pico-uart-decode/rovsun-tcl-esphome

rovsun-tcl-esphome is a project for people who want to control a ROVSUN mini-split air conditioner or heat pump locally, without relying on the manufacturer's Wi-Fi app or cloud service. It replaces the original Wi-Fi module inside the unit with an ESPHome based board, specifically the SMLIGHT SLWF-01PRO, so the appliance can be controlled directly through Home Assistant instead. The project's core is a decoder for the serial communication protocol the appliance uses internally, which the maintainer figured out by capturing real signals from the wire between the appliance and its original module using an oscilloscope. That decoded protocol handles things like power, cooling, heating, drying, and fan modes, fan speed settings, target temperature between 16 and 31.5 degrees Celsius, and airflow direction settings. Only one specific hardware setup, the SLWF-01PRO version 2.1 board wired to a particular ROVSUN unit, has actually been tested on real hardware. Other parts of the code are based on the captured protocol and tested in software, but not confirmed on physical equipment, so the README warns strongly against assuming another similar air conditioner model uses the same wiring or protocol details. Setup starts in a safe, read only mode called poll-only, which listens to the appliance's status replies without sending any control commands, letting you confirm the wiring and communication work before enabling actual control. Only after that verification step do you switch to the full control profile. The system is designed to fail safely: it will not send commands unless it has a recent, valid status reading from the appliance, and it refuses to guess when it receives a signal it does not fully recognize. Because this involves opening and rewiring a mains powered appliance, the README includes a clear safety warning about disconnecting power and verifying the unit is de-energized before any work begins. The project requires Python, a C++ compiler, and ESPHome to build and test, and includes an automated verification suite that checks the code against real captured data.