Updated: Jun 5
The unibody ThumbsUp! keyboards support ProGlide Cirque touchpads.
Cirque touchpad fits nicely under the top PCB and are not visible from outside, so here its picture sticking out, not yet glued to the top PCB:
There are tracks leading to a connector on the top board.
(Add it to the order and let me know if you want the connector to be installed, provided I have them in stock.)
You'd need to buy these two parts from Mouser (or any other vendor):
Mouser #: Mfr. #: Desc.:
355-TM0400402024-301 TM040040-2024-301 Capacitance Touch Sensor Modules Capacitance Touch Sensor Modules 40mm Round SPI/I2C adhesive overlay
538-15166-0125 15166-0125 FFC / FPC Jumper Cables FFC / FPC Jumper Cables FFC 0.50 Type A 12 ckts lgt 127
Touchpads need to be modified:
R1 needs to be removed to use I2C the boards support:
For the ProMicro and Atmel32U4-based keyboards the touchpad also needs to be made to work with 5V power. For that remove R7, R8 from the touchpad.
RP2040 boards use 3.3V so for them no modification is required.
UPDATE 2023-04-17: With the default QMK settings the mouse pointer may jitter a bit. Put this line into config.h to stabilize it:
#define POINTING_DEVICE_TASK_THROTTLE_MS 10