CTC-GSi-8---Homeassistant

For connection between CTC GSi and Homeassistant (testet with GSi 8 and GSi 16)It probably works on EcoHeat 400 series as well. I haven't found all the modbus registers yet from the lists in the pdf files

Skærmbillede 2022-11-07 151830

RJ12 cable cut in half an connected to NodeMCU ESP32

Pinout for the RJ12 cable connected to the display of the CTC heat pump

image-png-Jun-29-2022-09-29-07-52-AM

1: GND

2: 5V

3: Not used

4: RX GPIO 16

5: Flow control pin GPIO 5

6: TX GPIO 17

Skærmbillede 2022-11-07 152704

Using Esphome it is possible to read and write modbus.