I have a Panasonic air conditioner which comes with a wired remote controller CZ - RD513C attched to the wall and has no infrared. I want to make a circuit connecting to STM32F746 to automate the temperature control from the STM display, e.g. set Monday morning 8 am 27°C.
There are two wires coming out of the cable remote controller, one is a ground and the other is a power + signal line. I'm thinking using a circuit like below to control. However, it seems there's a frequency difference problem, the carrier frequency of TDA5051A is 132.5 kHz, but the AC control signal frequency is 18.75kHz. Does anyone have any idea how this could work out?