- individually addressable RGB LED strip
- 9V battery
- battery clip
- 3, 3V coin cell batteries
- 3 LEDs of various colors
- heavy duty foil
Video of crazy me:
Step 1: Helmet
Step 2: RGB LED strip + Arduino
I added a strip of individually-addressable RGB LEDs to my helmet. The LED strip, tutorial, and code can be found on the Adafruit Industries website.
Make sure you cover the strip in tape so that the aluminum foil doesn't short the circuit.
Step 3: stuff the circuit in the helmet
The LED strip is connected to an Arduino that I housed in one of the helmet's horns. I used a 9V battery to power the Arduino. I soldered a barrel jack to a 9V battery clip to make the power connection easy and secure (or you can buy one of these guys).
Step 2: Cuffs
This part is really easy. The LED's positive leg (long leg) needs to touch the positive terminal of the 3V CR2032 coin cell battery, and the other leg is connected to the negative terminal (opposite side). Wrap a piece of tape around the battery and LED legs to complete the circuit and light up the LED.
Here's a great read from Evil Mad Scientists about LED throwies (among other things, the post answers the question, "do I need a resistor?").
Step 2: craft the cuff
I cut out a strip of cardboard, wrapped it in heavy duty foil, and poked the LED through the cuff. I wrapped the LED and battery in tape to make sure nothing got shorted by the foil.