Tag Archives: 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.

Review – Nextion TFT Human Machine Interface

Introduction

Using a large TFT LCD with various development boards can often be a trial – from dedicating eight or more GPIO pins to working with a flaky software library or memory limitations. Personally I have thought “there must be a better way”, and thus usually results in shifting the concept over to a single-board computer such as a Raspberry Pi to get the job done.

However this is no longer necessary – thanks to the team at Itead Studio and now available from Tronixlabs. They have developed a series of TFT LCDs which include enough onboard hardware, a graphic processor unit and memory to be a self-contained display solution whose output can be created with a WYSIWYG editor and be controlled using simple serial text commands.

For a quick demonstration, check out the following video:

As you can see the display can be quite complex, and with some imagination you can create a neat interface for your project. And once the interface has been uploaded to the display, all your development board needs to do is communicate with the Nextion displays via a TTL-level USART  (serial port).

Hardware

Nextion displays are available in a wide range from 2.4″ through to 7″ at varying resolutions – with all having a resistive touch screen:

Itead Nextion displays

On the rear of an example 4.3″ unit we can see the brains behind the Nextion – an STM32F microcontroller, 16MB of flash memory and a meaty Altera MAXII FPGA. :

Itead Nextion large rear

… and the 2.4″ version which has 4MB of flash memory:

Itead Nextion small rear

And as shown above you can see from the images there is a microSD card socket on each display, and the only external connections are 5V and GND plus TX/RX for serial data to your system. For testing purposes with a Windows-based PC you can use a simple USB-TTL serial cable. This could also be used for a more permanent solution between a Raspberry Pi, or any USB-enabled PC.

Software

The display interface is created used an IDE (integrated development environment) which is currently available for Windows. Using the IDE, you can import images for use in the interface, determine touch areas, add  buttons, progress bars, gauges and much more.

Nextioneditor

Furthermore there is a simulator and debugger tool which allows you to test your interface on the PC or directly to the Nextion unit. The simulator also allows for sending and receiving commands with the display so you can quickly test your code.

The simulator is also a demonstration of how the Nextion can be controlled via USB-TTL serial cable from a PC, thus great for secondary displays via processing, python etc – or from any software that can communicate via the PC’s serial port. And much cheaper than a secondary display if you only want to display certain types of data.

To create an interface is easy, you first start with a background image or a solid colour. Then you can add objects such as buttons for user-input, or define an area of the screen to a “touch-zone” – which, when pressed, will send a value out to the connected device. You can also add text zones, which will display incoming text from the connected device – along with progress bars and gauges.

For an ideal example of all this together, watch the following video:

 

Conclusion

Although the units I had for test were prototype review units supplied by Itead, they worked as expected and really do solve the problem of creating a contemporary user-interface without typing up microcontroller resources. Nextion displays are now available from our Tronixlabs store.

And finally a plug for my own store – tronixlabs.com – offering a growing range and Australia’s best value for supported hobbyist electronics from adafruit, DFRobot, Freetronics, Seeed Studio 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.

Project Review – Silicon Chip Capacitance Substitution Box

Introduction

Every month Australian electronics magazine Silicon Chip publishes a variety of projects, and in some cases various (well … one of two) electronics retailers will pick up the project and offer it as a kit. However for an increasing number of new projects they don’t, which leaves the interested reader with one option – build the entire project from scratch.

But thankfully this is no longer the case – as the team from Silicon Chip now offer a range of project PCBs and matching front panels for sale directly from their website. Although buying these parts is not the cheapest option, it gives the busy person who likes making things a quick start – or the inexperienced more opportunities to complete a successful project.

So as a test of this new service, I bought the PCB and front panel for the Capacitance Substitution Box project described by Nicholas Vinen in the Juily 2012 issue of SC:

capacitance_article

This is something I’ve meant to make for a while – but didn’t really have the inclination to make one from scratch, so it was neat to see a version published in the magazine. I believe the subjects in the magazine article are oftern prototypes, which explains the difference in colour for the front panel.

The parts arrived in a week after placing the order, and are of a high quality:

capacitance box panel

capacitance pcb front

capacitance pcb rear

When complete, the capacitance substitution box PCB and panel will fit nicely into an Altronics H0151 enclosure, so you don’t need to do any drilling or filing. The next task was to organise the required parts. The rotary switches, terminal posts and the usual odds and ends can be found at Altronics, Jaycar or other suppliers. However the main components – the capacitors – offered two options.

The first option is to simply use capacitors from personal stock or the stores. However the tolerance of these parts can vary wildly, with up to twenty percent either way. This is ok for simple uses, however when values are combined – the tolerance of larger values can negate the lower values completely. So instead I’ve chosen the second option – which involves using brand-name low-tolerance capacitors.

Thus I turned to element14 who stock not only a huge range of not only regular but also the low-tolerance capacitors, and can also have them on my desk usually by the next working day. Finally, it’s nice to have all the parts arrive in little bags… neatly organised ready to go:

capacitors

It’s easy to search for low-tolerance parts with element14, as the automatic filtering has tolerance as a parameter:

element14 capacitors

Furthermore you can also ensure you have the voltage rating of at least 50V DC as well. So after half an hour the capacitor order was completed and arrived when expected – using parts from Panasonic, Vishay, and Wima. The tolerances of our capacitors used varied between one and ten percent, which will help improve the accuracy of the substitution box.

Assembly

The PCB has the capacitor values labelled neatly on the silk-screen, so soldering in all the capacitors was a relatively simple but long operation. Having them arrive in separate packets made life a lot easier. During the soldering process it’s a good idea to have a  break or two, which helps you avoid fatigue and making any mistakes.

capacitance substitution box half finished

There may be a few capacitors that are a little too wide to fit with the others, so they can be mounted on the other side of the PCB:

capacitance substitution box wide capacitor

However they all end up fitting well:

capacitance substitution box half finished

The next step was to configure the first rotary switch for six position use, then cut the plastic stopped from the side of each rotary switch. In the following image you have a before and after example:

capacitance substitution box rotary switches

Now the rotary switches can have their shafts trimmed and then be soldered onto the PCB:

capacitance substitution box switches trimmed

However ensure you have the first rotary switch in the right way – that is the selections are selected across the top half, not the bottom. Remove the nuts from the rotary switches, and double-check all the capacitors are fitted, as once the next step is completed … going back will be difficult to say the least.

At this point the banana sockets can be fitted to the panel, and then soldered into place, and then you’re finished. Just place the panel/PCB combination inside the box and screw it down:

capacitance substitution box complete

Using the Capacitance Substitution Box

Does it work? Yes – however you don’t get exact values, there will always be a tolerance due to the original tolerance of the capacitors used and the stray capacitance of the wires between the box and the circuit (or capacitance meter). Nevertheless our example was quite successful. You can see the box in action with our Altronics LC meter kit in this video.

Again, using the best tolerance capacitors you can afford will increase the accuracy of this project.

Conclusion

Over time this would be a useful piece of equipment to have – so if your experiments or projects require varying capacitor value, this project will serve the purpose nicely. Plus it helps with mental arithmetic and measures of capacitance! Please do not ask me for copies of the entire Silicon Chip article, refusal may offend. Instead – visit their website for a reprint or digital access.

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.

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]

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.

Easily test and experiment with GSM modules using AT Command Tester

Introduction

Working with GSM modules and by extension Arduino GSM shields can either be a lot of fun or bring on a migraine. This is usually due to the quality of module, conditions placed on the end user by the network, reception, power supply and more.

Furthermore we have learned after several years that even after following our detailed and tested tutorials, people are having trouble understanding why their GSM shield isn’t behaving. With this in mind we’re very happy to have learned about a free online tool that can be used to test almost every parameter of a GSM module with ease – AT Command Tester. This software is a Java application that runs in a web browser, and communicates with a GSM module via an available serial port.

Initial Setup

It’s simple, just visit http://m2msupport.net/m2msupport/module-tester/ with any web browser that can run Java. You may need to alter the Java security settings down to medium. Windows users can find this in Control Panel> All Control Panel Items  > Java – for example:

Java security settings

Once the security settings have been changed, just visit the URL, click ‘accept’ and ‘run’ in the next dialogue box that will appear, for example:

run Java app

And after a moment, the software will appear:

at command tester

Once you’re able to run the AT Command Tester software, the next step is to physically connect the hardware. If you’re just using a bare GSM module, a USB-serial adaptor can be used for easy connection to the PC. For Arduino GSM shield users, you can use the Arduino as a bridge between the shield and PC, however if your GSM shield uses pins other than D0/D1 for serial data transmission (such as our SIM900 shield) then you’ll need to upload a small sketch to bridge the software and hardware serial ports, for example:

Using the software

Once you have the hardware connected and the Arduino running the required sketch, run the software – then click “Find ports” to select the requried COM: port, set the correct data speed and click “Connect”. After a moment the software will interrogate the GSM module and report its findings in the yellow log area:

at command tester connected

 As you can see on the left of the image above, there is a plethora of options and functions you can run on the module. By selecting the manufacturer of your GSM module form the list, a more appropriate set of functions for your module is displayed.

When you click a function, the AT command sent to the module and its response is shown in the log window – and thus the magic of this software. You can simply throw any command at the module and await the response, much easier than looking up the commands and fighting with terminal software. You can also send AT commands in batches, experiment with GPRS data, FTP, and the GPS if your module has one.

To give you a quick overview of what is possible, we’ve made this video which captures us running a few commands on a SIM900-based Arduino shield. If possible, view it in 720p.

Conclusion

Kudos to the people from the M2Msupport website for bringing us this great (and free) tool. It works – so we’re happy to recommend it. 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.

Kit Review – Altronics/Silicon Chip ISD2590 Digital Message Recorder

Introduction

Every month Australian electronics magazine Silicon Chip publishes a variety of projects, and in February 1994 they published the “90 Second Digital Message Recorder” project. That was a long time ago, however you can still find the kit today at Altronics (and at the time of writing, on sale for AU$26), and thus the subject of our review.

The kit offers a simple method of recording and playing back 90 seconds of audio, captured with an electret microphone. When mounted in a suitable enclosure it will make a neat way of leaving messages or instructions for others at home.

Assembly

The kit arrives in typical Altronics fashion:

Altronics K9570 90 second message recorder kit package

… and includes everything required including IC sockets for the ISD2590 and the audio amplifier:

Altronics K9570 90 second message recorder kit inclusions

Altronics K9570 90 second message recorder kit components

The PCB missed out on silk-screening – which is a pity:

Altronics K9570 90 second message recorder kit instructions PCB front

however it is from an original design from twenty years ago. The solder mask is neat and helps prevent against lazy soldering mistakes:

Altronics K9570 90 second message recorder kit PCB back

Finally the detailed instructions including component layout and the handy Altronics reference guide are also included. After checking and ordering the resistors, they were installed first along with the links:

Altronics K9570 90 second message recorder kit construction

 If you have your own kit, there is a small error in the instructions. The resistor between the 2k2 and the 10uF electrolytic at the top of the board is 10k0 not 2k2. Moving on, these followed by the capacitors and other low-profile components:

Altronics K9570 90 second message recorder kit construction 4

The rest of the components went in without any fuss, and frankly it’s a very easy kit to assemble:

Altronics K9570 90 second message recorder kit finished

 The required power supply is 6V, and a power switch and 4 x AA cell holder is included however were omitted for the review.

How it works

Instead of some fancy microcontrollers, the kit uses an ISD2590P single chip voice recording and playback IC:

Altronics K9570 90 second message recorder kit ISD2590

It’s a neat part that takes care of most of the required functions including microphone preamp, automatic gain control, and an EEPROM to store the analogue voltage levels that make up the voice sample. The ISD2590 samples audio at 5.3 kHz which isn’t CD quality, but enough for its intended purpose.

Apart from some passive components for power filtering, controls and a speaker amplifier there isn’t much else to say. Download the ISD2590 data sheet (pdf), which is incredibly detailed including some example circuits.

Operation

Once you apply power it’s a simple matter of setting the toggle switch on the PCB down for record, or up for playback. You can record in more than one session, and each session is recorded in order until the memory is full. Then the sounds can be played back without any fuss.

The kit is supplied with the generic 0.25W speaker which is perhaps a little weak for the amplifier circuit in the kit, however by turning down the volume a little the sound is adequate. In this video you can see (and hear) a quick recording and playback session.

Conclusion

This kit could be the base for convenient message system – and much more interesting than just scribbling notes for each other. Or you could built it into a toy and have it play various tunes or speech to amuse children. And for the price it’s great value to experiment with an ISD2590 – just use an IC socket. Or just have some fun  – we did.  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.

Old Kit Review – Talking Electronics Fluorescent Simulator

Introduction

Slowly we’re working through the stock of old kits, and in this article we have the “Fluorescent Lamp” simulator from Talking Electronics. To save repeating myself you can read more about Talking Electronics here and watch interviews of the founder Colin Mitchell here.

So why would you want to simulate a fluoro’ tube anyway? Model railways! When your model world moves from day to night, it’s neat to have street lights and so on “flicker” on just like the real thing. And thus you can create this effect as well. It can drive incandescent lamps up to 12V, and allowing it to be powered easily from most layouts.

The kit was originally described in the Talking Electronics book “Electronics for Model Railways” (volume 1) which was full of useful and interesting electronics to liven up any layout. The book may now out of print however at the time of writing this you can download or view most of the projects from the index column of the Talking Electronics website… or contact Talking Electronics if they have any copies of the book (or kit) to sell.

Assembly

Time was not kind to the kit, to be frank it was surprising to find one at all:

Talking Electronics Fluorescent Simulator kit

(Just a note for any over-enthusiastic readers, Talking Electronics is no longer at the address on the bag shown above). However it was complete and ready for assembly. The PCB has a silk-screen with the required component placement information, polarities and so on – a first for the time:

Talking Electronics Fluorescent Simulator PCB top

Talking Electronics Fluorescent Simulator PCB bottom

The instructions and “how it works” are not included with the kit as you were meant to have the book, however TE have made them available as a separate download (.pdf) The kit included everything required to get started, and there’s an LED which replicates the effect so you can test the board without having to watch the connected bulb (which may be a distance away). Finally an IC socket is included 🙂

Talking Electronics Fluorescent Simulator parts

The actual assembly process was very straight forward, which simply required starting with the low-profile components and working up to the large ones:

Talking Electronics Fluorescent Simulator assembly 1

The only problem with the PCB was the holes – looks like only one drill size had been used (apart from the mounting holes) which made getting that rectifier diode in a little tricky. Otherwise it was smooth sailing.

Talking Electronics Fluorescent Simulator finished 2

Not having a model railway at the moment left me with the simple example of the onboard LED and a small incandescent globe to try with the circuit. You can see the kit working in this video.

John – Why do you publish these “Old Kit Reviews”?

They’re more of  a selfish article, like many electronics enthusiasts I have enjoyed kits for decades – and finding kits from days gone by is a treat. From various feedback some of you are enjoying them, so they will continue for fun and some nostalgia. If you’re not interested, just ignore the posts starting with “Old”!

Conclusion

For a kit from the mid-1980s, this would have solved the problem neatly for model railway enthusiasts. By using two or more of the kits with different capacitor values, many model lights could blink on with seemingly random patterns. However it’s 2014 so you could use a PIC10F200 or ATtiny45 and reduce the board space and increase the blinking potential.

