I have a air conditioner that has a header on the mainboard that various optional (expensive) addon communications modules can connect into eg wifi
I am wanting to see if I can connect to this port and control it over serial or similar once I determine what protocol it is using. RS232?, RS485?
I have been trying to determine what protocol this port uses to communicate with the addon modules that can be plugged into it and what the correct connections are. Once I have determined the correct pins and protocol I should be able to write a script that will do the communication.
I have done some research and probing with multimeter (I don't have an oscilloscope currently
) and located a circuit diagram for the header on the mainboard (attached),
What i have determined so far:
Pin 1 0v - possibly rx?
Pin 2 5v - possibly tx?
Pin 3 5v - possibly tx?
Pin 4 12v
Pin 5 Gnd
I was wondering if anyone has any suggestions or pointers on what I could try to work this out?
I'd be more likely to guess I2C, especially if more than one device can be attached/chained off that. You're more likley to figure it out if you actually have one of those add-ons and some method of monitoring the obvious data lines (pins 2 and 3).
You've committed the classic sin of failing to give us basic information that you have, such naming/linking the brand and model info on the air conditioner and the add-ons you're trying to emulate. That severely limits the ability of anyone to acquire the answer for you.