onboard erase button. Press it for three seconds and it wipes out the sketch. The traditional serial line is still digital 0/1 – which connect to the USB controller chip.

Hardware serial – there’s four serial lines. Pulse-width modulation (PWM) is still 8-bit and on digital pins 2~13.

The SPI bus is on the ICSP header pins to the right of the microcontroller – so existing shields that use SPI will need to be modified – or experiment with a LeoShield:

You can also use the extended SPI function of the SAM3X which allow the use of digital pins 4, 10 or 52 for CS (chip select).

The SAM3X supports the automtive CAN bus, and the pins have been brought out onto the stacked header connectors – however this isn’t supported yet in the IDE.

There are two I2C buses – located on digital 20/21 and the second is next to AREF just like on the Leonardo.

There’s a 10-pin JTAG mini-header on the Due, debug pins and a second ICSP for the ATmega16U2 which takes care of USB. Speaking of USB – there’s two microUSB sockets. One is for regular programming via the Arduino IDE and the USB interface, the other is a direct native USB programming port direct to the SAM3X.

The SAM3X natively supports Ethernet, but this hasn’t been implemented on the hardware side for the Due. However some people in the Arduino forum might have a way around that.

Using the Due

First of all – at the time of writing – you need to install Arduino IDE v1.5.1 release 2 – a beta version. Windows users – don’t forget the USB drivers. As always, backup your existing installation and sketch files somewhere safe – and you can run more than one IDE on the same machine.

When it comes time to upload your sketches, plug the USB cable into the lower socket on the Due – and select Arduino Due (Programming Port) from the Tools>Board menu in the IDE.

Let’s upload a sketch now (download) – written by Steve Curd from the Arduino forum. It calculates Newton Approximation for pi using an infinite series. As you can see from the results below, the Due is much faster (690 ms) than the Mega2560 (5765 ms):

speedtest1part1

speedtest1part2

Next, let’s give the digital-to-analogue converters a test. Finally we have two, real, 12-bit DACs with the output pins being … DAC0 and DAC1. No more mucking about with external R-C filters to get some audio happening. These pins provides true analogue outputs which is controlled by the analogWrite() function. To use them is very simple – consider the following example sketch which creates a triangle wave:

And the results from the DSO:

dacdemo1 
This opens up all sorts of audio possibilities. With appropriate wavetable data saved in memory you could create various effects. However the DAC doesn’t give a full 0~3.3V output – instead it’s 1/6 to 5/6 of the Aref voltage. With the IDE there are example sketches that can play a .wav file from an SDcard – however I’d still be more inclined to use an external shield for that. Nevertheless for more information, have a look at the Audio library. Furthermore, take heed of the user experiences noted in the Arduino forum – it’s very easy to destroy your DAC outputs. In the future we look forward to experimenting further with the Due – so stay tuned.

Getting a Due

Good luck … at the time of writing – the Dues seem to be very thin on the ground. This may partly be due to the limited availability of the Atmel SAM3X8E. My contacts in various suppliers say volumes are quite limited.

Quality

I really hope this is a rare event, however one of the Dues received had the following fault in manufacturing:

One side of the crystal capacitor wasn’t in contact with the PCB. However this was a simple fix. How the QC people missed this … I don’t know. However I’ve seen a few Arduinos of various types, and this error is not indicative of the general quality of Arduino products.

Where to from here?

Visit the official Arduino Due page, the Due discussion section of the Arduino forum, and check out the reference guide for changes to functions that are affected by the different hardware.

Conclusion

Well that’s my first take on the Due – powerful and different. You will need to redesign existing projects, or build new projects around it. And a lot of stuff on the software side is still in beta. So review the Due forum before making any decisions. With that in mind – from a hardware perspective – it’s a great step-up from the Mega2560.

So if you’re interested – get one and take it for a spin, it won’t disappoint. The software will mature over time which will make life easier as well. If you have any questions (apart from Arduino vs. Raspberry Pi) leave a comment and we’ll look into it.

LEDborder

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, arm cortex, AT91SAM3X8E, dev-11589, due, part review, review, SAM3X8E, tutorial6 Comments

Kit Review – AVR ISP Shield

Introduction

In the last few weeks I needed to flash some ATmega328P microcontrollers with the Arduino bootloader. There are a few ways of doing this, and one method is to use an AVR ISP shield. It’s a simple kit to assemble and use, so let’s  have look at the process and results.

