Integrate Electric Unicycle Battery Charging

[corbanmailloux]

In order to preserve the battery on my unicycles, I'd like to not keep them fully charged until I'm going out to ride them. The available apps don't let me set a max charge level, but they do expose the current charge over BLE for the apps to consume.

Idea:

• [ ] Put the unicycle charger on a smart switch, ideally with current monitoring for additional calculations later.
• [ ] Build a custom ESP device (hopefully as a custom sensor in ESPHome) that can connect to the wheel and extract battery level.
  • Reference: https://github.com/Pickelhaupt/EUC-Dash-ESP32/blob/master/src/hardware/Kingsong.cpp
• [ ] Monitor charge level and turn off the charger accordingly.

[corbanmailloux]

Alright, well I played with this for a while, but I'll need to write more custom code than I feel like for tonight. Dropping a bunch of references:

• https://github.com/esphome/esphome/blob/dev/esphome/components/ble_client/sensor/ble_sensor.cpp
  • I could implement my own BLE sensor type, similar to the text or standard BLE sensor. This would probably be the best option moving forward.
• Good code references for which service/characteristic I need, and how to parse them:
  • ESP32 code:
    • https://github.com/Pickelhaupt/EUC-Dash-ESP32/blob/master/src/hardware/Kingsong.cpp
    • https://github.com/Pickelhaupt/EUC-Dash-ESP32/blob/2650400ce4a9156fc71b01028981d66c447dede1/src/hardware/blectl.h#L65
  • Java for WheelLog:
    • https://github.com/Wheellog/Wheellog.Android/blob/master/app/src/main/java/com/cooper/wheellog/utils/KingsongAdapter.java#L21
    • https://github.com/Wheellog/Wheellog.Android/blob/291b473e4e56f504eb917985b3a6ffbdf2000da9/app/src/main/java/com/cooper/wheellog/utils/Constants.java#L30
• There's also a custom component that helped a bit in my testing:
  • https://github.com/myhomeiot/esphome-components#ble-client
  • Example: https://github.com/myhomeiot/esphome-components/blob/main/examples/myhomeiot_ble_client/mi_band.yaml
• Forum about reverse engineering the protocol: https://forum.electricunicycle.org/topic/870-gotwaykingsong-protocol-reverse-engineering/

[corbanmailloux]

Branch with ESPHome config: https://github.com/corbanmailloux/home-assistant-configuration/compare/unicycle-monitor

[olijouve]

Hi, did you finally succeed? I would also like to be able to stop the load on my wheel at say 90% so I am interested in your work...