Working with Lilypad Arduino is something I’ve wanted to try for a while now – but simply haven’t found the time! Knowing that BarCampGeelong was only a few weeks away spurred me into action. First, I read up on the Lilypad Arduino tutorials from Leah Buechley. Running Ubuntu, I had already installed the Arduino IDE from the software manager, so I was good to go.
So, what sort of project was simple enough to allow me to get the hang of this new technology while still presenting enough of a challenge to be interesting? I decided on a scarf that would detect light levels, with the aim of turning on some bright white LEDs if light levels were too low.
First, I needed a scarf. I decided on this Dropped! lace openwork pattern so that the components could be sewn in with conductive thread and not look out of place. I also thought about what type of material to make the scarf out of – in case any of the electronic components overheated and melted or caught on fire. I chose a 98% wool blend – ‘Beulah’ by Sean Sheep – nice and cheap too in case the project didn’t work out.
Next, I needed some Arduino Lilypad components – which are now available in Australia from Little Bird Electronics. For this project, I used;
Then, I needed some Arduino code to read in the light sensor and do the logic for turning on the LEDs – you can get the code from my page on GitHub
. Once the Arduino board was programmed, it was time to sew in the components with conductive thread. It was here that some problems arose. My original plan was to have 5 LEDs on the scarf, which all lit up at the same time. When sewing the conductive thread, I found that I could only sew in one LED to the -tive terminal (ground) petal on the Lilypad Arduino.
NOTE: Andy Gelme (@Geekscape) has since given me some advice on working around this, by finding alternative methods to ground the LEDs. I just haven’t implemented it yet!
The other problem was that due to the openwork design of the scarf itself, some of the conductive thread was prone to crossing – which meant that the circuit didn’t work as designed. I unpicked the thread and it was resewn, with care given to making sure the wire did not cross.
The presentation given to BarCampGeelong can be found on Slideshare here;