Serial comms happen at 9600bd, 5V-TTL, binary.

Protocol Information

Connecting a Bluetooth Module

Connecting a USB-Serial Module

Phone / PC Control software

EBMDisplay can log on Android to CSV Tamas writes:

I've made two Android apps: one for original factory firmware and a very similar but with voltage, ampere, cadence and watts for a slightly modified original factory firmware I call VOAMCA version Therefore they are not for "casainho's" opensource firmware. My Android apps can communicate via Bluetooth and USB Serial module, and all data can be logged into .csv. I've already made graphs in Excel out of such .csv.

it should be clear that my Android apps are compatible with original, or with the VOAMCA firmware versions. I have github pages where I share bluetooth module schematic, VOAMCA firmware code with comprehensive documentation. https://github.com/wptm

My Android apps are not open source, but free for personal use.

Logging Data

Realterm can log raw data on a PC

EBMDisplay can log on Android to CSV

Graphing Data

Updating Firmware

STM8/32 have a bootloader rom that can update formware through the serial port AFTER it has been enabled using the SWIM/Programmer. Bootloader runs at 115kbd