I am relatively new to the Raspberry PI and have not used Cayenne before, however:
I am working on building an irrigation controller. So far I have built it up using an inherited raspberry PI 2B and a Denkovi 8 channel USB relay board. Denkovi supply their own GUI control software which works on Raspian. I have had all this working quite nicely.
However I have recently stumbled upon Cayenne and it is a no-brainer to try set it up for the ultimate remote control. As of yet, I haven’t found any guidelines on how I should go about controlling the USB board through the Raspberry PI, as this of course does not use the GPIO pins (in hindsight would have been a cleaner solution with using Cayenne). Is anyone able to give me some pointers on where to start?
As an aside, there is also command line software which can run basic control of the relays. As one method I assume Cayanne can execute command line script on the RPI?