It was a bright, sunny day, so why not build a homemade solar tracker? Solar trackers help solar panels always point at the sun as the sun moves from east to west across the sky. They slightly improve efficiency of panels connected to them.
We took an old “C-band” satellite rotator and controller, and soldered some wires up to the “east” and “west” movement buttons to give us a couple of dry contacts that we could control with electronics. We chose (2) X-10 Universal Modules which momentarily close the dry contacts when a signal for it comes down the powerline (which a computer can control). One module for east, one module for west. The contacts short for about a second and a half with every ON command. Starting at the east-most side, 18 WEST ON commands make it go to the extreme west-most side.
After verifying the modules worked properly, it was then time to start writing code! After calculating the number of possible minutes of sunlight after subtracting the Sunrise time from Sunset time, we took the result and divided by 18 to find out how many minutes between ON commands. It is this interval (45 minutes right now) that the rotator will move west. At the end of the day when the rotator is at its west limit and the sun sets, the rotator will turn all the way back to the east limit to prepare for the next day.
This was a pretty fun project to conceptualize and put in to operation in a single day. The jury is still out on whether or not the extra energy produced will offset running the rotator, especially on non-sunny days.
