Another idea: with time and patience a video camera might be able to capture images of the serial waveform from your analog oscilloscope. On Sat, Oct 10, 2015 at 11:47 AM, wrote: >> > Celair Evaporative >> > > Aircondioner. >> > >> >> I have never seen a Celair device. >> This appears to be a manual for such - worst case you should be able to = make >> a controller of your own based on this - something to be avopided if pos= sible >> :-) >> >> http://www.celair.com.au/core/general/pdf/manual.pdf >> >> 4 wire cable MAY be ground/supply/ & ground referenced tx rx. >> Probably not but your scope should tell you. > > That would be my initial suspicion for transmission system as well. > > If the PCB can be removed from the control unit, it may be possible to ey= eball where the various pins connect to and then look up the micro data she= et to get a feel for what the signal transfer format may be, if the pins ha= ve a UART as an option then a serial protocol would be a good starting bet. > > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 Jason White --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .