Look:
The final design follows the original idea closely. The costume is a whole-body suit from a black stretchy fabric. On it are 50 Neopixel LEDs, that are organized in 5 chains (one chain for each arm and leg, and one chain for the torso.) The neopixel are capaple of emitting RGB colours but we decided to use white light to contrast the black of the suit. The pixels are placed on silver diamond shaped pads that should underline the light.
The wearer of the costume can make the lights blink by moving. The costume has 5 stretchsensors placed at the elbows, the armpits and the back, as well as 2 pressure sensors placed at the knees. If the 2 stretch sensors of an arm are stretched at the same time (so if the arm is stretched in an upward direction) the LEDs on this arm will light up.
If both arms will light up simultaneously the center chain of LEDs, located on the upper body, will also light up. If the pressure sensor is pressed the LED-chain of the accompanying leg will light up. Also if both pressure sensors are pressed simultaneously the torso chain will light up as well.
By lighting up, we mean that 3 LEDs in the chain will light up in a flowing fashion. So first the LEDs at the sensor will light up, and the light will move towards the center of the body.
Hardware:
We use Neopixels, because they are smart chainable LEDs. One can programm a chain of neopixels to repeat a pattern. Each chain needs one output pin of the Lilypad. Each sensor uses one input-pin of the lilypad. The stretchsensors use analog input pins, while the pressure sensors can work with digital input pins. The lilypad and the chains are powered by two battery packs with three AA batteries each.
Code:
The code implements a very simple learning algorithm to determine the threshold at which the stretch sensors count as stretched. We continously measure all values (the resistance provided by the sensor) and memorize the highest and lowest value for each sensor. With these values we determine a range, in this range the upper or lower 30 % of values count as the sensor being stretched.
The pressure sensors close a circuit if pressed and so it is easily determined if they are activated.