Nevertheless, it was an interesting example of what’s possible with a digital logic IC. Full-sized images and a lot more information about the kit 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.

Old Kit Review – Silicon Chip Transistor Beta Tester

Introduction

After exploring a quiet , dusty electronics store in the depths of suburbia the other week, I came across this kit from Altronics (K2534) which is the subject of this review. The Transistor Beta tester is the second revision of a tester designed by John Clarke for the March 1991 issue of Silicon Chip magazine, and promises to offer a simple way of measuring the gain of almost any NPN or PNP bipolar transistor. But first some public answers to recent feedback…

John – Why do you publish these “Old Kit Reviews”?

They’re more of  a selfish article, like many electronics enthusiasts I’ve enjoyed kits for decades – and finding kits from days gone by is a treat. From various feedback some of you are enjoying them, so I’ll continue with them for fun and some nostalgia. If you’re not interested, just ignore the posts starting with “Old”!

Where’s the schematic?

After publishing a few kit reviews, people have been asking me for the schematics. For kits that are based on magazine articles from Silicon Chip and the like, the details are Copyright and I can’t legitimately give you a copy. You need to contact the magazine or kit supplier. The surviving electronics magazines often run “on the smell of an oily rag” so in order to support them I promote the idea of paying for copies which are obtainable from the magazine. Plus Australia is a small country, where people in this industry know each other through first or second connections – so I don’t want to annoy the wrong people. However Google is an awesome tool,  and if you want to make your own beta tester there are many example circuits to be found – so have fun.

Back to the review – what is “beta”?

Apart from a letter of the Greek alphabet and a totally-underrated form of VCR format, beta is a term used to define the amount of gain of a transistor. From the guide:

Silicon Chip transistor beta tester what is beta

Assembly

Here’s our kit from 1991, rescued from the darkness of the store:

Silicon Chip transistor beta tester packaging

Which contained the nice box, plus all the required components except for an IC socket, and a few screws and mounting nuts that should have been included. The instructions looked to be a photocopy of a photocopy, harking back to the 1980s…

Silicon Chip transistor beta tester contents

Silicon Chip transistor beta tester components

Looks like an off-brand 555 has been used (or substituted), however a bit of research indicated that it is most likely from LG Semiconductor:

Silicon Chip transistor beta tester off brand 555

The PCB was made to the usual standard at the time, just drilled:

Silicon Chip transistor beta tester PCB rear

Silicon Chip transistor beta tester PCB front

The front panel was well done, and kindly pre-drilled by a previous customer. The kit came with a 3mm LED however this mystery person had drilled the hole out for a 5mm:

Silicon Chip transistor beta tester front panel

… but hadn’t cut the oblong for the slide switch wide enough. But the biggest problem was that the PCB was just a smidge too wide for the included enclosure:

Silicon Chip transistor beta tester PCB not fitting

Nevertheless it was time to get started, and the resistors were measured, lined up and fitted:

Silicon Chip transistor beta tester resistors lined up

Then the rest of the components fitted as normal, however they need to stay below the horizontal level of the slide switch bezel:

Silicon Chip transistor beta tester assembly 1

… which was somewhat successful. Then to fit the potentiometer, battery snap …

Silicon Chip transistor beta tester assembly 2

and the test leads:

Silicon Chip transistor beta tester assembly 3

 And we’re finished:

Silicon Chip transistor beta tester finished

How it works

Operation is quite simple, just wire up the test leads to the transistor’s base, collector and emitter – set the PNP/NPN switch and press test. Then you turn the knob until the LED just turns on – at which point the scale indicates the gain.

“Modern-day” replacements

Digital technology has taken over with this regard, and a device such as the one below can not only give the gain, but also the component details, identify legs, and much more:

Silicon Chip transistor beta tester modern tester gain

I’ll be sticking with this one for the time being. Jaycar have discontinued the analyser shown above, but Altronics have the “Peak” unit which looks even more useful.

Conclusion

Well… that was fun. A lot of promise, however with a few details not taken care of the kit was just a bit off. Considering this was around twenty years old and possibly shop-soiled I can’t complain. For the record the good people at Altronics have a great line of kits. Full-sized images and a lot more information about the kit are available on flickr.

And while you’re here – are you interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press.

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.

Kit Review – “Short Circuits” 3 Digit Counter

Introduction

Time for another kit review and in this instalment we have a look at the “3 digit counter” kit from Tronixlabs. This is part of a much larger series of kits that are described in a three volume set of educational books titled “Short Circuits”.

Aimed at the younger readers or anyone who has an interest in learning electronics, these books (available from Tronixlabs) are well written and with some study and practice the reader will make a large variety of projects and learn quite a bit. They could be considered as a worthy 21st-century replacement to the old Dick Smith “Funway…” guides.

The purpose of this kit is to give you a device which can count upwards between zero and 999 – which can be used for various purposes and also of course to learn about digital electronics.

Assembly

The kit arrives in typical retail fashion:

Jaycar Short Circuits Counter Kit packaging

Everything you need to make the counter is included except for the instructions – which are found in the “Short Circuits” volume two book – and IC sockets. Kits for beginners with should come with IC sockets.

Jaycar Short Circuits Counter Kit contents

The components are separated neatly in the bag above, and it was interesting to see the use of zero ohm resistors for the two links on the board:

KJ8234 Jaycar Short Circuits Counter Kit components

The PCB is excellent. The silk screening and solder-mask is very well done.

KJ8234 Jaycar Short Circuits Counter Kit PCB top

Jaycar Short Circuits Counter Kit PCB bottom KJ8234

Furthermore I was really, really impressed with the level of detail with the drilling. The designer has allowed for components with different pin spacing – for example the 100 nF capacitor and transistors as shown below:

Jaycar Short Circuits Counter Kit PCB detail KJ8234

The instructions in the book are very clear and are written in an approachable fashion:

Jaycar Short Circuits Counter Kit instructions KJ8234

Jaycar Short Circuits Counter Kit instructions two KJ8234

There’s also a detailed explanation on how the circuit works, some interesting BCD to decimal notes, examples of use (slot cars!) and a neat diagram showing how to mount the kit in a box using various parts from Jaycar – so you’re not left on your own.

Construction went well, starting with the low-profile parts:

Jaycar Short Circuits Counter Kit assembly 1 KJ8234

… then the semiconductors:

Jaycar Short Circuits Counter Kit assembly 2 KJ8234

… then the higher-profile parts and we’re finished:

Jaycar Short Circuits Counter Kit assembly finished KJ8234

There wasn’t any difficulty at all, and the counter worked first time. Although I’m not a new user, the quality of PCB and instructions would have been a contributing factor to the success of the kit.

How it works

The input signal for the counter (in this case a button controlling current from the supply rail) is “squared-up” by an MC14093 schmitt-trigger IC, which then feeds a MC14553 BCD counter IC, which counts and then feeds the results to a 4511 BCD to 7-segment converter to drive the LED digits which are multiplexed by the MC14553. For the schematic and details please refer to the book. Operation is simple, and demonstrated in the following video:

However you can feed the counter an external signal, by simply applying it to the input section of the circuit. After a quick modification:

Jaycar Short Circuits Counter Kit counter input KJ8234

… it was ready to be connected to a function generator. In the following video we send pulses with a varying frequency up to 2 kHz:

Conclusion

This is a neat kit, works well and with the accompanying book makes a good explanation of a popular digital electronics subject. There aren’t many good “electronics for beginners” books on the market any more, however the “Short Circuits” range fit the bill.

And finally a plug for our own store – tronixlabs.com – which along with being Australia’s #1 Adafruit distributor, also offers a growing range and Australia’s best value for supported hobbyist electronics from Altronics, Jaycar, DFRobot, Freetronics, 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.

Tutorial – Send email with the Arduino Yún

Introduction

This is the third in a series of tutorials examining various uses of the Arduino Yún. In this article we’ll examine how your Arduino Yún can send email from a Google email account. Doing so gives you a neat and simple method of sending data captured by the Arduino Yún or other notifications.

Getting Started

If you haven’t already done so, ensure your Arduino Yún can connect to your network via WiFi or cable – and get a Temboo account (we run through this here). And you need (at the time of writing) IDE version 1.5.4 which can be downloaded from the Arduino website.

Finally, you will need a Google account to send email from, so if you don’t have one – sign up here. You might want to give your Arduino Yún an email address of its very own.

Arduino Yun Yún front

Testing the Arduino Yún-Gmail connection

In this first example we’ll run through the sketch provided by Temboo so you can confirm everything works as it should. This will send a simple email from your Arduino Yún to another email address. First, copy the following sketch into the IDE but don’t upload it yet:

Before uploading you need to enter five parameters – the email address to send the email with, the password for that account, the recipient’s email address, and the email’s subject line and content. These can be found in the following lines in the sketch – for example:

So enter the required data in the fields above. If you’re sending from a Google Apps account instead of a Gmail account – that’s ok, just enter in the sending email address as normal. Temboo and Google will take care of the rest.

Finally, create your header file by copying the the header file data from here (after logging to Temboo) into a text file and saving it with the name TembooAccount.h in the same folder as your sketch from above. You know this has been successful when opening the sketch, as you will see the header file in a second tab, for example:

arduino yun temboo header file

Now you can upload the sketch, and after a few moments check the recipient’s email account. If all goes well you will be informed by the IDE serial monitor as well (if your Yún is connected via USB). It’s satisfying to see an email come from your Arduino Yún, for example in this short video.

If your email is not coming through, connect your Arduino Yún via USB (if not already done so) and open the serial monitor. It will let you know if there’s a problem in relatively plain English – for example:

Error
A Step Error has occurred: “An SMTP error has occurred. Make sure that your credentials are correct and that you’ve provided a fully qualified Gmail
username (e.g., [email protected]) for the Username input. When using Google 2-Step Verification, make sure to
provide an application-specific password. If this problem persists, Google may be restricting access to your account, and you’ll need to
explicitly allow access via gmail.com.”. The error occurred in the Stop (Authentication error) step.
HTTP_CODE
500


So if this happens, check your email account details in the sketch, and try again.

Sending email with customisable subject and content data

The example sketch above is fine if you want to send a fixed message. However what if you need to send some data? That can be easily done. For our example we’ll generate some random numbers, and integrate them into the email subject line and content. This will give you the framework to add your own sensor data to emails from your Arduino Yún. Consider the following sketch:

Review the first section at the start of void loop(). We have generated two random numbers, and then appended some text and the numbers into two Strings – emailContent and emailSubject.

These are then inserted into the SendEmailChoreo.addInput lines to be the email subject and content. With a little effort you can make a neat email notification, such as shown in this video and the following image from a mobile phone:

arduino yun email demonstration

Conclusion

It’s no secret that the Yún isn’t the cheapest development board around, however the ease of use as demonstrated in this tutorial shows that the time saved in setup and application is more than worth the purchase price of the board and extra Temboo credits if required.

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.

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.

Old Kit Review – Silicon Chip Mini Stereo Amplifier

Introduction

In this review of an older kit we examine the aptly-named “Mini Stereo Amplifier” from Dick Smith Electronics (catalogue number K5008), based on the article published in the October 1992 issue of Silicon Chip magazine.

The purpose of the kit is to offer a stereo 1W+1W RMS amplifier for use with portable audio devices that only used headphones, such as the typical portable tape players or newly available portable CD players. I feel old just writing that. At the time it would have been quite a useful kit, paired with some inexpensive speakers the end user would have a neat and portable sound solution. So let’s get started.

Assembly

Larger kits like this one that couldn’t be retailed on hanger cards shipped in corrugated cardboard boxes that were glued shut. They looked good but as soon as a sneaky customer tore one open “to have a look” it was ruined and hard to sell:

Dick Smith Electronics K5008 Stereo Amplifier Kit box

The amplifier kit was from the time when DSE still cared about kits, so you received the sixteen page “Guide to Kit Construction” plus the kit instructions, nasty red disclaimer sheet, feedback card, plus all the required components and the obligatory coil of solder that was usually rubbish:

Dick Smith Electronics K5008 Stereo Amplifier Kit all contents

However the completeness of the kit is outstanding, everything is included for completion including an enclosure and handy front panel sticker:

Dick Smith Electronics K5008 Stereo Amplifier Kit enclosure face sticker

… all the sockets, plenty of jumper wire and even the rubber feet:

Dick Smith Electronics K5008 Stereo Amplifier Kit components

The PCB is from the old-school of design – without any silk-screening or solder mask:

Dick Smith Electronics K5008 Stereo Amplifier Kit PCB front

Dick Smith Electronics K5008 Stereo Amplifier Kit PCB rear

However the instructions are quite clear so you can figure out the component placement easily. Which brings us to that point – all the components went in with ease:

Dick Smith Electronics K5008 Stereo Amplifier Kit PCB partial assembly

… then it was a matter of wiring in the sockets, volume potentiometer and power switch:

Dick Smith Electronics K5008 Stereo Amplifier Kit socket wiring

Instead of using a 3.5mm phono socket for power input, I used a 9V battery snap instead. The amplifier can run on voltages down to 1.8V so it will do for the limited use I have in mind for the amplifier. However in the excitement of assembly I forgot the power switch:

Dick Smith Electronics K5008 Stereo Amplifier Kit PCB forgot the switch

However it wasn’t any effort to rectify that. You will also notice three links on the PCB, which I fitted instead of making coils (more on this later). So at that point the soldering work is finished:

Dick Smith Electronics K5008 Stereo Amplifier Kit PCB finished

Now to drill out the holes on the faceplate. Instead of tapering out the slots on the side of the housing, I just drilled all the holes on the front panel:

Dick Smith Electronics K5008 Stereo Amplifier Kit panel

Turns out the adhesive on the front panel sticker had lost its mojo, so I might head off and get some white-on-black tape for the label maker. However in the meanwhile we have one finished mini stereo amplifier, which reminds me of an old grade seven electronics project:

Dick Smith Electronics K5008 Stereo Amplifier Kit finished

How it works

The amplifier is based on the STMicro TDA2822M (data sheet .pdf) dual low-voltage amplifier IC. In fact the circuit is a slight modification of the stereo example in the data sheet. As mentioned earlier, the benefit of this IC is that it can operate on voltates down to 1.8V, however to reach the maximum power output of 1W per channel into 8Ω loads you need a 9V supply. The output will drop to around 300 mW at 6V.

Finally the Silicon Chip design calls for a triplet of coils, one each on the stereo input wires – used to prevent the RF signal being “shunted away” from the amplifier inputs. The idea behind that was some portable radios used the headphones as an antenna, however we’ll use it with the audio out from a mobile phone so it was easier to skip hand-winding the coils and just put links in the PCB.

Using the Amplifier

The purpose of this kit was to have some sound while working in the garage, so I’ve fitted a pair of cheap 1W 8Ω speakers each to a length of wire and a 3.5mm plug as shown in the image above. And for that purpose, it works very well. In hindsight it turns out the speakers were rated at 1W peak not RMS, however they still sound great.

Conclusion

Another kit review over. This is a genuinely useful kit and a real shame you can’t buy one today. And again – to those who have been asking me privately, no I don’t have a secret line to some underground warehouse of old kits – just keep an eye out on ebay as they pop up now and again. Full-sized images and much more information about the kit are available 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.