firmware_notes.md

Firmware and Keymap Notes

Flashing Firmware For Wireless Builds

• See the ZMK documentation on how to flash the firmware binaries to your keyboard.
• The default firmware binary files are located here, and are named zmk_left.uf2 and zmk_right.uf2.

Default Keymap

Mercury's default keymap seeks to achieve the following goals:

• All keyboard shortcuts should be accessible
• Reduce the use of the outer pinky columns
• Minimize the learning curve, especially:
  • Minimize the need for user-tuning of timing parameters (tapping-term)
  • Minimize the requirement for strict key-up order

To achieve these goals, we use several combos

Modifier combos

1. K + L -> Right Shift
2. S + D -> Left Shift
3. D + F -> Number Layer
4. S + D + F -> Shifted Number Layer
5. A + Function Layer -> Shifted Function Layer

Other combos

1. X + C -> Tab
2. C + V -> Esc
3. M + Comma -> Caps Lock
4. H + J -> Menu Key (opens the context menu, similar to Right Click in Windows)
5. Q + W + E -> activate System Layer for the next keypress

Bluetooth

• After flashing the firmware, you will likely need to follow the settings reset procedure described here to get the two keyboard halves to bond to each other, and to get the keyboard to pair with your computer.
• There are three Bluetooth profiles that can be used to pair with three computers. To select a specific profile, activate the System Layer, then press Bt1 / Bt2 / Bt3 (left thumb cluster).
• To clear a Bluetooth profile so that it can pair with a different host, activate the profile you wish to clear. Then activate System Layer, and press BtClear (C key).
• By default, the keyboard will always prefer to send output to USB when a USB cable is connected. If you want to send output over Bluetooth while chargin your keyboard over USB, you will need to enable Bluetooth-preferred output. To do this, activate System Layer, then press Bluetooth (B key). To enable USB-preferred output isntead, activate System Layer, then press USB (S key).