As the kit is manufactured by Sparkfun, it arrives in typical minimalist fashion:

The kit includes the following items:

That’s it – no URL to instructions or getting started guide or anything. Luckily we have a bit of knowledge behind us to understand what’s going on. The PCB has all the components as SMT including the status LEDs, so the only soldering required is the shield header pins and the six or ten-connector for the programming cable. You receive enough header pins to fit everything except for both six and ten – you can have one or the other, but not both. Having some handy I thought adding my own socket would be a good idea, however the pins are placed too closed to the group of six, nixing that idea:

Assembly

After collecting all my regular soldering tools and firing up the ‘888 it was time to get to work:

The first thing to fit were the shield headers. A simple way to do this is to break off the required lengths:

… then fit them to a matching board:

… then you place the shield on top and solder the pins. After that I used some of my own headers to fit both six and ten-pin ISP headers – it never hurts to do both, one day you might need them and not have soldering equipment at the ready. Finally the zero-insertion force (ZIF) socket goes in last. Push the lever down so it lays flat before soldering. Then you’re finished:

Operation

Now to program some raw microcontrollers. Insert the shield into your board. We used Arduino IDE v1.0.1 without modifying the original instructions from the Arduino team. Now upload the “ArduinoISP” sketch which is in the Examples menu. Once this has been successful the PLS LED will breathe. You then insert the microcontroller into the ZIF socket and gently pull the lever down. The notch on the microcontroller must be on the right-hand side when looking at the shield. Finally – check the voltage! There is a switch at the bottom-left of the shield that allows 5V or 3.3V. This only changes the Vcc so programming a 3.3V microcontroller will still involve 5V via SPI – possibly causing trouble.

Next  you need to select the target board for the microcontroller you’re programming. For example, if it’s going into a Uno – click Uno, even if you’re hosting the shield with an older board such as a Duemilanove. Next, choose the programmer type by selecting Tools > Programmer >  Arduino as ISP. Now for the magic – select Tools > Burn bootloader. The process takes around one minute, during which time the “PROG” LED on the shield will blink and flicker. It turns off once finished, and the IDE also notifies you of this. For the curious, the process is in the video below:

As you hopefully noticed earlier a cable is included which allows in-circuit programming from the shield to your existing project or prototype. However we didn’t have use for it at this time, it will come in handy when doing more advanced work later on.

Conclusion

It’s simple and it works. So if you need to flash a whole tube of raw micros with the Arduino bootloader, this is an option. Full-sized images available on flickr. This kit was purchased without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, avrisp, DEV-11168, kit review, review, tutorial4 Comments

Adventures with SMT and a POV SMT Kit

Introduction

There’s a lot of acronyms in the title for this article – what I wanted to say was “Adventures with surface-mount technology soldering with the Wayne & Layne Blinky Persistence-of-vision surface-mount technology reprogrammable light emitting diode kit…” No, seriously. Anyhow – after my last attempt at working with hand soldering surface-mount components couldn’t really be called a success, I was looking for something to start again with. After a little searching around I found the subject for today’s review and ordered it post-haste. Delivery from the US to Australia was twelve calendar days – which is pretty good, so you know the organisation is shipping quickly once you paid.

The kit is by “Wayne and Layne” which was founded by two computer engineering graduates. They have a range of open-source electronics kits that look like fun and a lot of “blinkyness”. Our POV kit is a simple persistence-of-vision display. By using eight LEDs in a row you can display words and basic characters by waving the thing through the air at speed, giving the illusion of a larger display. An analogy to this would be a dot-matrix printer that prints with ink which only lasts a fraction of a second. More on that later, first – putting it together.

Assembly

Like most other kits it arrived in an anti-static bag, with a label clearly telling you where the instructions are:

Upon opening the amount of items included seemed a little light:

However the instructions are detailed:

… and upon opening, reveal the rest of the components:

… which are taped down to their matching description on the cardboard. When cutting the tape to access the parts, do it slowly otherwise you might send them flying off somewhere on the bench and spend ten minutes looking for it. Finally, the PCB in more detail:

After reviewing the instructions, it was time to fire up my trusty Hakko and get started. At this point a few tools will come in handy, including SMT tweezers, some solder wick and a piece of blu-tac:

Following the instructions, and taking your time are the key to success. When mounting the two-pad components – put a blob of solder on one pad, then use tweezers to move the component in whilst keeping that pad of solder molten, remove the iron, then let go with the tweezers. Then the results should resemble capacitor C1 on the board as shown below:

Then a quick blob at the other end seals it in. This was easily repeated for the resistors. The next step was the pre-programmed PIC microcontroller. It is in the form of a SOIC package type, and required some delicate work. The first step was to stick it down with some blu-tac:

… then solder down one pin at each end. Doing so holds it in place and you can remove the blu-tac and solder the rest of the pins in. I couldn’t solder each pin individually, so dragged solder across the pins then tried to soak up the excess with solder wick. I didn’t find this too successful, so instead used the solder sucker to mop up the excess:

suckersmall

If you solder, you should get one of these – they’re indispensable. Moving forward, the PIC finally sat well and looked OK:

Next was the power-switch. It clicks neatly into the PCB making soldering very easy. Then the LEDs. They’re tiny and some may find it difficult to identify the anode and cathode. If you look at the top, there is a tiny dot closer to one end – that end is the cathode. For example, in the lineup:

Soldering in the LEDs wasn’t too bad – however to save time do all the anodes first, then the cathodes:

At this point all the tricky work is over. There are the light-sensor LEDs and the reset button for the top:

And the coin-cell battery holder for the bottom. The battery is also included with the kit:

Operation

Once you’ve put the battery in, turn it on and wave it about in front of yourself. There are some pre-programmed messages and symbols already loaded, which you can change with the button. However you’ll want to put your own messages into the POV – and the process for doing so is very clever. Visit the programming page, and follow the instructions. Basically you enter the text into the form, set the POV to programming mode – and hold it up against two squares on your monitor. The website will then blink the data which is received by the light-sensitive LEDs. Once completed, the POV will inform you of success or failure. This method of programming is much simpler than having to flash the microcontroller every time – well done Wayne and Layne. A pin and connector is also included which allows you to wear the blinky as a badge. Maybe at a hackerspace, but not in public.

Once programmed some fun can be had trying out various speeds of waving the blinky. For example, here it is with the speed not fast enough at all:

… and a little bit faster:

And finally with me running past the camera:

Furthermore, there is an ‘easter egg’ in the software, which is shown below:

Conclusion

We had a lot of fun with this simple little kit, and learned a thing or two about hand-soldering SMT. It can be done with components that aren’t too small – however doing so was an interesting challenge and the results were quite fun. So it met our needs very well. Anyone can do it with some patience and a clean soldering iron. You can order the Blinky POV SMT kit directly from Wayne & Layne. Full-sized images available on flickr. This kit was purchased without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in blinky pov, kit review, review, SMT, soldering, tutorial, wayne and layne1 Comment

Initial review: Aery32 Atmel AVR32 UC3A1 Development Board

Introduction

Recently (!) one of my readers sent me the subject of our review – the Aery32 development board from Finland. Based around the Atmel AVR32 UC3A1 128KB microcontroller – it is a painless way to get into AVR32 programming and development. Furthermore the hardware and software are completely open-source, so you can make your own and modify to your heart’s content. The specifications of the Atmel AVR32 UC3A1 show that it is an incredibly powerful microcontroller and they can be found in detail from Atmel here – plus you can download the data sheet from here.

[Update 13/06/2013 – now available in Australia from Little Bird Electronics]

Regular readers will know that I don’t work with this platform, so this review is written from the point of an absolute beginner. My apologies if some of the terminology used isn’t the norm. Moving forward, here is our Aery32 board:

… and the rear:

One could say that there is everything you need – and nothing you do not. Looking at the front of the board, apart from the MCU there is an LED for use, the mini-USB for programming and a switch for changing modes between the bootloader and program. On the rear are the pin references, and on the right-hand side solder pads (on both sides) for the JTAG debugger.  The following video is a short walkthrough:

Setup

The first thing to do is get the required software installed on the machine. Instructions for Windows, MacOS and Linux are provided. Here we have Windows 7 and the installation was simple – the Atmel software installed painlessly enough. You will also need the Aery32 software framework, which contains source files and compiling instructions for your projects. This is updated over time by the Aery32 project, so keep an eye on the github page.

After downloading the framework, keep an unaltered copy in a folder. Then you copy this and rename it for each new project. That is – for each project you start with a fresh framework folder and insert the code into the main.cpp file within the folder. Consider the following:

You can see how I have kept the framework in a folder to keep as a source, then made copies and renamed them for individual projects. Then inside each folder you have the various files – and the main.cpp which contains your project code.

Using the Aery32

From the beginning I was a little worried due to my lack of time and inexperience with AVR32 programming. However after determing how the software framework and code files are used as described earlier – the process of programming the board was easy. You then just need to learn how to program – a topic for another day… In the meanwhile, blinking the LED as a test was simple enough. After making a separate folder (see the image above) one simply edits the main.cpp file and adds the required code. For example – to blink the onboard LED:

Next, make sure the switch on the Aery32 is moved towards the reset button – this puts the board into bootloader mode. Plug in the USB cable, wait for recognition – then from the command prompt, navigate to the folder which contains the code and enter make program start. If all goes well you will see the following:

makeprogramstart

And if it doesn’t, the various errors are described as necessary. As you can see all the compilation and uploading is scripted for you making the whole process very simple. Then move the switch away from the reset button – which puts the board in run mode, then press reset. For anything further you’re going to need some external wiring – so for further experimenting purposes the first thing I did was solder in some standard 0.1″ dual inline header pins to allow easy access to a variety of I/O pins and GND. Although wanting to do more I’m pretty time-constrained at the moment so came up with not one but four blinking LEDs. Here’s the code:

and for the non-believers – the board in action:

Aery32-specific information and help is easy to find. For an open-source project, the documentation is extensive and includes many examples. Have a look around the documentation site to see what I mean. There is also a developer area which contains many articles about using the Aery32 and various examples within.

Conclusion

From my (beginner’s) perspective this board was very easy to setup and get working. Not having to worry about downloading hundreds of megabytes of IDE was great and allows programming from lightweight machines. And there is no doubt about the power or I/O features of the AVR32 UC3A1. Now I’ll get myself a good AVR32 book. So if you’re looking for a powerful and well-supported AVR32 development board, the Aery32 is a good start. You can order the board directly from the website at http://www.aery32.com/.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in aery32, atmel, avr32, review, tutorial, UC3A18 Comments

First Look – the Arduino Leonardo

Introduction

Recently the Arduino Leonardo was released, and I’ve finally got my hands on one. Some have claimed that the Leonardo as the successor to the Arduino Uno board, however that is somewhat subjective.  In this article we have a look for ourselves and examine the differences between the Uno boards that we’re used to and the new Leonardo.

The board

Here it is unwrapped from the cardboard packet:

It uses the same physical footprint as the Uno, so no surprises there:

 Now to travel around the board and see what’s new. First is the microcontroller – we have the Atmel ATmega32U4:

There are several pros and cons to using the 32U4. The pros include:

  • More analogue inputs. As well as the usual A0~A5, digital pins 4,6,8,9,10 and 12 can be configured as A6~A11
  • It handles USB. So no more external USB controller MCU or the old FTDI chip. Supposedly this saves money, however the retail price in some markets don’t reflect this
  • More PWM pins – well one more. They’re now on D3, 5, 6, 9, 10, 11 and 13
  • There is a little more SRAM than the Uno, it is now 2.5 kB
  • SPI has moved – they’re now wired to the ICSP pins. So you now have D10~D13 seperate to SPI
And the cons:
  • SPI has moved – they’re now wired to the ICSP pins. So if you have any shields that use SPI – too bad, they’re out. The most common example of this will be Ethernet shields – you’ll need to modify them with some jumper leads to contact the ICSP pins
  • I2C has moved over to D2+3. So if you have any shields using I2C – they’ll need to be modified
  • Less flash memory – the bootloader uses 4 kB of the 32 kB flash (the Uno used 0.5 kB)

However you can get an adaptor shield to use older Arduino shields with the Leonardo.

For MCU to Arduino pin mapping, see here. Next, for more on the USB side of things – as the 32U4 takes care of USB – take heed of the following notes from arduino.cc:

Since the Leonardo does not have a dedicated chip to handle serial communication, it means that the serial port is virtual— it’s a software routine, both on your operating system, and on the Leonardo itself. Just as your computer creates an instance of the serial port driver when you plug in any Arduino, the Leonardo creates a serial instance whenever it runs its bootloader. The Leonardo is an instance of USB’s Connected Device Class (CDC) driver.

This means that every time you reset the board, the Leonardo’s USB serial connection will be broken and re-established. The Leonardo will disappear from the list of serial ports, and the list will re-enumerate. Any program that has an open serial connection to the Leonardo will lose its connection. This is in contrast to the Arduino Uno, with which you can reset the main processor (the ATmega328P) without closing the USB connection (which is maintained by the secondaryATmega8U2 or ATmega16U2 processor).

There are some other changes to the board. Moving on, the next change is the USB socket. Do you recognise this socket?

Yes – micro USB. Thankfully (!) a growing number of mobile phones use this type for charging and USB connection, so you may already have a matching cable. Note that the Leonardo doesn’t include a cable, so if you’re an iPhone user – order yourself a cable with your Leonardo.

Next, the LEDs have been moved to the edge of the board. You can see them in the above image to the right of the USB socket. No more squinting through shields at strange angles to check the TX/RX lights. However this isn’t a new invention, our friends at Freetronics have been doing this for some time. Furthermore, the reset button has been moved to the corner for easier access.

There are also seperate connectors for the I2C bus – next to AREF, which should make modifying existing shields a little easier:

 Finally, due to the reduction in components and shift to SMD – there is what could almost be called a large waste of space on the board:

A few extra user LEDs wouldn’t have been a bad idea, or perhaps circuitry to support Li-Po rechargeable batteries. However the argument will be “that’s what a protoshield is for”. Just saying… As for the rest of the hardware, the specifications can be found here.

Finally, the Leonardo is available in two versions – with and without headers. This makes it easier to embed the Leonardo into fixed applications as you can directly solder to the various I/O pins. An alternative to this would instead be the Freetronics LeoStick, as it is much smaller yet fully compatible.

Software

First – you need to drag yourself into Arduino IDE v1.0.1. Note you can run more than one version of the IDE on the same machine if you don’t mind sharing the same preferences file. Next, the Leonardo doesn’t reset when you open the serial monitor window (from arduino.cc) –

That means you won’t see serial data that’s already been sent to the computer by the board, including, for example, most data sent in the setup() function. This change means that if you’re using any Serial print(), println() or write() statments in your setup, they won’t show up when you open the serial monitor. To work around this, you can check to see if the serial port is open like so:

Using the 32U4, you also have two serial ports. The first is the emulated one via the USB, and the second is the hardware UART on digital pins 0 and 1. Furthermore, the Leonardo can emulate a USB keyboard and mouse – however with a few caveats. There is a section on the Leonardo homepage that you should really read and take note of. But this emulation does sound interesting, and we look forward to developing some interesting tools to take use of them, so stay tuned.

Conclusion

There is nothing wrong with the Leonardo board, it works as described. However you could consider this a virtual “line in the sand”, or a new beginning. Due to the changes in the pinouts shields will need to be redesigned, and for those of you still programming in Arduino v23 – it’s time to get up to speed with v1.0.1. If you need the special USB functions, keyboard and/or mouse emulation, or are happy with the changes and can get one for less than the cost of a Uno – great.

Here’s a video from the main man Massimo Banzi:

However if you’re looking for your first Arduino board – this isn’t the board for you right now. There are too many incompatible shields out there, and the inability to cheaply replace the microcontroller will see some beginners burn out their first couple of boards rendering them useless. Get yourself an Arduino Uno or compatible board such as the Freetronics Eleven.

In conclusion, classifying the Leonardo board as good or bad is not a simple decision. It may or may not be an improvement – depending on your needs. Right now – for beginners, this is not the board for you. For those who understand the differences between a Uno and Leonardo, sure – no problem. Frankly, I would get a LeoStick instead.  At the end – it’s up to you to make an informed decision.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, atmega32u4, DEV-11286, leonardo, review, tronixstuff, tutorial23 Comments

Review: Agilent U1177A IR to Bluetooth Adaptor

In this review we examine the new Agilent U1177A infra-red to Bluetooth adaptor for the Agilent  U1272A DMM. You can also use the adaptor with the U1240-series DMMs with the optional adaptor. With some PC or Android device software you can monitor or log data from up to three DMMs. So let’s have a look and see what it’s all about.

Introduction

The adaptor arrives in a small box:

… with the following contents:

It was a relief to see the AAA cells included as we didn’t have any in stock. The yellow document is the China RoHS sheet, and the instructions are short but well detailed. The unit itself is quite small:

To fit the battery or reset the device, the front cover slides open revealing the innards to some degree:

and the rear:

The unit clips soundly to the rear of the DMM, however it does stick out quite a lot:

If you need to leave the meter unattended, you’ll need a level and vibration free surface, as the adaptor can be knocked out relatively easily from the top. The adaptor also blocks the hole at the back which some users may use with a hook or loop for positioning the DMM.

