We’re going to be out of town for the weekend and a problem arose when we started thinking about how to turn on the lights for the hydroponic setup. Using a relay controlled power outlet that I whipped together for another project + a C.H.I.P., I was able to easily port over the code I was using for my Wake Up Light (check it out) for use in this system.
As far as code modifications go, I ended up removing PWM functionality since we’re dealing with a mechanical relay + fluorescent lights instead of a solid-state MOSFET + LED strip. Since the C.H.I.P. doesn’t have (at least I haven’t found any) GPIO abstraction libraries yet, manually interfacing with the GPIO’s file descriptors ended up being the route I took. When 6AM rolls around, the lights will turn on and then off at 9PM.
Here’s the link to grow_light.c on Github