Solar Powered - BitKnitting/should_I_water GitHub Wiki
I wanted the Sun to power the moisture puck. The main reason is I am lazy. This way, I don't have to keep going to the moisture puck, remove the LiPo battery, recharge, and put back.
Thanks to Adafruit, powering the moisture puck with the Sun is simple. To do this, I used Adafruit's "plug-n-play" stuff:
As usual, Adafruit has excellent learning guides.