[March 2013] I was at a rave Wreck beach last night and for some reason there was a shopping cart down there. It could be debris from the 2011 Japanese Tsunami. It was a plastic shopping cart with a hexoganal (honeycomb) basket. I started thinking about how amazing it would look if each of the cells were lit up by RGB LEDs. When I got home (after being chased off the beach by a police helicopter), I designed an LED PCB to fit the shopping cart.
The board uses WS2803 LED driver chips. A WS2803 can drive 18 PWM channels up to 30 volts (6 R,G,B channels). To make sourcing parts easy I’ll use a 12v car/rv/boat battery, so each cell needs to run at 12v. This means 3 3v Blue in series, 3, 3v green in series, and 4,2v red in series. This means 9-10v per series group. If I go all the way to 12v the LEDs won’t work when the battery goes down to 11.9v due to the low operating voltage range of LEDs.
I CNC’d and populated the circuit boards the next day. They work very well.