Bluetooth

Bluetooth Known Supported Hardware

Currently Bluetooth support is limited to AVR based chips. For Bluetooth 2.1, QMK has support for RN-42 modules. For more recent BLE protocols, currently only the Adafruit Bluefruit SPI Friend is directly supported. BLE is needed to connect to iOS devices. Note iOS does not support mouse input.
Board
Bluetooth Protocol
Connection Type
rules.mk
Bluetooth Chip
Roving Networks RN-42 (Sparkfun Bluesmirf)
Bluetooth Classic
UART
BLUETOOTH = RN42
RN-42
Bluetooth Low Energy
SPI
BLUETOOTH = AdafruitBLE
nRF51822
Not Supported Yet but possible:

Adafruit BLE SPI Friend

Currently The only bluetooth chipset supported by QMK is the Adafruit Bluefruit SPI Friend. It's a Nordic nRF5182 based chip running Adafruit's custom firmware. Data is transmitted via Adafruit's SDEP over Hardware SPI. The Feather 32u4 Bluefruit LE is supported as it's an AVR mcu connected via SPI to the Nordic BLE chip with Adafruit firmware. If Building a custom board with the SPI friend it would be easiest to just use the pin selection that the 32u4 feather uses but you can change the pins in the config.h options with the following defines:
  • define AdafruitBleResetPin D4
  • define AdafruitBleCSPin B4
  • define AdafruitBleIRQPin E6
A Bluefruit UART friend can be converted to an SPI friend, however this requires some reflashing and soldering directly to the MDBT40 chip.

Bluetooth Rules.mk Options

The currently supported Bluetooth chipsets do not support N-Key Rollover (NKRO), so rules.mk must contain NKRO_ENABLE = no.
Use only one of these to enable Bluetooth:
  • BLUETOOTH_ENABLE = yes (Legacy Option)
  • BLUETOOTH = RN42
  • BLUETOOTH = AdafruitBLE

Bluetooth Keycodes

This is used when multiple keyboard outputs can be selected. Currently this only allows for switching between USB and Bluetooth on keyboards that support both.
Name
Description
OUT_AUTO
Automatically switch between USB and Bluetooth
OUT_USB
USB only
OUT_BT
Bluetooth only
Last modified 1yr ago