WS2812B light signal - CPU Board

Board to run colorchord2 on a string of WS2812B LEDs with live line-in audio.

Errata (Rev 01)

Opamp inverting / non-inverting inputs are swapped
- Workaround: Lift pads 2 and 3, and 5 and 6, and connect them crossed using magnet wire.
Opamp is not rail-to-rail and does not allow to use the ADC in full range
- Workaround: Only use limited range -640 to 520.
LED footprint is wrong.
- Workaround: Flip 180 degrees and solder shifted onto the right pads, then use magnet wire to connect the remaining two pads.
Serial boot loader non-functional (uses incompatible UART I/Os).
- Workaround: Program via JTAG / SWD.