Crkbd with Pimoroni Trackball

Portable keyboard and mouse companion.

This was inspired by foureight84's sofle and vlukash

Materials

Build

I won't go over the details of the crkbd base build there is a lot of youtube clips and the orginal foostan build is detailed.

The only thing special is I used the sparkfun pro micro usb-c controller and qwiic port to connect the pimoroni trackball, shown below.

Qwiic Connection

Pimoroni Trackball with qwiic connection:

Trackball connected to the controller:

Controller connected to the board:

Right Hand Master:

QMK firmware

I'm in no means a pro C/C++ developer and I'm sure once you see the code you could probably find improvements, but most of the development was originally from foureight84, drashna and sevanteri.

Currently the common crkbd doesn't support i2c for the split keyboard communication, so I had to build the firmware similar to vlukash trackpad approach by having a firmware for the right and left controllers. Basically the master hand, the one that has the usb connected, will have the working code for the pimoroni trackball. So you have to explicitly say which is the master and enable the pimoroni trackball for that side only.

The firmware does not include the OLED driver mainly because I haven't tested it yet. The LED in the trackball will change indicating which layer you are currently at.

Clone my firmware here: https://github.com/greyhatmiddleman/qmk_firmware.git

git clone --branch greyhatmiddleman https://github.com/greyhatmiddleman/qmk_firmware.git

The firmware is located in keyboards/crkbd/rev1/common/keymaps/greyhatmiddleman_trackball_[left|right].

Firmware Customization

For this example the trackball will be connected to the right hand which will be the master side.

Here you want to make sure the following:

Important: Make sure that both the config.h and keymap.c are identical under the right and left folders
In the config.h file make sure to define the master:

...
#define MASTER_RIGHT
...

Change your keymaps accordingly, no need to change the code under pointing_device_task, unless you added layers or change the names of the layers.
Set the rules.mk based on the which hand is master and that has the trackball connected.
For the right hand rules.mk set the following:

...
PIMORONI_TRACKBALL_ENABLE = yes
...

For the left hand rules.mk set the following:

...
PIMORONI_TRACKBALL_ENABLE = no
...

Verify all your changes and confirm that the config.h and keymap.c are the same in the right and left holders.
Now you ready to flash the firmware.

Flashing Firmware

Connect the usb to right hand controller and run the following:

qmk flash -kb crkbd/rev1/common -km greyhatmiddleman_trackball_right

Next connect the usb to the left hand controller and run the following:

qmk flash -kb crkbd/rev1/common -km greyhatmiddleman_trackball_left

Connect the usb to the right hand and your computer and you should be all set!

Troubleshooting

Confirm that the config.h and keymap.c are the same under the right and left folders.
Ensure that you connected the trackball to the master hand, which would be defined under the config.h
The rules.mk should be different between the right and left folders. It should dictate which has the Pimoroni enabled which the other side should have it disabled.

Future Improvements

Convert the controllers using the Nice!Nano ones for wireless connectivity
Add an OLED on the opposite side of the trackball
Try to get EE_HAND working so that we can have a single firmware

vrinek/crkbd-pimoroni-trackball