I have a couple a Raspberry Pi with some I/O modules that I am controlling directly using Viking. In order the interact with Viking I am mocking the Denkovi web protocol, so basically the RPis present themselves as Denkovi DAEnetIP4 board.
It works perfectly, however not all the IO ports are available in the RPi and there are some RPI boards with far more ports than the Denkovi, so I like to request a generic protocol for controlling HTTP based IO cards.
For instance, Viking would retrieve the IO port definition at initialization, getting the data from:
This file will contain number and description of the IO ports
Then for IO control we can pass the control parameters and retrieve the board status in one call (similar to denkovi protocol):
With this open protocol, it would be easy to properly support any IO card hooked to an RPi or similar board.
If you decide you move forward with this idea I will write and make open source a couple of webservers in python to fully control a PiFace IO module and Velleman P8055 IO board from an RPI.
If anyone is interested in connecting their RPI with Viking using the Denkovi protocol feel free to contact me.