Convert Shelly Gen2 to Tasmota
Disclaimer
You do this at your own risk, if you brick or break your devices, I take no responsibility.
This post contains notes to remind me what I did to convert a Xiaomi Mi Temperature and Humidity Monitor 2 Smart Sensor Bluetooth to Zigbee
Prerequisites
Conversion process
The easiest method is to use the PVVX Telink Flasher. The PVVX Github repository is also available to look at the firmware source code.
References
I originally read about converting these from Bluetooth to Zigbee from the Smarthomescene Blog