[conspire] Watering automation: an edge case cautionary tale

[Rick Moen]

Quoting Ross Bernheim (rossbernheim at gmail.com):

> While there are ‘hats’ for the Raspberry Pi that can do a/d and other i/o,
> the low price of Arduinos makes them a good choice to handle the 
> interface between the Pi and external hardware in the real world where
> you need a/d and real time control.

One of the other reasons the Arduino is frequently perfect for handling
controls on the analogue side is its extremely low power draw.  You can
literally run one autonomously as a controller in the garden on a pair
of AA alkaline batteries and have it run for, literally, years.  (This
assumes you've picked all associated parts for low power.)

https://openhomeautomation.net/arduino-battery/

I hear about people using a Raspberry Pi as the real computer that
decides how to periodically modify an Arduino's simple instruction set.
Once set, the Ardunio's instructions will persist even if the remote
'real computer' comes and goes.