The Adapter PCB can be used on any keyboard with a I2C oled display connector like the CRKBD, Lily58, or Kimiko.
The Adapter PCB has two 4.7k pull up resistor for I2C, to make it split keyboard compatible with serial communication.
The Cirque trackpad if configured by default for SPI. To use it with the I2C Adapter PCB, you have to remove a resistor (R1).
You can power the Cirque trackpad by default with 2.5-3.6V and use it for example with a SparkFun Pro Micro RP2040. To use a 5V controller, you have to remove two resistors (R7, R8).
You can use a hot air gun to remove the resistors. Be careful to not melt the FFC connector.
To use a solder iron to remove the resistor, put some solder on the tip. Touch the resistor sideways with the solder iron tip and push it carefully aside.
Clean the solder points with some desoldering wire, to remove the remaining solder.
Solder the 4pin header to the Adapter PCB.
If you use low profile sockets for you controller like the Mill-Max Series 315, remove the black plastic and shorten the legs with your pliers. This way you can mount the Adapter PCB low as possible.
Lift the plastic carefully with the pliers.
Shorten the pins with the pliers.
Place the Adapter PCB on the oled socket (I2C).
Lift the black part of the FFC cable connector and insert the cable with blue part facing up.
The FFC/FPC cable is a 12 position with 0.5mm pitch.
If you're using a holder from @bom_tarnes place the trackpad on the holder first. Note that the holders are currently designed for the 40mm curved trackpad.
Then insert the cable into the trackpad. The blue part on the cable must be facing to the black dot on the cable connector.
Add the following lines to your rules.mk
. For example qmk_firmware/keyboards/crkbd/keymaps/default/rules.mk
POINTING_DEVICE_ENABLE = yes
POINTING_DEVICE_DRIVER = cirque_pinnacle_i2c
To rotate or invert the trackpad add this to your config.h
:
#define POINTING_DEVICE_ROTATION_90
#define POINTING_DEVICE_INVERT_X
#define POINTING_DEVICE_INVERT_Y
To set the diameter of the trackpad add this to your config.h
(default is 40):
#define CIRQUE_PINNACLE_DIAMETER_MM 40
To enable tap and/or circular scroll add the following to your config.h
respectively:
#define CIRQUE_PINNACLE_TAP_ENABLE
#define POINTING_DEVICE_GESTURES_SCROLL_ENABLE
Check the QMK docs for more settings.
Compile the firmware qmk compile -kb crkbd -km default
and flash the hex file with QMK Toolbox.
The Adapter PCB is made by @bom_tarnes and is open source.
Inspired by beekeeb and his build guide.