druidus/brompton-electric-ble

This project lets you build a small hardware monitor for a Brompton Electric Mk1 folding e-bike using a cheap ESP32 microcontroller board. The ESP32 connects to the bike over Bluetooth Low Energy, reads its battery charge level, voltage, battery health, and ride statistics, and then sends all of that information to Home Assistant, a popular home automation system, so it can show up on a dashboard or trigger automations. The Brompton Electric Mk1 uses its own private Bluetooth protocol with an encrypted pairing code generated from the bike's frame number. An earlier open-source project figured out how to talk to the bike over Bluetooth but did not connect it to any home automation system. This project builds on that earlier work and adds WiFi and MQTT support so sensors appear automatically in Home Assistant, a keepalive signal so the bike does not fall asleep while charging, and saved Bluetooth pairing that survives power cycles, along with a fuller set of diagnostic readings like battery cycle count and motor distance. Setup involves finding the six digit frame number engraved on the bike, copying a template file to fill in your WiFi and MQTT details along with that frame number, then flashing the code onto the ESP32 board using PlatformIO, a tool for programming microcontrollers. Once running, the ESP32 publishes its readings to Home Assistant automatically, and the README includes an example automation for turning a smart plug off once the battery reaches eighty percent charge. The README notes some rough edges: the bike only accepts one Bluetooth connection at a time, so the official phone app must be unpaired first, some sensor readings are unreliable or return no data at all, and one health reading does not clearly match any obvious unit yet. Several Bluetooth services on the bike remain unexplored. This is a hobbyist hardware project built for a specific bike model, not a general purpose tool.