keychron_qmk_firmware/keyboards/handwired/splittest/bluepill

bluepill splittest

This is the splittest example for the bluepill MCU. To trigger keypress, short together pins B10 and B1.

Keyboard Configuration

The type of communication (bitbang, serial (half/full duplex)) is set by the keymap config.h file with variables with SPLIT_ prefix. So this example uses:

• config.h to set which SDI to use for serial. Either define USE_SDI1_ON_STANDARD_ROLE_PINS, USE_SDI1_ON_ALTERNATE_ROLE_PINS or USE_SDI2 before the #ifdef that configures the default case when none of these variable is defined.
• post_config.h for defining the communication pins between the halves once the keymap is configured.

On your keyboard, you most likely will only use config.h because you'd have already chosen your communication scheme: serial type, SDI, pins.

Wiring

Switches

• Add switches to both Bluepills across B10 and B1 pins

Handedness

Have a look at the handedness documentation

• Add pull-up resistor to left side between VCC and A7
• Add pull-down resistors to right side between GND and A7

Send power to the other half

• Connect the following pins on both sides together: GND, VCC

Halves data connection

Choose one of the connection type

serial - bitbang

• Connect the B8 pins on both sides together

serial - usart half duplex

Check the documentation to determine the pull-up resistor.

• To use the default usart (USART1) with the standard role pins,
  • Connect the A9 pins on both sides together and to add a pull-up resistor on one of these pins
  • Define USE_SDI1_ON_STANDARD_ROLE_PINS in config.h
• To use the default usart (USART1) with the alternate role pins,
  • Connect the B6 pins on both sides together and to add a pull-up resistor on one of these pins
  • Define USE_SDI1_ON_ALTERNATE_ROLE_PINS in config.h
• To use the usart2 (USART2) pins,
  • Connect the A2 pins on both sides together and to add a pull-up resistor on one of these pins
  • Define USE_SDI2 in config.h

serial - usart full duplex

• To use the default usart (USART1) with the standard role pins,
  • Connect the mpins on A9, A10 one to the other on each side
  • Define USE_SDI1_ON_STANDARD_ROLE_PINS in config.h
• To use the default usart (USART1) with the alternate role pins,
  • Connect the pins B6, B7 one to the other on each side
  • Define USE_SDI1_ON_ALTERNATE_ROLE_PINS in config.h
• To use the usart2 (USART2) pins,
  • Connect the pins A2, A3 one to the other on each side
  • Define USE_SDI2 in config.h