I am working on an arduino project that will interface with an iPonic 624 greenhouse controller. This controller does things like turn on humidifier, open vents, etc, based on outside temp/humidity.
There are two outside temp/humidity sensors: Here is a picture of one. You will notice the four wires Red, Black, Green, White.
From looking at the controller main board, the temp/humidity sensors wire into terminal blocks like this:
Both black leads > shared GND Both red leads > shared + Both white leads > shared CLK Room 1 green lead > DAT1 Room 2 green lead > DAT2
Here is picture of the Iponic greenhouse controller main board:
I have researched different methods to snoop the communication going over these pins, such as turning on the device and looking for voltage on bootup. Or using a proper logic analyzer, or maybe using a USB to UART analyzer. I could toy with unplugging the sensors easily and replug them in to see if they re-establish communication.
I have used TCPDUMP to analyze lots of TCP/IP network traffic, but never anything like this :)
Can anybody give some tips on where to start?
Is it easy for any of you to see by looking at the images if you suspect it is UART or SPI?
Any tips are greatly appreciated!