sabik-cpu/README.MD

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# WS2812B light signal - CPU Board
Board to run [colorchord2](https://github.com/cnlohr/colorchord) 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.
* Missing level shifters for WS2812B LEDs (RX)
* Workaround: Don't use WS2812B RX inputs on the board
* Missing level shifters for WS2812B LEDs (TX)
* Workaround: The first LED will kinda sorta do the level shifting for you, but sometimes fail to display correctly. Just ignore its erratic blinking.