Software and Operation

You can use the U1177 with two platforms – Android and Windows, and we tested both. I’m sure if you have Mac Parallels, etc., that there may be some success there but I haven’t tested them. There are two applications available for Android devices – the mobile logger and mobile meter. You can download them both from the Google Play app – just search for ‘agilent‘, and the results should be

The third app is a game that is somewhat entertaining. We tried the applications on two Android devices – a HTC Velocity running Android 4.0.3 (which failed miserably, the software kept freezing) and a Motorola Xoom MZ601 with Android 3.2. I would say now that the software is marked “Beta” so caveat emptor. The data logging software worked on the Xoom but not the “Agilent Mobile Meter”. Moving forward, the logging software is quite good – you can display a graph, table or statistical value of the incoming data from up to three separate DMMs.

Below is a rough video of using the Xoom with data logging. We first make the Bluetooth connection, then measure resistance of a 1k ohm logarithmic pot, change the view to data table, then stop the logging and email the data. The app can email a .csv file which can be opened with any spreadsheet, etc. Using the app you can label each DMM feed to avoid confusion with the data files in the future.

Using the U1177A with a Windows 7 x64 machine was a lot more successful. You can download the Windows-based software from here (97 MB). After pairing the adaptor with the bluetooth connection software, the Agilent software loads but does not connect. You need to alter the data speed to 19200bps and select the COM port from the drop-down list in the “communication settings” on the left-hand side of the window, as shown below:

You can also use terminal software and AT commands to change the parameters of the U1177A, which is described in the user manual. Moving forward, once connected you can measure and log to your heart’s content. You can display a virtual meter:

8

Or choose a graphing display mode:

9

Note the short drop in value to zero as the graph increased on the far-right of the measurement in the image above. This occurs when the meter is changing range, just as the LCD will blink off then on due to the same phenomenon. Finally, you can also display the data as a table, for example:

10

Finally, you can export the data to a .csv file which can be opened with the usual spreadsheet or text editing software:

11

Using Windows OS Remote Multimeter Use Data Logging Other connection – hyperterminal etc. 

Conclusion

For data logging to a PC that is in Bluetooth range, the U1177A fits the bill. Although you can get a serial to IR cable (and early U1272A owners should have received one when the firmware update was released), the Bluetooth module will certainly be useful when moving around a worksite, or taking remote measurements from extreme temperature or NVH environments. The Android apps need to move out of beta stage – however due to the variety of devices and OS versions in the market this may be a long journey. However considering the price (~Au$52) it is inexpensive enough to keep around just-in-case.

Note – the U1177A was purchased by myself and reviewed without notice. Residing in Australia, ours was purchased from element14.com.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in agilent, android, bluetooth, multimeter, product review, review, test equipment, U1177A, U1272A2 Comments

Initial review: Hakko FX-888 Soldering Station

Introduction

During many years of orbiting around the world of electronics and related fields, soldering was not really one of my strong points. After moving more seriously into this field it occurred to me that my choice of soldering weapons played a part in the end results. So a few days ago I pulled the trigger and ordered my first “real” station – the Hakko FX-888.

Opening…

After waving goodbye to the courier and opening the delivery carton, the following was presented:

Frankly it’s only a box and shouldn’t matter, but you can appreciate the effort involved from a retail perspective. Opening up we find a neatly and safely packaged station with the multilingual instructions on top:

Everything is included to get going without any surprises. The station itself:

This is quite solid and weighty – at 1.3kg, so will not be moved by accident. The colours are quite snazzy and in some markets you can choose different colour schemes. According to Hakko – this is a “High-performance soldering iron that, in the pursuit both “usability” and “appearance”, has evolved beyond being a mere working tool”…

As you can see the temperature can be adjusted between 200 and 480 degrees Celsius. There is a calibration adjustment below the temperature knob, and the tool for calibration (“thermal correction”) is hidden away underneath the station:

You can also see the power switch on the right-hand side of the unit (when positioned normally). A tiny Allen key is included which is used to lock the temperature control to a desired position, however there isn’t a spot to keep it – so for now I have used (once again) some blu-tac to stick it under the base (not shown in photograph). Finally there is one red LED above the Hakko logo which lights when the heater is on – however it turns off once at the required temperature.

