// MCUs are flipped on each side, relative to the shape of the case,
// but for ease of mounting, the pinout is not flipped with the controller.
// The same finger on each hand uses a column connected to the pin with the
// same silk-screen label on each Pro Micro.
// Pin use:
//
// MCU | Silk | DMOTE
// -----+------+----------
// D3 | TX0 |
// D2 | RX1 |
// D1 | 2 | LED strip input (dominant half only)
// D0 | 3 | Serial interface between halves
// D4 | 4 | Outermost pinky-finger column
// C6 | 5 | Column
// D7 | 6 | Column
// E6 | 7 | Column
// B4 | 8 | Column
// B5 | 9 | Outermost index-finger column
// -----+------+----------
// F4 | A3 |
// F5 | A2 |
// F6 | A1 | Top row (furthest from user)
// F7 | A0 | Row
// B1 | 15 | Row
// B3 | 14 | Row
// B2 | 16 | Row
// B6 | 10 | Bottom row (closest to user)
// WS2812 RGB LED, normally used to indicate keyboard state: