The idea of this repo is to make fridges smart so you can enable Super mode when sun is out and PV is running high so the compressor will cool everything to the max and then turn it off when sun is low or you dont want to get disturbed by noises while watching Netflix and the fridge is just around the corner.

In my case the fridge models are Siemens KG39EAI40 and Bosch KGE392I4P which seem to be more or less identical. At least the PCBAs are, part Number Bosch Siemens 752243.

Basically there is a PIC16F1823 sending commands to the brain wich is a NEC D78F0524. The PIC converts pressed touch fields to commands which consist of 35byte Blocks with 19200bd/s. There is only one data line, no clock. While the door is open, the PIC keeps sending those 35byte (19ms) blocks with 82ms pause between each block.

There is a non-linear SOT-23 SMD Hall Sensor which acts like a reed switch, 5V when the door is open, 0V when closed. Problem is, you can communicate only when the door is open, so either you read the signal with your ESP and then forward or minupulate it, or you install an OR gate.

Switches:

Sensors: