Over the weekend I finished up the power wiring for the suit and did tests with the suit running exclusively off battery power. The astonishing part is just how much energy 250 RGB LEDs can use. This table shows LED color (in HTML #rrggbb format) with corresponding power consumption in amps and watts. A dim color (like #010000, which is the dimmest possible red) will use less energy than a bright color (like #ff0000, the brightest possible red). Using more than one of red, green, and blue, also uses more energy. The most energy consumption comes from #ffffff, which is the brightest white the LEDs can produce. Sadly my batteries can’t put out enough power for me to run the suit that bright.
|#000000||0.18||1.4634||No light – power consumed by LED driver chips|
|#FF0000||5.43||44.1459||Maximum brightness red|
|#00FF00||5.36||43.5768||Maximum brightness green|
|#0000FF||5.35||43.4955||Maximum brightness blue|
|#7F7F7F||7.81||63.4953||Half brightness white, as much as my batteries can handle|
So at half-brightness white, my suit pulls an amazing 8 amps at 8.13V, or about 64 watts. More than a standard 60-watt lightbulb. Fortunately the suit makes more light than a dinosaur incandescent lightbulb, plus can generate any colors I want and animate at 40 frames per second.
I’m currently constructing the final circuit board that mates the daughterboards (XBee, Bluetooth, and micro-SD reader) to the Arduino Mega. That will probably be done by Wednesday.