This repository contains some proof of concept code for talking to the Logitech G710 mechanical keyboard.

Working

G1-G6 key events
M1-MR key events
Media key events
M1-MR per key backlight - events, read, write
WASD/other keys backlight - events, read, write
'Game mode' - events, read

Known issues

Game mode is not writable (I'm missing something...)

Won't fix

Macro recording, Logitech drivers do it in userspace

Protocol

Key events
- All key events are sent from interface 1, endpoint 130
- G1-G6 keys send numbers 1 to 6 by default, stop by writing to control 0x0309
- Media key send interrupts in the format of 0x02 [bitmask]
- Other keys send interrupts in the format of 0x03 [G keys bitmask] [M keys bitmask] [backlight / game mode bitmask]
- See keymap in g710.py for details
Control values
- All control values return their ID as the first value
- 0x0305 - read: 0x05 [game mode] 0x19 0x49 0x51 0xff 0xff 0xff. Writing doesn't change the game mode.
  - TODO meaning of other values unknown
- 0x0306 - read/write 0x06 [M keys bitmask] - sets backlight for M keys
  - Bitmask values: 0x10 - M1, 0x20 - M2, 0x40 - M3, 0x80 - MR
- 0x0307 - read/write 0x07 [WASD value pair] [other value pair] - sets backlight
  - Value pairs for default backlight levels:
    - 0x00 0x20
    - 0x8f 0x11
    - 0xdf 0x07
    - 0xdf 0x01
    - 0x00 0x00
  - Writing backlight this way resets buttons to some random(ish) setting
    - TODO investigate
- 0x0308 - read/write 0x08 [WASD backlight level] [other backlight level] 0x00 - backlight levels
  - Backlight levels are 0-4, 0 being the brightest
  - Last value likely unused
- 0x0309 - read/write 0x09 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 - disables ghost input on write
  - Values likely unused
  - TODO what are valid values?
- 0x0380 - unknown, seems to read zeroes