Unfortunately I have limitations: Power and reliability.
The whole thing will be outside in the weather on a remote farm location 24x7. There is no power or internet connection available. I have to power it via a solar panel / charge controller / lead acid battery. I already have one Android prototype that has been running this way successfully for months (See attached). Low power is important so I don't want either the board or the phone using a Bluetooth connection.
It has to be 100% reliable. The unit will be atop a high hill, exposed to high winds and only reachable with 2 people and a tractor platform. I can't have it needing to be reset. Therefore I don't like wireless connections where something might get reset. I want a physical cable for commands.
