I am trying to decode a reverse cycle split system air-conditioner comms signal so that I can control an outdoor a/c compressor unit without using the manufactures indoor unit. The unit is made by Midea and they seems reluctant to share their protocol details.
I used my oscilloscope to look at the data and used the default serial decoding settings to get some HEX data strings.
I took some more data when the indoor unit was requesting cooling but I don't know if my acquisition settings right. Here is some data recorded of packets taken every 40seconds or so before the indoor unit requests cooling, during cooling request and after.
I know that the indoor unit is receiving temperature measurements so that the system can decide at what speed to run the compressor. Not sure if it is temperature measurements that are communicated to the outdoor unit or if it is VSD speed commands. If it is temperature measurements then there should be data that is reducing during the cooling call data block.
I am looking for any advise as to how I should go about decoding this data. Should I buy a serial decoder instead of using my oscilloscope? I am probably out of my depth, but I love a challenge. Any advise greatly appreciated.