Archive | arduino

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 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 IDE (which can co-exist with the 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 team about the Arduino M0 Pro ask in their support forum.

Finally, check out – 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.


As always, have fun and keep checking into 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

Control your Arduino over the Internet using Blynk


There are many ways of remotely-controlling your Arduino or compatible hardware over the Internet. Some are more complex than others, which can be a good thing or a bad thing depending on your level of expertise. Lately we’ve become more interested in this topic and have come across Blynk, which appeared to be a simple solution – and thus the topic of our review.

What is Blynk?

From their website: “Blynk is a Platform with iOS and Android apps to control Arduino, Raspberry Pi and the likes over the Internet. It’s a digital dashboard where you can build a graphic interface for your project by simply dragging and dropping widgets. 

It’s really simple to set everything up and you’ll start tinkering in less than 5 mins. Blynk is not tied to some specific board or shield. Instead, it’s supporting hardware of your choice. Whether your Arduino or Raspberry Pi is linked to the Internet over Wi-Fi, Ethernet or this new ESP8266 chip, Blynk will get you online and ready for the Internet Of Your Things.” Here is the original launch video:


Blynk started off as an idea, and raised initial funding through Kickstarter – which was successful and the system has now launched. Blynk comprises of an app on your smartphone (Android or iOS) inside which you can add widgets (controls) to send commands back to your development board (Arduino etc.).

For example, you can add a switch to turn a digital output on or off. Furthermore, data from sensors connected to the development board can be send back to the smartphone. The data passes through the Blynk Cloud server, or you can download and run your own server on your own hardware and infrastructure.

How much does it cost?

Right now (September 2015) the Blynk system is free. We downloaded the app and experimented without charge. We believe that over time there will be payment required for various functions, however you can try it out now to see if Blynk suits your needs then run with it later or experiment with other platforms.

Getting Started

Well enough talk, let’s try Blynk out. Our hardware is an Android smartphone (the awesome new Oppo R7+) for control, and a Freetronics EtherTen connected to our office modem/router:

blynk etherten tronixstuff

You can also use other Arduino+Ethernet combinations, such as an Arduino Uno with an Ethernet shield. First you need to download the app for your phone – click here for the links. Then from the same page, download the Arduino library – and install it like you would any other Arduino library.

For our first example, we’ll use an LED connected to digital pin 7 (via a 560 ohm resistor) shown above. Now it’s time to set up the Blynk app. When you run the app for the first time, you need to sign in – so enter an email address and password:

blynk tronixstuff 1

Then click the “+” at the top-right of the display to create a new project, and you should see the following screen:

blynk tronixstuff 2

You can name your project, select the target hardware (Arduino Uno) – then click “E-mail” to send that auth token to yourself – you will need it in a moment. Then click “Create” to enter the main app design screen. Next, press “+” again to get the “Widget Box” menu as shown below, then press “Button”:

blynk tronixstuff 3

This will place a simple button on your screen:

blynk tronixstuff 4

Press the button to open its’ settings menu:

blynk tronixstuff 5

From this screen you can name your button, and also determine whether it will be “momentary” (i.e., only on when you press the button) – or operate as a switch (push on… push off…). Furthermore you need to select which physical Arduino pin the button will control – so press “PIN”, which brings up the scrolling menu as shown below:

blynk tronixstuff 6

We set ours to D7 then pressed “Continue”. Now the app is complete. Now head back to your computer, open the Arduino IDE, and load the “Arduino_Ethernet” sketch included with the library:

blynk example sketch tronixstuff

Then scroll down to line 30 and enter the auth key that was sent to you via email:

blynk example sketch tronixstuff auth key

Save then upload the sketch to your Arduino. Now head back to your smartphone, and click the “Play” (looks like a triangle pointing right) button. After a moment the app will connect to the Blynk server… the Arduino will also be connected to the server – and you can press the button on the screen to control the LED.

And that’s it – remote control really is that easy. We’ve run through the process in the following short video:

Now what else can we control? How about some IKEA LED strips from our last article. Easy… that consisted of three digital outputs, with PWM. The app resembles the following:

blynk tronixstuff ikea dioder

… and watch the video below to see it in action:

Monitoring data from an Arduino via Blynk

Data can also travel in the other direction – from your Arduino over the Internet to your smartphone. At the time of writing this (September 2015) you can monitor the status of analogue and digital pins, and widgets can be added in the app to do just that. They can display the value returned from each ADC, which falls between zero and 1023 – and display the values in various forms – for example:

blynk sensors tronixstuff

The bandwidth required for this is just under 2 K/s, as you can see from the top of the image above. You can see this in action through the video below:


We have only scratched the surface of what is possible with Blynk – which is an impressive, approachable and usable “Internet of Things” platform. Considering that you can get an inexpensive Android smartphone or tablet for under AU$50, the overall cost of using Blynk is excellent and well worth consideration, even just to test out the “Internet of Things” buzz yourself. So to get started head over to the Blynk site.

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


As always, have fun and keep checking into 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, blynk, Ikea, iot, tronixlabs, tronixstuff, tutorial7 Comments

Experimenting with Arduino and IKEA DIODER LED Strips


A few weeks ago I found a DIODER LED strip set from a long-ago trek to IKEA, and considered that something could be done with it.  So in this article you can see how easy it is to control the LEDs using an Arduino or compatible board with ease… opening it up to all sorts of possibilities.

This is not the most original project – however things have been pretty quiet around here, so I thought it was time to share something new with you. Furthermore the DIODER control PCB has changed, so this will be relevant to new purchases. Nevertheless, let’s get on with it.

So what is DIODER anyhow? 

As you can see in the image below, the DIODER pack includes four RGB LED units each with nine RGB LEDs per unit. A controller box allows power and colour choice, a distribution box connects between the controller box and the LED strips, and the whole thing is powered by a 12V DC plugpack:


The following is a quick video showing the DIODER in action as devised by IKEA:


Thankfully the plugpack keeps us away from mains voltages, and includes a long detachable cable which connects to the LED strip distribution box. The first thought was to investigate the controller, and you can open it with a standard screwdriver. Carefully pry away the long-side, as two clips on each side hold it together…

IKEA DIODER Arduino tronixstuff
… which reveals the PCB. Nothing too exciting here – you can see the potentiometer used for changing the lighting effects, power and range buttons and so on:

ikea dioder tronixstuff arduino

Our DIODER has the updated PCB with the Chinese market microcontroller. If you have an older DIODER with a Microchip PIC – you can reprogram it yourself.

ikea dioder arduino tronixstuff

The following three MOSFETs are used to control the current to each of the red, green and blue LED circuits. These will be the key to controlling the DIODER’s strips – but are way too small for me to solder to. The original plan was to have an Arduino’s PWM outputs tap into the MOSFET’s gates – but instead I will use external MOSFETs.

ikea dioder arduino tronixstuff

So what’s a MOSFET?

In the past you may have used a transistor to switch higher current from an Arduino, however a MOSFET is a better solution for this function. The can control large voltages and high currents without any effort. We will use N-channel MOSFETs, which have three pins – Source, Drain and Gate. When the Gate is HIGH, current will flow into the Drain and out of the Source:


A simplistic explanation is that it can be used like a button – and when wiring your own N-MOSFET a 10k resistor should be used between Gate and Drain to keep the Gate low when the Arduino output is set to LOW (just like de-bouncing a button). To learn more about MOSFETS – get yourself a copy of “The Art of Electronics“. It is worth every cent.

However being somewhat time poor (lazy?), I have instead used a Freetronics NDrive Shield for Arduino – which contains six N-MOSFETs all on one convenient shield  – with each MOSFET’s Gate pin connected to an Arduino PWM output.
freetronics ndrive shield tronixlabs

So let’s head back to the LED strips for a moment, in order to determine how the LEDs are wired in the strip. Thanks to the manufacturer – the PCB has the markings as shown below:

ikea dioder tronixstuff arduino

They’re 12V LEDs in a common-anode configuration. How much current do they draw? Depends on how many strips you have connected together…

ikea dioder arduino tronixstuff

For the curious I measured each colour at each length, with the results in the following table:


So all four strips turned on, with all colours on – the strips will draw around 165 mA of current at 12V. Those blue LEDs are certainly thirsty.

Moving on, the next step is to connect the strips to the MOSFET shield. This is easy thanks to the cable included in the DIODER pack, just chop the white connector off as shown below:

ikea dioder arduino tronixstuff

By connecting an LED strip to the other end of the cable you can then determine which wire is common, and which are the cathodes for red, green and blue.

The plugpack included with the DIODER pack can be used to power the entire project, so you will need cut the DC plug (the plug that connects into the DIODER’s distribution box) off the lead, and use a multimeter to determine which wire is negative, and which is positive.

Connect the negative wire to the GND terminal on the shield, and the positive wire to the Vin terminal.  Then…

  • the red LED wire to the D3 terminal,
  • the green LED wire to the D9 terminal,
  • and the blue LED wire to the D10 terminal.

Finally, connect the 12V LED wire (anode) into the Vin terminal. Now double-check your wiring. Then check it again.

ikea dioder tronixstuff arduino


Now to run a test sketch to show the LED strip can easily be controlled. We’ll turn each colour on and off using PWM (Pulse-Width Modulation) – a neat way to control the brightness of each colour. The following sketch will pulse each colour in turn, and there’s also a blink function you can use.

Success. And for the non-believers, watch the following video:

Better LED control

As always, there’s a better way of doing things and one example of LED control is the awesome FASTLED library by Daniel Garcia and others. Go and download it now – Apart from our simple LEDS, the FASTLED library is also great with WS2812B/Adafruit NeoPixels and others.

One excellent demonstration included with the library is the AnalogOutput sketch, which I have supplied below to work with our example hardware:

You can see this in action through the following video:

Control using a mobile phone?

Yes – click here to learn how.


So if you have some IKEA LED strips, or anything else that requires more current than an Arduino’s output pin can offer – you can use MOSFETs to take over the current control and have fun. And finally a plug for my own store – – offering a growing range and Australia’s best value for supported hobbyist electronics from adafruit, DFRobot, Freetronics, Seeed Studio and much much more.


As always, have fun and keep checking into 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, freetronics, Ikea, MOSFET, tronixlabs, tronixstuff, tutorial3 Comments

Editorial – Arduino versus Arduino

updated 27/10/2015

Over the last few months a large split in the Arduino ecosystem has been made public with some interesting results, and possibly could be the start of the end of the project as we know it. After a few people asked me directly about my thoughts on the Arduino versus Arduino matter, I’ve decided to articulate them in this editorial.

From the beginning the Arduino team has consisted of Massimo Banzi, David Cuartielles, David Mellis, Tom Igoe, and Gianluca Martino – and over the years we have always thought of this core team as the people who brought us the Arduino world.

Furthermore the main manufacturer of the Arduino-branded boards in Italy – “Smart Projects S. r. L” belongs to team member Gianluca Martino, and this organisation paid royalties to the team for the right to manufacture the boards.

Moving on, in 2008 the five formed a company to hold the trademarks and so forth that would allow for more commercial opportunities with regards to licensing and so forth.

However as Massimo wrote in a recent Make: magazine article, Gianluca had registered the Arduino name in Italy amongst other nefarious actions.

To top this off, Massimo tells us that Smart Projects have stopped paying the royalties for over twelve months. This has been most disappointing as being the supplier to Arduino resellers across the globe, resellers thought they were doing the right thing by buying the real boards. A

And to add insult to injury, Smart Projects changed their name to Arduino S. r. L., and was sold by Gianluca Martino in 2014. This company has created their own Arduino website (ending with .org instead of .cc) – and even forked their own version of the IDE and given it a version number starting with 1.7, which is greater than the current 1.6.3. No doubt this will trap a few users into thinking that Arduino S. r. L. (which we’ll shorten to ASrL) is the legitimate supplier and site for Arduino. For more information about the later developments, read this article form Hackaday.

tronixstuff and arduino versus arduino

So from what we can tell, the manufacturing member of the original Arduino team has gone off and tried to replicate the Arduino ecosystem under their own terms, allegedly misappropriating the Arduino name and trademark and denying royalties – and is currently still the only source of what have always been “genuine Arduino boards”.

Wow, what a mess.

More keen observers will realise that there isn’t anything wrong with reproducing their own Arduino-compatible boards thanks to the open-source nature of the hardware, and there must be a google of copies, compatibles and knock-offs in the market. And it’s ok to fork the IDE for modify, improve or bork it up to your own requirements as long as yout stick to the original software licence.

However the alleged royalty issue and trademark and name theft is not ok. So where does this leave the Arduino team now? From what I can learn, the rest of the original Arduino team are moving forward and will continue to innovate with new devices and projects which is admirable – and they have agreed to work with manufacturer/retailers such as adafruit to produce new boards (such as the Arduino Gemma).

At this point how does this affect you, as a potential or current Arduino enthusiast? That’s an excellent question. If you have always believed in supporting the Arduino team by purchasing genuine boards – it would seem this option is no longer available until the original team find a new manufacturing partner.

And how does this affect Arduino resellers? As an Arduino reseller ourselves ( we made our position as clear as we could at the time. Our position at Tronixlabs is that we want to continue to sell boards that benefit the Arduino team, however we’re a business that aims to meet the needs of all of our customers – and thus we offer compatibles as well.

We have contacted the Arduino team for guidance about future Arduino-branded boards and await their reply. What we do look forward to, however, is a cheaper reseller cost. The freight charge from Europe plus the board costs at the time were quite extraordinary.

Furthermore if Arduino S. r. L introduce a compelling product that people want – hey we’ll sell that as well. The following day Nate from Sparkfun made a similar statement. Whether they make their thoughts public or not, we’re confident that all resellers will take a similar stand, as you don’t want to specifically pick a side in case the other side has a great product that you want to sell. Then again, why would a manufacturer hold back their product to a retailer if said retailer offers products from the competition?

As Kent Brockman would say “… only time will tell”.

From this juncture we look forward to what the Arduino team has for us in the future with great interest… and we’re also following Arduino S. r. L as well to see what they come up with.

However don’t panic – for day to day use nothing has changed for us as enthusiasts. However – do we owe the Arduino team our support? Absolutely – so many people have benefited from their original idea and work for everyone’s benefit. If you feel so inclined, you can directly donate funds to the Arduino project via the IDE download page.

Finally, a great lesson can be learned from these recent events. If your team comes up with a great idea, product or service – before you get serious spend the time and resources required to formalise ownership of intellectual property, naming rights, copyrighted work, and so forth.

Update 27th October 2015

Not much has changed. The first “Genuino” boards are starting to appear in the EU at 20 Euro a pop, and the Mega and Micro are now available. We believe that the Arduino trademark is lost outside of the US and thus Genuino and will co-exist from the same team. This has also been reflected on the website.

The smartest buying decision is for you is to choose what you need. If what you need isn’t available from – you can always make a cash donation for their efforts via the IDE download page.

We look forward to your thoughts and notes about the situation, which can be left in our moderated comment section. And finally a plug for my own store – – offering a growing range and Australia’s best value for supported hobbyist electronics from adafruit, DFRobot, Freetronics, Seeed Studio and much much more.


As always, have fun and keep checking into 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, tronixlabs, tronixstuff6 Comments

Tutorial – Using DS1307 and DS3231 Real-time Clock Modules with Arduino

We keep getting requests on how to use DS1307 and DS3231 real-time clock modules with Arduino from various sources – so this is the first of a two part tutorial on how to use them. For this Arduino tutorial we have  two real-time clock modules to use, one based on the Maxim DS1307:


and another based on the DS3231:


There are two main differences between the ICs on the real-time clock modules, which is the accuracy of the time-keeping. The DS1307 used in the first module works very well, however the external temperature can affect the frequency of the oscillator circuit which drives the DS1307’s internal counter.

