Cirque Trackpad i2c on Corne Keyboard Build Log
The trackpad is the Cirque GlidePoint® Circle Trackpad 23mm TM023023 with flat loverlay (MPN TM023023-2024-002).
SPI and I2C
If you ordered the I2C version, you should skip this section. From the specification, when R1 (470 ohm) is installed, it configures the devices for SPI operation. When R1 is not installed, it’s for I2C. So, I’ve desoldered the R1 from the trackpad.
If you can power it with 2.5-3.6V, you can skip this section. The type-c breakout board runs at 5V. So we cannot directly power it directly. We can probably use a logic level shifter and voltage regultor to provide 3.3V. Alternatively, according to the post on Cirque Forum, the trackpad can run at 5V when R7 and R8 are removed.
The above photo shows the trackpad with R1, R7 and R8 removed.
When I use a hot air rework station, I melt it. For the second try, I use a soldering iron to remove the resistors.
On the crkbd board, the OLED pins provide VCC, GND, SDA, and SDL. We can connect them to the VDD, GND, SDA, SCL pins through a breakout board and a 12P 0.5mm FFC/FPC cable.
If you have the bigger version, there might be test points on the trackpads. So it might be easier than a breakout board.
The crkbd uses serial to connect the left and right halves. So we need to add two 4.7k pull up resistor for I2C.
As of Jun 30, 2022,
develop branch is required. I’ve used the
develop branch at 01bc974365581da6563e2bbd2425233d97280fdd
#define SPLIT_POINTING_ENABLE #define POINTING_DEVICE_RIGHT #define POINTING_DEVICE_ROTATION_90 #define MASTER_RIGHT
POINTING_DEVICE_ENABLE = yes POINTING_DEVICE_DRIVER = cirque_pinnacle_i2c
You might need to disable some features if the firmware size is too large.
Here is a compiled firmware with VIA, RGB and cirque trackpad support. OLED support is disabled.
Similar to the holder at Kyria with Cirque circle trackpad on Reddit, a mount can be added onto the crkbd OLED cover.
The STL is released under CC BY 4.0 at https://www.thingiverse.com/thing:5425081
A Tiny Breakout Board
The green breakout board is too big to be used with a case. So, I’ve made a small version.
For tapping to work, the side with the trackpad has to be used as the master side.
Ananse#4070 mentioned on the discord channel
https://github.com/qmk/qmk_firmware/blob/8fa7b62011484f078548535556e91494a7f6cb8d/quantum/pointing_device_drivers.c#L134 the button press gets cleared otherwise its seen as being held down. So what happens is when the cirque is not on the master side this happens before the master recives the report and it doesn’t register the click
Thank you to the buyer of this keyboard and the helpful people on the QMK discord channel.
The pre-assembled trackpad with a custom ergonomic mechnical keyboard can be purchased at https://shop.beekeeb.com/product/cirque-glidepoint-circle-trackpad-for-split-keyboard/
GLIDEPOINT is a trademark of Cirque Corporation.