So this is my take on the BlinkM LED module, with instruction taken from the most excellent “Ghetto Pixels” instructable from jimthree . Not bad for 5 mins of tinkering and a few £’s worth of parts.
For those unfamilliar with it, the BlinkM is a uC, paired with a RGB LED. The uC accepts commands over I2C, from a master controller (in this case, an Arduino MEGA2650), and sets the appropriate PWM values for the 3 LED elements, in order to acheive colour modulation. It’s a lovely concept, but the offical BlinkM modules sell for £10-£12(!), which is far too rich for my budget. However, the design is open sourced, which has led to the development of what you see above, with a parts cost of approximately £2 per node (without LED) in volumes of 25+. That’s much more palletable.
Using this idea, I want to see how far I can push the distance over which the I2C bus can function. I2C was originally designed to allow communication between IC’s on the same circuit board. It doesn’t function so well over long distances, but there are a few ideas on the web that try and tackle this problem. I’ll post up some more when I get around to playing with them.
That’s all for now, folks!