Link to actual code in this repo
App is work in progress, but an earlier version is released on the Google Play Store for my friends.
The goal is a strength sport training log app with a Bluetooth LE enabled sensor for the barbell (ARM Cortex M0, custom PCB and firmware) for automated rep counting (first goal already done) and bar speed and path estimation (second goal wip) in 3D space with 6D accelerometer and a Bosch BMP380 barometric pressure sensor fusing with kalman filter state estimation.
the work in progress firmware is located here: link to Firmware Repo