Next we have the soldering iron with fixed lead to the station:

This is a very light iron – for me the lightest so far, with a weight of 44 grams excluding the cord. The iron ships with a 0.5mm conical tip (type T18-B) that is fine for normal through-hole work, however there are sixteen different tips available from Hakko. What took me by surprise is the flexibility of the cord bushing, no matter which direction you turned the iron in your hand – there was hardly if any at all resistance from the cord. When changing tips be careful when unscrewing the nut, it is easy to unscrew the handle instead.

Finally we have the iron holder and parts:

The holder is made from metal, although it may not look so in the image. There is space for the included sponge and brass cleaning wire. You can also use the rubber cleaner (the grey/green lip) for cleaning as well. You can fit a large cleaning wire in the holder, however only small amount is presented at any one time, so you will need to rotate it now and again by opening the bottom of the holder which reveals the wire space.

Specifications

For those who like the numbers, here they are:

  • Station power consumption – 70W
  • Temperature range – 200~480 degrees Celsius
  • Temperature stability – +/- 1 degree Celsius at idle temperature
  • Iron power consumption – 65W at 26V AC
  • Cord length – 1.2m
  • Tip to ground resistance – 2Ω

The system is designed to protect against anti-static discharge, and the handle and other parts are conductors – not insulators. For more details please see the Hakko website.

Other observations

The reheating speed is excellent, the iron can reach any selected temperature in less than sixty seconds. This also helps avoid cold joints by recovering from temperature loss at a rapid rate. Furthermore having such a light iron without the burden of an AC lead at the back allows much more tip control and reduces wrist and muscle fatigue over long sessions.

Finally, the user manual includes exploded diagrams for all parts and the matching part numbers, which tells me Hakko want this station to last and are happy for you to maintain it yourself. Unlike using my older iron, I am sure with extended use the FX-888 will be less of a physical drain and also help improve my confidence in soldering.

Dave Jones from eevblog.com has described a modification to the FX-888 that allows an LED to show when the iron is on, not just heating. (Note that this voids your warranty):

Conclusion

Although the FX-888 is not inexpensive, it is very easy to use and light-years ahead of using a normal hand-held soldering iron. If you are finding yourself doing more soldering than the occasional hobbyist or are looking to work with a wide variety or components and soldering joints then you could do a lot worse than considering the FX-888. At this juncture it was not the cheapest, however I feel it was a solid investment and will last me a long time. And here it is, ready for work:

The Hakko FX-888 Soldering Station is available worldwide. Residing in Australia I purchased mine from element14.

Disclaimer – The items in this review were purchased by myself and reviewed without notifying the manufacturer or retailer. 

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in fx-888, hakko, review, soldering23 Comments

Is this the world’s smallest Arduino-compatible board?

Introducing the Freetronics LeoStick – one very small Arduino Leonardo-compatible** board, in the format of a typical USB memory stick – the board for integration into smaller projects, on-the-go fun when travelling, or minimalism-enthusiasts:

Whether or not the LeoStick is the world’s smallest Arduino-compatible board – it’s pretty darn tiny – for example:

Note that the length includes the USB plug extrusion on the PCB. A lot of small boards on the market may consider themselves to be fully Arduino-compatible, but with a few minor or major caveats – such as not having full USB interface, or using a cut-down MCU such as an ATtiny, or offer less current handling ability. After comparing their specifications with the LeoStick, you can see how much has gone into such a small board:

  • Native USB port built-in, no need for any USB or FTDI cables
  • Two Full Color RGB LEDs on-board! Drive different colored outputs and fun feedback from your sketch right away. One RGB LED is completely programmable, the other does Power, USB RX and TX indication, the RX and TX LEDs can also be controlled.
  • On-board Piezo speaker element, play sounds, tunes and beeps. Can also be used as a knock/vibration sensor
  • Same I/O pins. The LeoStick provides all the same header connections as larger boards, you can connect all the same sensors, actuators, and other inputs and outputs as typical Arduino models.
  • Breadboard compatible, has 0.1″ pitch pads and header pins can be fitted underneath
  • 500mA polyfuse and protection on the USB port
  • ATmega32U4 microcontroller, Arduino compatible with on-board USB, 32K Flash, 2.5K RAM, 1K EEPROM at 16MHz
  • ISP 6-pin connector for advanced programming of the ATmega32U4 MCU

Here is the underside of the LeoStick , showing the piezo speaker:

And here is a quick video of the LeoStick in action:

** Although this is a newly-released product, it does rely on a modified beta version of the upcoming Arduino Leonardo bootloader. There are some known issues with Windows 7 64-bit drivers and some library functions don’t work perfectly yet. Any firmware or Arduino Leonardo compatible support should not be considered to be final release firmware or in any way an official Arduino. At Freetronics’ request, please don’t hassle the Arduino team with support or requests related to this board – they’re solely the responsibility of Freetronics.

