I am building a system to automate a vertical farm (specifically watering, lighting, and drying) and am having trouble choosing between a wired or wireless system architecture.
The farm is arranged into a vertical matrix of 'trays' (like drawers in a large cabinet - each tray has one specific type of crop) that is currently ~7x7. Each tray must be independently controlled.
Each tray will need two relays for two solenoid valves (source and drain) and feedback from a float switch for watering, plus an additional two relays for lighting and drying control - meaning 4 digital outputs and one digital input per tray.
The entire system will be controlled form a central computer. For the current farm this would entail 196 outputs and 49 inputs, but I want to design this system such that it can be scaled to any size.
So these are my questions:
For a wired network,
-Can I chain together a (theoretically) infinite number of shift registers to give me the required number of digital outputs to control these simple devises?
-Is there something similar to a shift register that can manage a large number of digital inputs and reduce the number of pins required on the computer board?
-Between a wired architecture (using something like an Arduino/raspberry pi with shift registers) and a wireless one (using something like a Zigbee mesh network to manage all the devises), will they both have similar reliability?
Thanks in advance!