After I searched some, I think its similar to this hayward pool heater (same code for board and same NET wire. It seems that the pcb sends info about temps all the time, and the screen/controller sends its parameters when they are changed). [résolu] Reverse engineering protocole thermopompe hayward
GitHub - njanik/hayward-pool-heater-mqtt: A sketch to control an Hayward pool heater via MQTT
Though those does not work for my heater. After that I probed with an analyzer, and Im pretty sure I can read at at least temp in and out (just by decoding it with uart). But something weird is happening with the controller, it seems like controller sends either at different baud or some different protocol.
When I change some parameter with the screen It seems that the controller send it and pcb anwers, and it happens 3 times.
But when I zoom in, it seems that they are not nearly the same.
