Sigrok Protocol Decoder for the internal protocol of a Rinnai gas heater control panel
Please also see https://github.com/ayavilevich/rinnai-wifi/ for an example of an ESP32 firmware that implements this protocol
Sigrok is a portable, cross-platform, free open source signal analysis software suite
https://sigrok.org/
PulseView is the UI for Sigrok
https://sigrok.org/wiki/PulseView
Rinnai is a Japanese company making gas heaters and other equipment
https://www.rinnai.us/
Rinnai makes various control panels for their devices
https://www.google.com/search?q=rinnai+control+panel
For example
https://www.alpinehomeair.com/viewproduct.cfm?productid=453059509
The control panel is wired over two wires which supply both power and data. This is known as Power Line Communication (PLC).
The decoder decodes the protocol between the MCU and the custom TI PLC chip in the control panel.