Nevertheless there is a growing and vibrant support forum where you can see examples of the LeoStick in action and discuss other subjects and issues. The LeoStick is also a very complete ATmega32U4 breakout and USB board by itself and the LeoStick can be programmed directly from the supplied standard ISP header by AVR Studio, Mac OSX-AVR, avrdude, WinAVR etc.

The LeoStick  is also new to us here as well, and we look forward to integrating it into projects in the near future, as well as having a board to experiment with when travelling. As we always say – if it meets your needs or you want to try something new, you could do a lot worse than getting yourself a LeoStickIf you are interested in learning how to use Arduino in general – check out our tutorial here. For more discussion and support information for the LeoStick consult the forum or product web page.

Disclaimer – The LeoStick board reviewed in this article was a promotional consideration made available by Freetronics

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, freetronics, leonardo, leostick, review

Review – Freetronics EtherMega

In this review we take a look at what is possibly the most fully-featured Arduino compatible board on the market today – the Freetronics EtherMega. This board combines the functionality of an Arduino Mega2560, a microSD card shield, and an Ethernet shield that supports power over Ethernet with optional 802.3af standard. So instead of having these three mashed together at a great expense:

thelot

… you can have this:

Freetronics EtherMega Tronixlabs Australia

Which saves space, time and money. Firstly, the specifications:

  • 100% compatible with the Arduino Mega2560. So you have the ATmega2560 microcontroller, 54 digital I/O pins with 14 PWM-capable, 256KB of flash memory, 8KB of SRAM and 4KB of EEPROM to play with, the Atmel 16u2 micrcontroller taking care of the USB interface;
  • However unlike the original, the EtherMega contains a switchmode power supply that allows operation from a DC power supply of between 7 and 28VDC without overheating;
  • Complete c0mpatibility with the Arduino Ethernet shield, using the Wiznet W5100 controller just like the original;
  • Network status LEDs on both the socket and the PCB;
  • Fixed SPI behaviour on Ethernet chipset;
  • Complete microSD card compatibility with SD library, and chip-select is on digital pin 4 so Ethernet and microSD can work together on the same sketch;
  • optional 802.3af power over Ethernet support at up to 48V using the optional regulator board which mounts on the EtherMega;
  • mini USB connector instead of the larger standard USB socket which can interfere with shields – and a USB cable is included

Furthermore there are a few modifications to make using the EtherMega easier or simpler. The first of these is the onboard prototyping area allowing you to add your own circuitry:

Also notice that the I2C pins have been brought out alongside the 5V and GND pins on the right. The only difference to take note of are the jumpers that are used to select either USB or DC socket power:

However that is a small price to pay compared to the convenience of the wide voltage-handling capability. Finally, unlike the original Arduino Mega2560 the designers have placed the TX/RX indicators at the top-left of the EtherMega so they are still visible when extra shields have been mounted:

The overall design and quality of the EtherMega is top notch, with a thick PCB, rounded corners, descriptive silk-screening, and packaging that can be reused as Mega or other part storage.

If you are looking for an Arduino Mega2560 and could use Ethernet, power-over-Ethernet, a microSD card interface and full, 100% Arduino compatibility you could do a lot worse than getting yourself an EtherMega. If you are interested in learning how to use Arduino and Ethernet – check out our tutorial here. Or to get your Arduino tweeting, visit here.

And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a fourth printing!) “Arduino Workshop”.

visit tronixlabs.com

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

Posted in 802.3af, arduino, ethermega, ethernet, freetronics, review, shield, tronixlabs0 Comments

Subscribe via email

Receive notifications of new posts by email.

The Arduino Book

Arduino Workshop

Für unsere deutschen Freunde

Dla naszych polskich przyjaciół ...

Australian Electronics!

Buy and support Silicon Chip - Australia's only Electronics Magazine.

Use of our content…

%d bloggers like this: