Tiny little Arduinos…

So, in my quest to create fabulous wearable futures for jewellery lovers, I have come to a point where I have to bite the bullet and get deeply involved in the microelectronics side of my research. The arrival of the Ultimaker has pushed my material experimentation to a whole new level, and the moment has finally come to start creating first assemblies of both materials and electronic components for my symbiotic jewellery objects.

Since I started my research, a lot has happened in the world of wearable computing – particularly in terms of miniaturisation, but also to some extent functionality. There seems to be more of an appetite now for developers to release ever-smaller processors and exciting sensors to the hacker community, and more and more people are starting to use them. For someone like me who is just starting out with electronics (and even after extensive reading and research around the subject for the last three years I would still consider myself a beginner) this is a blessing, as a larger user base means more community support in the shape of blogs, forums and user guides. The Adafruit website has a humungous database of learning projects, starting from scratch with the very basics and ranging all the way to the sublime. Another great resource for getting started is the Sparkfun website, which has a great learning section as well as a user forum. If you live in the States either one of these are very handy for you – just choose a project and order the components to go with it directly from the supplier. In the UK, you have to go through third party retailers, but between them they usually have the full range of components available (including some more from other brands).

In my latest efforts to intergrate electronics into jewellery, I was delighted to find that since I last looked in 2013, not one but five new Arduino-based microcontroller boards had been developed in an appropriate size range for wearables. Brilliant News!…Now which one to choose??? For a previous project, I had dipped my toes into using the Arduino Pro Mini 328 5V and 3.3V boards, which are a great little option if you need a lot of output pins and a reset button. I still have two of those in the workshop, and I am sure they will come to be used in the near future for one of my larger, more elaborate pieces. But they are rectangular in shape, and a bit awkward to use within the more rounded, organic shapes I have been making of late. Also they are quite possibly processing overkill for what I am trying to (and capable of) do in terms of programming. They have a similar functionality to the much larger Arduino Uno, which is definitely a lot more than I need at this point, although I like using one for running prototype programs and test the wired connections.

An immediately appealing option for using in my projects were the Adafruit Flora and Gemma, with the latter being smaller, with fewer pins and no serial monitor capability. They are both circular, which is a much easier shape for me to incorporate than the usual rectangular geometries of PCBs. I ordered the Gemma (the Flora is probably a little bigger than I would like for my use), and it is a nearly perfect size for most of my jewellery projects, with the handy JST and USB mini jacks meaning programming and powering the controller is a doddle. However, I am as of yet struggling with the programming – the first example sketch¬† I tried to load onto it would not work (and we’re not talking Blink here btw), because of the lack of a serial monitor. I have not given up on Gemma, but I might have to postpone until my programming knowledge catches up. Another small controller recently introduced by Adafruit is the Trinket, which I have not yet had a chance to consider, but which is supposed to have the processing power of an Arduino Uno and looks really really neat and tiny…

…Which brings us to the last two new arrivals to the wearable controller market of late, the TinyDuino and TinyLily. Born out of a Kickstarter campaign by developers TinyCircuits,¬† these are whole systems of tiny microcontrollers and accessories. Essentially built around the hardware of the Arduino Pro Mini and LilyPad series, the TinyDuino is square in shape and comes with an array of development boards and accessories, while the TinyLily is round and merely the size of my thumbnail but still has 8 sewable ports (4 analogue/4 digital) and two power outlets to play with – plenty for my requirements. The input voltage on these two controllers is variable between 2.7V and 5.5V, so allows for use with a large range of sensors and devices. Here is a size comparison of the Flora, Gemma and TinyLily for reference:

Size Comparison TinyLilyWhile the TinyLily is slightly more awkward to program and connect, it has a definite size advantage over the other two that for making digital jewellery could make all the difference. It is slightly more expensive than the Gemma and about half the price of the Flora, but that seems about right in terms of functionality and processing power. Just for comparison, here are the Trinket, Trinket Pro and Arduino Pro Mini Boards:

Size Comparison Trinket

Sizewise they are perfectly suitable for wearables, especially if you need the advanced functionality and processing power – with Adafruit Neopixels for instance. Their rectangular shape makes them a bit awkward for me, but I could see how they would work in the right situation. Now, on to tackling the programming…