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GlidePoint Cirque Trackpad with Adapter PCB

Adapter PCB

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.

SPI or I2C

The Cirque trackpad if configured by default for SPI. To use it with the I2C Adapter PCB, you have to remove a resistor (R1).

3V or 5V

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).

Configuration resistor for I2C and 5V

How to remove the resistors

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.

Remove resistor with a solder iron

Clean the solder points with some desoldering wire, to remove the remaining solder.

Clean solder points


Solder the 4pin header to the Adapter PCB.

Soldered 4pin header

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.

Remove plastic spacer

Shorten the pins with the pliers.

Lowered header

Place the Adapter PCB on the oled socket (I2C).

Placed Adapter board on oled socket

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.

FFC cable orientation

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.

FFC cable orientation

QMK firmware support

Add the following lines to your For example qmk_firmware/keyboards/crkbd/keymaps/default/

POINTING_DEVICE_DRIVER = cirque_pinnacle_i2c

To rotate or invert the trackpad add this to your config.h:


To set the diameter of the trackpad add this to your config.h (default is 40):


To enable tap and/or circular scroll add the following to your config.h respectively:


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.