The ball is the trackball

This is Arduino code and 3D-printable models for a Bluetooth trackball in which all the electronics are inside the ball.

Demo video.

Blog post.

It runs on Adafruit's Feather nRF52840 Sense and uses the accelerometer, gyroscope and magnetometer data with a sensor fusion algorithm to get the ball's orientation. When you rotate the ball, it moves the mouse cursor accordingly.

TODO:

• whitelist advertising to only allow connections from bonded devices unless the user requests pairing mode
• go to sleep after a period of inactivity and wake when moved
• OTA firmware updates