This may sound like a problem, however will usually result with the clock being off by around five or so minutes per month. The DS3231 is much more accurate, as it has an internal oscillator which isn’t affected by external factors – and thus is accurate down to a few minutes per year at the most. If you have a DS1307 module- don’t feel bad, it’s still a great value board and will serve you well.

With both of the modules, a backup battery is installed when you receive them from Tronixlabs, however these are an inexpensive variety and shouldn’t be relied on for more than twelve months. If you’re going to install the module in a more permanent project, it’s a good idea to buy a new CR2032 battery and fit it to the module.

Along with keeping track of the time and date, these modules also have a small EEPROM, an alarm function (DS3231 only) and the ability to generate a square-wave of various frequencies – all of which will be the subject of a second tutorial.

Connecting your module to an Arduino

Both modules use the I2C bus, which makes connection very easy. If you’re not sure about the I2C bus and Arduino, check out the I2C tutorials (chapters 20 and 21), or review chapter seventeen of my book “Arduino Workshop“.

Moving on – first you will need to identify which pins on your Arduino or compatible boards are used for the I2C bus – these will be knows as SDA (or data) and SCL (or clock). On Arduino Uno or compatible boards, these pins are A4 and A5 for data and clock:


If you’re using an Arduino Mega the pins are D20 and D21 for data and clock:

Arduino Mega from Tronixlabs Australia

If you’re using an Pro Mini-compatible the pins are A4 and A5 for data and clock, which are parallel to the main pins, as shown below:


DS1307 module

If you have the DS1307 module you will need to solder the wires to the board, or solder on some inline header pins so you can use jumper wires. Then connect the SCL and SDA pins to your Arduino, and the Vcc pin to the 5V pin and GND to GND.

DS3231 module

Connecting this module is easy as header pins are installed on the board at the factory. You can simply run jumper wires again from SCL and SDA to the Arduino and again from the module’s Vcc and GND pins to your board’s 5V or 3.3.V and GND. However these are duplicated on the other side for soldering your own wires.

Both of these modules have the required pull-up resistors, so you don’t need to add your own. Like all devices connected to the I2C bus, try and keep the length of the SDA and SCL wires to a minimum.

Reading and writing the time from your RTC Module

Once you have wired up your RTC module. enter and upload the following sketch. Although the notes and functions in the sketch refer only to the DS3231, the code also works with the DS1307.

There may be a lot of code, however it breaks down well into manageable parts.

It first includes the Wire library, which is used for I2C bus communication, followed by defining the bus address for the RTC as 0x68. These are followed by two functions that convert decimal numbers to BCD (binary-coded decimal) and vice versa. These are necessary as the RTC ICs work in BCD not decimal.

The function setDS3231time() is used to set the clock. Using it is very easy, simple insert the values from year down to second, and the RTC will start from that time. For example if you want to set the following date and time – Wednesday November 26, 2014 and 9:42 pm and 30 seconds – you would use:

Note that the time is set using 24-hour time, and the fourth paramter is the “day of week”. This falls between 1 and 7 which is Sunday to Saturday respectively. These parameters are byte values if you are subsituting your own variables.

Once you have run the function once it’s wise to prefix it with // and upload your code again, so it will not reset the time once the power has been cycled or micrcontroller reset.

Reading the time form your RTC Is just as simple, in fact the process can be followed neatly inside the function displayTime(). You will need to define seven byte variables to store the data from the RTC, and these are then inserted in the function readDS3231time().

For example if your variables are:

… you would refresh them with the current data from the RTC by using:

Then you can use the variables as you see fit, from sending the time and date to the serial monitor as the example sketch does – to converting the data into a suitable form for all sorts of output devices.

Just to check everything is working, enter the appropriate time and date into the demonstration sketch, upload it, comment out the setDS3231time() function and upload it again. Then open the serial monitor, and you should be provided with a running display of the current time and date, for example:


From this point you now have the software tools to set data to and retrieve it from your real-time clock module, and we hope you have an understanding of how to use these inexpensive modules.

You can learn more about the particular real-time clock ICs from the manufacturer’s website – DS1307 and DS3231.

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”.


Have fun and keep checking into 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, ds1307, DS3231, tronixlabs, tronixstuff, tutorial

Tutorial – L298N Dual Motor Controller Modules and Arduino

Learn how to use inexpensive L298N motor control modules to drive DC and stepper motors with Arduino. This is chapter fifty-nine of our huge Arduino tutorial series.

You don’t have to spend a lot of money to control motors with an Arduino or compatible board. After some hunting around we found a neat motor control module based on the L298N H-bridge IC that can allows you to control the speed and direction of two DC motors, or control one bipolar stepper motor with ease.

The L298N H-bridge module can be used with motors that have a voltage of between 5 and 35V DC. With the module used in this tutorial, there is also an onboard 5V regulator, so if your supply voltage is up to 12V you can also source 5V from the board.

So let’s get started!

L298N Dual Motor Controller Module 2A from Tronixlabs Australia

First we’ll run through the connections, then explain how to control DC motors then a stepper motor. At this point, review the connections on the L298N H-bridge module.

Consider the following image – match the numbers against the list below the image:

L298N Motor Controller for Arduino from Tronixlabs Australia

  1. DC motor 1 “+” or stepper motor A+
  2. DC motor 1 “-” or stepper motor A-
  3. 12V jumper – remove this if using a supply voltage greater than 12V DC. This enables power to the onboard 5V regulator
  4. Connect your motor supply voltage here, maximum of 35V DC. Remove 12V jumper if >12V DC
  5. GND
  6. 5V output if 12V jumper in place, ideal for powering your Arduino (etc)
  7. DC motor 1 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
  8. IN1
  9. IN2
  10. IN3
  11. IN4
  12. DC motor 2 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
  13. DC motor 2 “+” or stepper motor B+
  14. DC motor 2 “-” or stepper motor B-

Controlling DC Motors

To control one or two DC motors is quite easy with the L298N H-bridge module. First connect each motor to the A and B connections on the L298N module. If you’re using two motors for a robot (etc) ensure that the polarity of the motors is the same on both inputs. Otherwise you may need to swap them over when you set both motors to forward and one goes backwards!

Next, connect your power supply – the positive to pin 4 on the module and negative/GND to pin 5. If you supply is up to 12V you can leave in the 12V jumper (point 3 in the image above) and 5V will be available from pin 6 on the module. This can be fed to your Arduino’s 5V pin to power it from the motors’ power supply. Don’t forget to connect Arduino GND to pin 5 on the module as well to complete the circuit.

Now you will need six digital output pins on your Arduino, two of which need to be PWM (pulse-width modulation) pins. PWM pins are denoted by the tilde (“~”) next to the pin number, for example:

Arduino UNO PWM pins

Finally, connect the Arduino digital output pins to the driver module. In our example we have two DC motors, so digital pins D9, D8, D7 and D6 will be connected to pins IN1, IN2, IN3 and IN4 respectively. Then connect D10 to module pin 7 (remove the jumper first) and D5 to module pin 12 (again, remove the jumper).

The motor direction is controlled by sending a HIGH or LOW signal to the drive for each motor (or channel). For example for motor one, a HIGH to IN1 and a LOW to IN2 will cause it to turn in one direction, and  a LOW and HIGH will cause it to turn in the other direction.

However the motors will not turn until a HIGH is set to the enable pin (7 for motor one, 12 for motor two). And they can be turned off with a LOW to the same pin(s). However if you need to control the speed of the motors, the PWM signal from the digital pin connected to the enable pin can take care of it.

This is what we’ve done with the DC motor demonstration sketch. Two DC motors and an Arduino Uno are connected as described above, along with an external power supply. Then enter and upload the following sketch:

So what’s happening in that sketch? In the function demoOne() we turn the motors on and run them at a PWM value of 200. This is not a speed value, instead power is applied for 200/255 of an amount of time at once.

Then after a moment the motors operate in the reverse direction (see how we changed the HIGHs and LOWs in thedigitalWrite() functions?).

To get an idea of the range of speed possible of your hardware, we run through the entire PWM range in the function demoTwo() which turns the motors on and them runs through PWM values zero to 255 and back to zero with the two for loops.

Finally this is demonstrated in the following video – using our well-worn tank chassis with two DC motors:

Controlling a Stepper Motor

Stepper motors may appear to be complex, but nothing could be further than the truth. In this example we control a typical NEMA-17 stepper motor that has four wires:

stepper motor Tronixlabs Australia

It has 200 steps per revolution, and can operate at at 60 RPM. If you don’t already have the step and speed value for your motor, find out now and you will need it for the sketch.

The key to successful stepper motor control is identifying the wires – that is which one is which. You will need to determine the A+, A-, B+ and B- wires. With our example motor these are red, green, yellow and blue. Now let’s get the wiring done.

Connect the A+, A-, B+ and B- wires from the stepper motor to the module connections 1, 2, 13 and 14 respectively. Place the jumpers included with the L298N module over the pairs at module points 7 and 12. Then connect the power supply as required to points 4 (positive) and 5 (negative/GND).

Once again if your stepper motor’s power supply is less than 12V, fit the jumper to the module at point 3 which gives you a neat 5V power supply for your Arduino.

Next, connect L298N module pins IN1, IN2, IN3 and IN4 to Arduino digital pins D8, D9, D10 and D11 respectively. Finally, connect Arduino GND to point 5 on the module, and Arduino 5V to point 6 if sourcing 5V from the module.

Controlling the stepper motor from your sketches is very simple, thanks to the Stepper Arduino library included with the Arduino IDE as standard.

To demonstrate your motor, simply load the stepper_oneRevolution sketch that is included with the Stepper library, for example:

L298N motor controller and Arduino tutorial from Tronixlabs Australia

Finally, check the value for

in the sketch and change the 200 to the number of steps per revolution for your stepper motor, and also the speed which is preset to 60 RPM in the following line:

Now you can save and upload the sketch, which will send your stepper motor around one revolution, then back again. This is achieved with the function

Finally, a quick demonstration of our test hardware is shown in the following video:

So there you have it, an easy an inexpensive way to control motors with your Arduino or compatible board. 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”.


Have fun and keep checking into 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, L298, tronixlabs, tronixstuff, tutorial

Tutorial – PCF8574 backpacks for LCD modules and Arduino

Learn how to use inexpensive serial backpacks with character LCD modules with your Arduino. This is chapter fifty-eight of our huge Arduino tutorial series.


Using LCD modules with your Arduino is popular, however the amount of wiring requires time and patience to wire it up correctly – and also uses a lot of digital output pins. That’s why we love these serial backpack modules – they’re fitted to the back of your LCD module and allows connection to your Arduino (or other development board) with only four wires – power, GND, data and clock.

You can use this with LCD modules that have a HD44780-compatible interface with various screen sizes. For example a 16 x 2 module:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

The backpack can also be used with 20 x 4 LCDs. The key is that your LCD must have the interface pads in a single row of sixteen, so it matches the pins on the backpack – for example:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

Hardware Setup

Now let’s get started. First you need to solder the backpack to your LCD module. While your soldering iron is warming up, check that the backpack pins are straight and fit in the LCD module, for example:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

Then solder in the first pin, while keeping the backpack flush with the LCD:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

If it’s a bit crooked, you can reheat the solder and straighten it up again. Once you’re satisfied with the alignment, solder in the rest of the pins:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

Now to keep things neat, trim off the excess header pins:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

Once you’ve finished trimming the header pins, get four male to female jumper wires and connect the LCD module to your Arduino as shown in the following image and table. Then connect your Arduino to the computer via USB:

16 x 2 character LCD (white text blue background) with parallel interface from Tronixlabs Australia

Software Setup

The next step is to download and install the Arduino I2C LCD library for use with the backpack. First of all, rename the “LiquidCrystal” library folder in your Arduino libraries folder. We do this just to keep it as a backup.

If you’re not sure where your library folder can be found – it’s usually in your sketchbook folder, whose location can usually be found in the Arduino IDE preferences menu:

Next, visit… and download the latest file, currently we’re using v1.2.1. Expanding the downloaded .zip file will reveal a new “LiquidCrystal” folder – copy this into your Arduino libraries folder.

Now restart the Arduino IDE if it was already running – or open it now. To test the module we have a demonstration sketch prepared, simply copy and upload the following sketch:

After a few moments the LCD will be initialised and start to display our URL and the value for millis, then blink the backlight off and on – for example:

If the text isn’t clear, or you just see white blocks – try adjusting the contrast using the potentiometer on the back of the module.

How to control the backpack in your sketch

As opposed to using the LCD module without the backpack, there’s a few extra lines of code to include in your sketches. To review these, open the example sketch mentioned earlier.

You will need the libraries as shown in lines 3, 4 and 5 – and initialise the module as shown in line 7. Note that the default I2C bus address is 0x27 – and the first parameter in the LiquidCrystal_I2C function.

Finally the three lines used in void setup() are also required to initialise the LCD. If you’re using a 20×4 LCD module, change the parameters in the lcd.begin() function.

From this point you can use all the standard LiquidCrystal functions such as lcd.setCursor() to move the cursor and lcd.write() to display text or variables as normal. The backlight can also be turned on and off with lcd.setBacklight(HIGH) or lcd.setBacklight(LOW).

You can permanently turn off the backlight by removing the physical jumper on the back of the module.

Changing the I2C bus address

If you want to use more than one module, or have another device on the I2C bus with address 0x27 then you’ll need to change the address used on the module. There are eight options to choose from, and these are selected by soldering over one or more of the following spots:

There are eight possible combinations, and these are described in Table 4 of the PCF8574 data sheet which can be downloaded from the NXP website. If you’re unsure about the bus address used by the module, simply connect it to your Arduino as described earlier and run the I2C scanner sketch from the Arduino playground.

We hope you enjoyed this tutorial and you can make use of it. Finally, if you enjoyed this tutorial, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a fourth printing!) “Arduino Workshop”.


Have fun and keep checking into 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, LCD, PCF8574, tronixlabs, tronixstuff, tutorial

Arduino Workshop – A Hands-On Introduction with 65 Projects

Over the last few years you may have noticed a few of my 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 first book – “Arduino Workshop“:

Arduino Workshop book

Now into the fourth print run, “Arduino Workshop” is one of the few books on the market that can take the reader from zero knowledge to understanding the Arduino development platform, and working with a huge array of add-ons and technologies. You don’t need to buy any other preliminary book – this starts from the absolute beginning. And a huge “thank you” to all those who have purchased and supported the book so far – and it’s now available in Traditional Chinese, Korean, German and Polish.

Arduino Workshop” offers a professionally edited and curated path for the beginner to learn with and have fun. It’s a hands-on introduction to Arduino with 65 projects – from simple LED use right through to RFID, Internet connection, wireless data, working with cellular communications, and much more. Plus the reader also learns about electronics, good coding and other interesting topics.


Each project is explained in detail, explaining how the hardware and Arduino code works together. Plus we teach you how to read and understand circuit schematics and use this clear method of describing circuits which prepares the read for further electronics learning.

Arduino Workshop piezo

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 at No Starch Press, our technical editor Marc Alexander 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. If you’re still not sure, 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 DRM-free eBook (PDF, Mobi, and ePub) formats. And the eBooks are also included with the printed orders from No Starch Press so you can get started immediately. 

Autographed copies are available from Tronixlabs

Furthermore for readers outside of the United States wishing to save on postage, Arduino Workshop is available from many stores in various countries, for example:

And you can also find Arduino Workshop for sale from all the popular booksellers around the globe such as Amazon, Barnes and Noble, and so on.


Have fun and keep checking into 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, Arduino Workshop, book, lesson, tutorial

Add long-distance connectivity to your Arduino with the CATkit System


Have you ever wanted to connect your Arduino to sensors or other devices but over a long distance? And we don’t mean a few metres – instead, distances of up to 100 metres? Doing so is possible with the CATkit system from SMART greenhouse.

This system is a combination of small boards that are connected between your Arduino and external devices using CAT5 networking cable, giving a very simple method of connecting devices over distances you previously thought may not have been possible – or have used costly wireless modules in the past.

The maximum distances possible depend on the signal type, for example:

  • analogue signals up to 100 metres (with a 0.125 V drop)
  • 1-wire signals (ideal for DS18B20 temperature sensors) up to 75 metres
  • SPI bus up to 50 metres
  • I2C bus up to 35 metres
  • Serial data at 9600 bps varies between 50 and 100 metres

In principle you could also use this with other development boards that utilise the Arduino Uno shield form-factor and work with 5V – so not for the Arduino Due, etc. For more information check out the .pdf documentation at the bottom of this page.

How it works

For each system you need one CATkit Arduino shield:


… and one or more Kitten boards. These are both inline – in that they can “tap in” to a run:


or have one RJ45 socket for installation at the end of a cable run:


Note that the inline Kitten has male pins for the breakout, and the end unit has females. These units are available in kit form or assembled. You then use the network cables between the shield and each Kitten, for example:


Each Kitten can distribute six signals, and up to three can be connected to one CATkit shield. These three distribute analogue pins 0~5, digital pins 0~5 and 6~11 respectively. You can also introduce external power to the CATkit shield and the onboard regulator will offer 5V at up to 950 mA for the power bus which can be accessed from the inline or end Kitten boards. This saves having to provide separate 5V power to devices away from the Arduino, and very convenient for sensors or remote I2C-interface displays.  

Using the CATkit system

If you have the units in kit form, assembly is very simple. For example – the main CATkit shield:


The shield is in the latest Arduino R3 format, and all the required parts are included. The PCB is neatly solder-masked and silk-screened so soldering is easy. The power regulator is in D-PAK form, however with a little help it’s easy to solder it in:


Otherwise the shield assembly is straight forward, and in around ten minutes you have the finished product (somehow we lost the DC socket, however one is included):


The cut-out in the PCB gives a neat clearance for the USB socket.  The inline unit was also easily assembled, and again the kit includes all the necessary parts:


… and after a few minutes of soldering the board is ready:


A benefit of using the kit version is that you can directly solder any wires from sensors straight to the PCB for more permanent installations. 

Using the CATkit system

Any Arduino user with a basic understanding of I/O will be ready for the CATkit system. You can think of it as a seamless extension to the required I/O pins, taking into account the maximum distances possible as noted on the CATkit website or earlier in this review.

For a quick test we connected an I2C-interface LCD using an inline Kitten module via 5M of network cable, as shown in this video.


With a little planning and the CATkit system you can create neat plug-and-play sensor or actuator networks with reusable lengths of common networking cable. To do so is simple – and it works, so for more information and distributors please visit the product website.

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”.


Have fun and keep checking into 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 – CATkit system parts are a promotional consideration from SMART green house]

Posted in arduino, catkit, kit review, tronixstuff

Review – Intel Galileo Arduino-compatible Development Board


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.


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 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.


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”.


Have fun and keep checking into 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 and not a promotional consideration]

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

Tutorial – Arduino and TFT Color Touch Screen

Learn how to use an inexpensive TFT colour  touch LCD shield with your Arduino. This is chapter twenty-nine of our huge Arduino tutorial series.

Updated 07/02/2014

There are many colour LCDs on the market that can be used with an Arduino, and in this tutorial we’ll explain how to use a model that is easy to use, has a touch screen, doesn’t waste all your digital output pins – and won’t break the bank. It’s the 2.8″ TFT colour touch screen shield from Tronixlabs:

Arduino TFT colour touch shield front

And upside down:

Arduino TFT colour touch shield back

As you can imagine, it completely covers an Arduino Uno or compatible board, and offers a neat way to create a large display or user-interface.  The display has a resolution of 320 x 240 pixels, supports up to 65536 colours and draws around 250mA of current from the Arduino’s internal 5V supply. 

And unlike other colour LCDs, this one doesn’t eat up all your digital output pins – it uses the SPI bus for the display (D10~D13), and four analogue pins (A0~A3) if you use the touch sensor. However if you also use the onboard microSD socket more pins will be required. 

With some imagination, existing Arduino knowledge and the explanation within you’ll be creating all sorts of displays and interfaces in a short period of time. Don’t be afraid to experiment!

Getting started

Setting up the hardware is easy – just plug the shield on your Arduino. Next, download the library bundle from here. Inside the .zip file is two folders – both which need to be copied into your …\Arduino-1.0.x\libraries folder. Then you will need to rename the folder “TFT_Touch” to “TFT”. You will notice that the Arduino IDE already contains a library folder called TFT, so rename or move it.

Now let’s test the shield so you know it works, and also to have some quick fun. Upload the paint example included in the TFT library – then with a stylus or non-destructive pointer, you can select colour and draw on the LCD – as shown in this video. At this point we’d like to note that you should be careful with the screen – it doesn’t have a protective layer.

Afraid the quality of our camera doesn’t do the screen any justice, however the still image looks better:

Arduino TFT colour touch shield paint demonstration

Using the LCD 

Moving on, let’s start with using the display. In your sketches the following libraries need to be included using the following lines before void setup():

… and then the TFT library is initialised in void setup()

Now you can use the various functions to display text and graphics. However you first need to understand how to define colours.

Defining colours

Functions with a colour parameter can accept one of the ten ten predefined colours – RED, GREEN, BLUE, BLACK, YELLOW, WHITE, CYAN, BRIGHT_RED, GRAY1 and GRAY2, or you can create your own colour value. Colours are defined with 16-but numbers in hexadecimal form, with 5 bits for red, 6 for green and 5 for blue – all packed together. For example – in binary:

These are called RGB565-formatted numbers – and we use these in hexadecimal format with our display. So black will be all zeros, then converted to hexadecimal; white all ones, etc. The process of converting normal RGB values to RGB565 would give an aspirin a headache, but instead thanks to Henning Karlsen you can use his conversion tool to do the work for you. Consider giving Henning a donation for his efforts.

Displaying text

There are functions to display characters, strings of text, integers and float variables:

In each of the functions, the first parameter is the variable or data to display; x and y are the coordinates of the top-left of the first character being displayed; and colour is either the predefined colour as explained previously, or the hexadecimal value for the colour you would like the text to be displayed in – e.g. 0xFFE0 is yellow.

The drawFloat() function is limited to two decimal places, however you can increase this if necessary. To do so, close the Arduino IDE if running, open the file TFTv2.cpp located in the TFT library folder – and search for the line:

… then change the value to the number of decimal places you require. We have set ours to four with success, and the library will round out any more decimal places. To see these text display functions in action,  upload the following sketch:

… which should result in the following:

Arduino TFT colour touch shield text

To clear the screen

To set the screen back to all black, use:

Graphics functions

There are functions to draw individual pixels, circles, filled circles, lines, rectangles and filled rectangles. With these and a little planning you can create all sorts of images and diagrams. The functions are:

The following sketch demonstrates the functions listed above:

… with the results shown in this video.

Using the touch screen

The touch screen operates in a similar manner to the other version documented earlier, in that it is a resistive touch screen and we very quickly apply voltage to one axis then measure the value with an analogue pin, then repeat the process for the other axis.

You can use the method in that chapter, however with our model you can use a touch screen library, and this is included with the library .zip file you downloaded at the start of this tutorial.

The library does simplify things somewhat, so without further ado upload the touchScreen example sketch included with the library. Open the serial monitor then start touching the screen. The coordinates of the area over a pixel being touch will be returned, along with the pressure – as shown in this video.

Take note of the pressure values, as these need to be considered when creating projects. If you don’t take pressure into account, there could be false positive touches detected which could cause mayhem in your project.

Now that you have a very simple method to determine the results of which part of the screen is being touched – you can create sketches to take action depending on the touch area. Recall from the example touch sketch that the x and y coordinates were mapped into the variables p.x and p.y, with the pressure mapped to p.z. You should experiment with your screen to determine which pressure values work for you.

In the following example, we don’t trigger a touch unless the pressure value p.z is greater than 300. Let’s create a simple touch-switch, with one half of the screen for ON and the other half for OFF. Here is the sketch:

What’s happening here? We divided the screen into two halves (well not physically…) and consider any touch with a y-value of less than 160 to be the off area, and the rest of the screen to be the on area. This is tested in the two if functions – which also use an and (“&&”) to check the pressure. If the pressure is over 300 (remember, this could be different for you) – the touch is real and the switch is turned on or off.

… and a quick demonstration video of this in action.

Displaying images from a memory card

We feel this warrants a separate tutorial, however if you can’t wait – check out the demo sketch which includes some example image files to use.


By now I hope you have the answer to “how do you use a touch screen LCD with Arduino?” and had some fun learning with us. You can get your LCD from Tronixlabs. 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”.


Have fun and keep checking into 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, LCD, TFT, touch screen, tronixlabs, tronixstuff, tutorial

Tutorial – Arduino and Color LCD

Learn how to use an inexpensive colour LCD shield with your Arduino. This is chapter twenty-eight of our huge Arduino tutorial series.

Updated 03/02/2014

There are many colour LCDs on the market that can be used with an Arduino, and for this tutorial we’re using a relatively simple model available that is available from suppliers such as Tronixlabs, based on a small LCD originally used in Nokia 6100 mobile phones:

Arduino Color LCD shield

These are a convenient and inexpensive way of displaying data, or for monitoring variables when debugging a sketch. Before getting started, a small amount of work is required.

From the two examples we have seen, neither of them arrive fitted with stacking headers (or in Sparkfun’s case – not included) or pins, so before doing anything you’ll need to fit your choice of connector. Although the LCD shield arrived with stacking headers, we used in-line pins as another shield would never be placed on top:

Arduino Color LCD shield fit headers

Which can easily be soldered to the shield in a few minutes:

Arduino Color LCD shield fitted

 While we’re on the subject of pins – this shield uses D3~D5 for the three buttons, and D8, 9, 11 and 13 for the LCD interface. The shield takes 5V and doesn’t require any external power for the backlight. The LCD module has a resolution of 128 x 128 pixels, with nine defined colours (red, green, blue, cyan, magenta, yellow, brown, orange, pink) as well as black and white.

So let’s get started. From a software perspective, the first thing to do is download and install the library for the LCD shield. Visit the library page here. Then download the .zip file, extract and copy the resulting folder into your ..\arduino-1.0.x\libraries folder. Be sure to rename the folder to “ColorLCDShield“. Then restart the Arduino IDE if it was already open.

At this point let’s check the shield is working before moving forward. Once fitted to your Arduino, upload the ChronoLCD_Color sketch that’s included with the library, from the IDE Examples menu:

Arduino Color LCD shield example sketch

This will result with a neat analogue clock you can adjust with the buttons on the shield, as shown in this video.

It’s difficult to photograph the LCD – (some of them have very bright backlights), so the image may not be a true reflection of reality. Nevertheless this shield is easy to use and we will prove this in the following examples. So how do you control the color LCD shield in your sketches?

At the start of every sketch, you will need the following lines:

as well as the following in void setup():

With regards to lcd.init(), try it first without a parameter. If the screen doesn’t work, try EPSON instead. There are two versions of the LCD shield floating about each with a different controller chip. The contrast parameter is subjective, however 63 looks good – but test for yourself.

Now let’s move on to examine each function with a small example, then use the LCD shield in more complex applications.

The LCD can display 8 rows of 16 characters of text. The function to display text is:

where x and y are the coordinates of the top left pixel of the first character in the string. Another necessary function is:

Which clears the screen and sets the background colour to the parameter colour.  Please note – when referring to the X- and Y-axis in this article, they are relative to the LCD in the position shown below. Now for an example – to recreate the following display:

Arduino Color LCD shield text demonstration

… use the following sketch:

In example 28.1 we used the function lcd.clear(), which unsurprisingly cleared the screen and set the background a certain colour.

Let’s have a look at the various background colours in the following example. The lcd.clear()  function is helpful as it can set the entire screen area to a particular colour. As mentioned earlier, there are the predefined colours red, green, blue, cyan, magenta, yellow, brown, orange, pink, as well as black and white. Here they are in the following example:

And now to see it in action. In this demonstration video the colours are more livid in real life, unfortunately the camera does not capture them so well.


Now that we have had some experience with the LCD library’s functions, we can move on to drawing some graphical objects. Recall that the screen has a resolution of 128 by 128 pixels. We have four functions to make use of this LCD real estate, so let’s see how they work. The first is:

This function places a pixel (one LCD dot) at location x, y with the colour of colour.

Note – in this (and all the functions that have a colour parameter) you can substitute the colour (e.g. BLACK) for a 12-bit RGB value representing the colour required. Next is:

Which draws a line of colour COLOUR, from position x0, y0 to x1, y1. Our next function is:

This function draws an oblong or square of colour COLOUR with the top-left point at x0, y0 and the bottom right at x1, y1. Fill is set to 0 for an outline, and 1 for a filled oblong. It would be convenient for drawing bar graphs for data representation. And finally, we can also create circles, using:

X and Y is the location for the centre of the circle, radius and COLOUR are self-explanatory. We will now use these graphical functions in the following demonstration sketch:

The results of this sketch are shown in this video. For photographic reasons, I will stick with white on black for the colours.

So now you have an explanation of the functions to drive the screen – and only your imagination is holding you back.


Hopefully this tutorial is of use to you. and you’re no longer wondering “how to use a color LCD with Arduino”. They’re available from our tronixlabs store. 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”.


Have fun and keep checking into 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, LCD, LCD-09363, Linksprite, SHD_LCD_NOKIA, sparkfun, tronixstuff, tutorial0 Comments

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


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 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.


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”.


Have fun and keep checking into 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

Easily test and experiment with GSM modules using AT Command Tester


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 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.


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”.


Have fun and keep checking into 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, AT command, GSM, software review, tronixstuff

Online data analysis with Arduino and plotly


It’s 2014 and the Internet-of-Things is flying along at a rapid rate with all sorts of services and devices that share data and allow control via the Internet. In the spirit of this we look a new service called plotly.

This is a “collaborative data analysis and graphing tool” which allows you to upload your own data to be analysed in many ways, and then graph the results using all sorts of plot types.

With plotly you can run your own mathematical functions over your data, run intense statistical analysis and use or edit one of the many APIs (PythonMATLABRJuliaRESTArduino, or Perl) to increase the level of customisation. Plotly works in conjunction with Google Drive to store your data, however this can be exported and imported without any issues. Futhermore plotly works best in Google Chrome.

For our review we’ll look at using plotly to quickly display and analyse data received from an Internet-connected Arduino – our EtherTen, or you can use almost any Arduino and Ethernet shield. The system isn’t completely documented however by revieiwng our example sketch and some experimenting with the interface plotly is very much usable, even in its current beta format.

Getting started with plotly

You will need to setup a plotly account, and this is simply accomplished from their main site. Some of you may be wondering what plotly costs – at the time of writing plotly is free for unlimited public use (that is – anyone can see your data with the right URL), but requires a subscription for extended private use. You can find the costs at the plans page.

Once you have a plotly account, visit your plotly home page, whose URL is – then click “edit profile”. Another window will appear which amongst other things contains your plotly API key – make a note of this as you will need it and your username for the Arduino sketch.

Next, you’ll need some Arduino or compatible hardware to capture the data to log and analyse. An Arduino with an Ethernet or WiFi connection, and appropriate sensors for your application. We have our EtherTen that takes readings from a temperature/humidity sensor and a light level sensor:

Freetronics EtherTen Arduino Plotly

Now you need a new Arduino library, which is available from the plotly API page. Lots of APIs there… Anyhow, click “Arduino” and you will arrive at the github page. Download the entire .zip file, and extract the plotly_ethernet folder into Arduino libraries folder which in most installations can be found at ..\Arduino-1.0.x\libraries. 

plotly arduino library folder

Finally we’ll use a demonstration sketch provided by plotly and modify this to our needs, which can be downloaded from github. We’ll go through this sketch and show you what to update – so have a quick look and then at out example sketch at the end of this section.

First, insert any code required to get data from your sensors and store the data in a variable – do this so the values can be used in void loop. Next, update the MAC address and the IP address of your Ethernet-enabled Arduino with the following lines:

and change the MAC and IP if necessary. If Arduino and Ethernet is new to you, check out the tutorial. Now look for the following two lines and enter your plotly username and API key:

Next – it’s a good idea to set your time zone, so the time in plots makes sense. Add the following two lines in void setup():

You can find a list of time zones available for use with plotly here. Now you need to determine how many traces and points to use. A trace is one source of data, for example temperature. For now you will have one point, so set these parameters using the following lines:

For example, we will plot temperature, humidity and light level – so this requires three traces. The next step is to set the filename for the plot, using the following line:

This will be sent to plotly and your data will be saved under that name. At the point in your sketch where you want to send some data back to plotly, use:

… then the following for each trace:

where data is the variable to send back to plotly. We use millis() as our example is logging data against time.

To put all that together, consider our example sketch with the hardware mentioned earlier:

After wiring up the hardware and uploading the sketch, the data will be sent until the power is removed from the Arduino.

Monitoring sensor data

Now that your hardware is sending the data off to plotly, you can check it out in real time. Log into plotly and visit the data home page – – for example:

plotly home data page

Your data file will be listed – so just click on the file name to be presented with a very basic graph. Over time you will see it develop as the data is received, however you may want to alter the display, headings, labels and so on. Generally you can click on trace labels, titles and so on to change them, the interface is pretty intuitive after a few moments. A quick screencast of this is shown in this video.

To view and analyse the raw data – and create all sorts of custom plots, graphs and other analysis – click the “view data in grid” icon which is the second from the left along the bar:

view data grid button

At which point your data will be displayed in a new tab:

plotly arduino data grid

From this point you can experiment to your heart’s content – just don’t forget to save your work. In a short amount of time your data can be presented visually and analysed with ease:

plotly arduino data graph


Although plotly is still in beta form, it works well and the developers are responsive to any questions – so there isn’t much more to say but give it a try yourself, doing so won’t cost you anything and you can see how useful plotly is for yourself. 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”.


Have fun and keep checking into 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 API, arduino, ethernet, plotly, tronixstuff, tutorial0 Comments

Tutorial – Arduino Mega and SM5100B GSM Cellular

Shield is now out of date so tutorial has been removed. Contact your hardware supplier for support.

Posted in arduino, GSM, shield, tronixlabs, tronixstuff, tutorial

Tutorial – Arduino and MediaTek 3329 GPS

Learn how to use MediaTek 3329-based GPS shields with Arduino in Chapter 19 of our Arduino Tutorials. The first chapter is here, the complete series is detailed here. If you have an EM406A GPS module, please visit the separate tutorial. Updated 15/01/2014


In this instalment we will introduce and examine the use of the Global Positioning System receivers with Arduino systems. What is the GPS? In very simple terms, a fleet of satellites orbit the earth, transmitting signals from space. Your GPS receiver uses signals from these satellites to triangulate position, altitude, compass headings, etc.; and also receives a time and date signal from these satellites.

The most popular GPS belongs to the USA, and was originally for military use – however it is now available for users in the free world.

Interestingly, the US can switch off or reduce accuracy of their GPS in various regions if necessary, however many people tell me this is not an issue unless you’re in a combat zone against the US forces. For more information, have a look at Wikipedia or the USAF Space Command GPS Ops Centre site. As expected,  other countries have their own GPS as well – such as Russia, China, and the EU is working on one as well.

So – how can us mere mortals take advantage of a multi-billion dollar space navigation system just with our simple Arduino? Easy – with an inexpensive GPS receiver and shield. In this tutorial we’ll use a GPS shield based on the MediaTek3329 GPS receiver from Tronixlabs.

Unlike the EM406A used in the other tutorial, the whole lot is all on one shield – and after some experimenting has better reception. Plus there’s an onboard SD card socket which we’ll use for a GPS logging device. The only catch is that you need to solder the stacking headers yourself. (update – if purchased from Tronixlabs these will be fully assembled):

Linksprite Arduino GPS SD card shield

Apart from the GPS shield we’ll also be using a typical Arduino-compatible LCD shield and of course an Arduino Uno or compatible. Finally before getting started, you need to set the two jumpers on the GPS shield as shown in the following image:

Linksprite GPS Arduino shield jumpers

By doing this the serial data lines from the GPS receiver can be connected to Arduino D2 and D3 – which we will use with SoftwareSerial. The benefit of doing it this way is that you can then upload sketches without any hardware changes and also use the serial monitor and GPS at the same time. So let’s get started.

Testing your GPS shield

Simply connect your GPS shield as described above to your Arduino Uno or compatible, and upload the following sketch:

Note the use of SoftwareSerial in the sketch. As mentioned earlier, the GPS data is transferred to the Arduino via D2/D2 – which we set up as a software serial port.

If possible try to get your hardware close to a window, then open the serial monitor window. The first time you power up your receiver, it may take a  minute or so to lock onto the available satellites, this period of time is the cold start time.

The subsequent times you power it up, the searching time is reduced somewhat as our receiver stores some energy in a supercap (very high-value capacitor) to remember the satellite data, which it will use the next time to reduce the search time (as it already has a “fair idea” where the satellites are).

Moving on, after a few moments you should be presented with a scrolling wall of text, for example:

Arduino GPS raw NMEA data

What on Earth does all that mean? For one thing the hardware is working correctly. Excellent! Now how do we decode these space-signals… They are called NMEA codes. Let’s break down one and see what it means. For example, the line:

  • $GPRMC tells us the following data is essential point-velocity-time data;
  • 100748.000 is the universal time constant (Greenwich Mean Time) – 10:07:48 (hours, minutes, seconds). So you now have a clock as well.
  • A is status – A for active and data is valid, V for void and data is not valid.
  • 3754.9976  is degrees latitude position data = 37 degrees, 54.9976′
  • S for south (south is negative, north is positive)
  • 14507.0283 is degrees longitude position data = 145 degrees, 07.0283′
  • E for east (east is positive, west is negative)
  • 0.00 is my speed in knots over ground. This shows the inaccuracy  that can be caused by not having a clear view of the sky
  • 263.36 – course over ground (0 is north, 180 is south, 270 is west, 90 is east)
  • 140114 is the date – 14th January 2014
  • the next is magnetic variation for which we don’t have a value
  • checksum number

Thankfully the data is separated by commas. This will be useful later when you log the data to a text file using the SD card, as you will then be able to use the data in a spreadsheet very easily. For more explanation about the data, here is the NMEA Reference Manual that explains them all.

Extracting the GPS data

You can’t decode all that NMEA on the fly, so thankfully there is an Arduino library to do this for us – TinyGPS. So head over to the library website, download and install the library before continuing.

Now with the same hardware from the previous example, upload the following sketch:

How this works is quite simple. In void loop() the sketch waits for data to come from the GPS receiver, and then checks if it’s valid GPS data. Then it passes over to the function getgps() which uses the function:

to extract the location data and place it in two variables. Next, another function:

will extract the date and time data, and place them in the pre-determined variables. Finally the use of


can be assigned to variables as they store the altitude and speed respectively. These functions will be commonly used across all the examples, so you can see how they can be used.

To test the sketch, position the hardware and open the serial monitor. After a moment you should be presented with the GPS data in a much more useful form, for example:

Arduino GPS data

At this point you should be able to form ideas of how to harness that data and display or work with it in a more useful way. Useful hint – you can enter coordinates directly into Google Maps to see where it is, for example:

GPS data in Google Maps

 A portable GPS display

Now that you can extract the GPS data, it’s a simple matter of sending it to an LCD shield for display. Just add the LCD shield to your hardware and upload the next sketch. Be sure to change the values in the LiquidCrysal LCD… line if your shield uses different digital pins.

Again, position the hardware and your current position should be shown on the LCD, for example:

Arduino GPS LCD

A GPS Clock

Armed with the same hardware you can also create a GPS clock. With this you can finally have a reference clock and end all arguments about the correct time without calling the speaking clock. Just use the same hardware from the previous example and upload the following sketch:

Now position the hardware again, and after a moment the time will appear – as shown in this video.

Unless you live in the UK or really need to know what GMT/UTC is, a little extra work is required to display your local time. First you will need to know in which time zone you are located – find it in this map.

If your time zone is positive (e.g. GMT +10) – you need to add 10 to your hour value, and if it’s over 23 you then subtract 24 to get the correct hours.

If your time zone is negative (e.g. GMT – 5) – you need to subtract 5 from your hour value, and if it’s under zero  you then add 24 to get the correct hours.

GPS Speedometer

Just as with the clock, it’s easy to display the speed readings with the LCD. Using the same hardware as above, enter and upload the following sketch:

Now position the hardware again, and after a moment your speed should appear. You might get some odd readings if indoors, as the receiver needs data from several satellites to accurately determine your speed. The sketch is written for km/h, however you can replace the display lines with the section that is commented out to display miles per hour.

So at this point find a car and driver, an external power supply and go for a drive. You may find the GPS speed is quite different to the vehicle’s speedometer.

Build a GPS logging device

And for our final example, let’s make a device that captures the position, speed and time data to SD card for later analysis. The required hardware is just the GPS shield and Arduino Uno or compatible board – plus an SD memory card that is formatted to FAT16. SDXC cards may or may not work, they’re quite finicky – so try and get an older standard card.

Now enter and upload the following sketch:

This will append the data to a text file whose name is determine in line 34 of the sketch. If you are using a different GPS shield or a separate SD card shield you may need to change the digital pin value for the chip select line, which is found in lines 14 and 18. The data in our example is logged every ten seconds, however you can change the frequency using the delay() function in line 73.

When you’re ready to start capturing data, simply insert the card and power up the hardware. It will carry on until you turn it off, at which point the data file can be examined on a PC. As an example capture, I took the hardware for a drive, and ended with a file containing much data – for example:

Arduino GPS logging example data

For a more graphical result, you can import the data using a third-party service into Google Maps to get a better idea of the journey. But first, the text file requires a little work. Open it as a text file using a typical spreadsheet, which will then ask how to organise the columns. Delimit them with a space, for example:

delimit Arduino GPS data

Which will give you a spreadsheet of the data. Now delete all the columns except for the latitude and longitude data, and add a header row as such:

GPS data in spreadsheet

Now save that file as an .xls spreadsheet. Next, visit the GPS Visuliser website, and upload the file using the box in the centre of the page. Select “Google Maps” as the output format, and your trip will be presented – for example:

GPS trip map

There are many options on the visualiser site, so if you end up using it a lot – consider giving them a donation.


Now you have some easy example sketches that demonstrate how to extract and work with data from your GPS shield. For the curious, the static GPS locations displayed in this tutorial are not our current location. 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”.


Have fun and keep checking into 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, GPS, Mediatek 3329, shield, SKM58, tronixlabs, tronixstuff, tutorial0 Comments

Project – Arduino “Book Monster”


Recently we saw a neat project by the people from Evil Mad Scientist – their “Peek-O-Book“, a neat take on a book with a shy monster inside, based on hardware from their Snap-O-Lantern kit. Not wanting to fork out for the postage to Australia we decided to make our own version, of which you can follow along.

This is a fun project that doesn’t require too much effort and has a lot of scope for customisation. There’s no right or wrong when making your own (or this one!) so just have fun with it.


First, you’ll need a book of some sort, something large enough to hide the electronics yet not too large to look “suspicious” – then cut the guts out to make enough space for the electronics. Then again it’s subjective, so get whatever works for you. Coincidentally we found some “dummy books” (not books for dummies) that were perfect for the job:

dummy book

After spraying the inside with matt black paint, the inside is better suited for the “eyes in the dark” effect required for the project:

dummy book internal

The “book” had a magnet and matching metal disk on the flap to aid with keep the cover shut, however this was removed as it will not allow for smooth opening with the servo.

The electronics are quite simple if you have some Arduino or other development board experience. Not sure about Arduino? You can use any microcontroller that can control a servo and some LEDs. We’re using a Freetronics LeoStick as it’s really small yet offers a full Arduino Leonardo-compatible experience, and a matching Protostick to run the wires and power from:

Freetronics Leostick and Protostick

By fitting all the external wiring to the Protostick you can still use the main LeoStick for other projects if required. The power is from 4 x AA cells, with the voltage reduced with a 1n4004 diode:

battery power and diode

And for the “eyes” of our monster – you can always add more if it isn’t too crowded in the book:

Arduino LEDs

We’ll need a resistor as well for the LEDs. As LEDs are current driven you can connect two in series with a suitable dropping resistor which allows you to control both if required with one digital output pin. You can use the calculator here to help determine the right value for the resistor.

Finally a servo is required to push the lid of the book up and down. We used an inexpensive micro servo that’s available from Tronixlabs:

Arduino servo

The chopsticks are cut down and used as an extension to the servo horn to give it more length:

Arduino servo mounted

Don’t forget to paint the arm black so it doesn’t stand out when in use. We had a lazy attack and mounted the servo on some LEGO bricks held in with super glue, but it works. Finally, here is the circuit schematic for our final example – we also added a power switch after the battery pack:

book monster schematic small

To recap  – this is a list of parts used:

After some delicate soldering the whole lot fits neatly in the box:

Arduino book monster final

Arduino Sketch

The behaviour of your “book monster” comes down to your imagination. Experiment with the servo angles and speed to simulate the lid opening as if the monster is creeping up, or quickly for a “pop-up” surprise. And again with the LED eyes you can blink them and alter the brightness with PWM. Here’s a quick sketch to give you an idea:

You can watch our example unit in this video.

Frankly the entire project is subjective, so just do what you want.


Well that was fun, and I am sure this will entertain many people. A relative is a librarian so this will adorn a shelf and hopefully give the children a laugh. Once again, thanks to the people from Evil Mad Science for the inspiration for this project – so go and buy something from their interesting range of kits and so on.

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”.


Have fun and keep checking into 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, evil mad science, freetronics, leostick, projects, tronixlabs, tronixstuff, tutorial0 Comments

Arduino Tutorials – Chapter 42 – Numeric Keypads

Learn how to use various numeric keypads with your Arduino.

This is chapter forty-two of our huge Arduino tutorial seriesUpdated 16/12/2013

Numeric keypads can provide a simple end-user alternative for various interfaces for your projects. Or if you need a lot of buttons, they can save you a lot of time with regards to construction. We’ll run through connecting them, using the Arduino library and then finish with a useful example sketch.

Getting Started

Numeric keypads are available from many retailers, and no matter where you get them from, make sure you can get the data sheet, as this will make life easier when wiring them up. Here are the two examples for our tutorial, from Futurlec (slow and cheap):

Arduino numeric keypads

 Again, the data sheet is important as it will tell you which pins or connectors on the keypad are for the rows and columns, for example the black keypad shown above. If you don’t have the data sheet – you will need to manually determine which contacts are for the rows and columns.

This can be done using the continuity function of a multimeter (the buzzer). Start by placing one probe on pin 1, the other probe on pin 2, and press the keys one by one. Make a note of when a button completes the circuit, then move onto the next pin. Soon you will know which is which. For example, on the example keypad pins 1 and 5 are for button “1″, 2 and 5 for “4″, etc…

Furthermore some keypads will have the pins soldered to the end, some will not. With our two example keypads, the smaller unit had the pins – and we soldered pins to the large white unit: