Solar Tracking Display with Integrated Stepper

Solar panels can be a great way to generate extra electricity for your home, or even to supply something like a remote monitoring station where grid power isn’t available. While you could simply stick a panel in a convenient location facing roughly upwards, you’ve undoubtedly noticed that the sun doesn’t stay in the same position throughout the day. Therefore, if you can get your panel to move with the sun, this can boost power collection by 15 to 40%.

To facilitate this kind of movement, Frank Migge has come up with the SunTracker2 Revision 3 — and, of course, the previous versions needed to get to that point. The project takes the form of a rather large PCB in a beautiful see-through enclosure. Mounted to this PCB are electronics including a pair of 128 x 64 pixel OLED readouts, plus 32 bi-color LEDs. These LEDs self-align using a Sunhayato MM-TXS05 I2C magnetometer, and show the direction of north, sunrise and sunset, as well as the actual position of the sun in a greenish hue. Along with this LED indication, a stepper motor is implemented and attached to the acrylic front cover. This points to the sun position LED and could be useful for designing a motor control system for an actual sun tracking device.

The build is based on an Arduino MKR Zero, with the built-in SD card reader used to input pre-calculated sun tracking patterns. Currently, the device has two years of operational data stored, making an excellent visualization of the sun’s movement, or perhaps as the basis for a solar tracking photovoltaic (PV) array in the future.