@Grubstake I suspect @carwywin pretty much ticked all my particular boxes.. Comms is not really the issue even though perceived as such, a central comms link will certainly work, if you can direct link off the side of a sheet clad side of a shed so be it, or make a reflector.
It is all down to reliable acquisition of the data which informs the system. I would have to agree that the RFM69 solution would be my own personal preference, only because I settled on that as my particular solution after much chewing over options, YMMV. Wifi, here I have 6 different competing signals, on 430MHz only my car fob on a quick scan, but have no idea yet if the node will cause chaos if the local gypsies decide to camp in the car (as the remote locking is de-activated, time will tell ... It is a Citroen car, already an electrical and programming challenge as most modern cars are, my lot in life for loving hydropneumatic suspension, the last of their kind I understand...
I suggest keep an open mind on comms, the 1km range is not insurmountable, concentrate on the what, develop the how later...
