The goal of this project is to build a solar tracking system to charge an 18650 battery. Four light sensors, one for each of the corners of the solar panel mounting board, allow the system to track the strongest light source. Two servo motors installed in pan-and-tilt brackets allow the system to rotate the solar panel board perpendicular to the light source. The light sensors are breakout boards, each housing photoresistors that determine the intensity of incoming light. By using the light sensors and the servo motors to rotate the panels, the idea is that we can charge the battery as fast as possible. The STM32L476RG Nucleo board is responsible for monitoring the light intensity values, as well as controlling the angles of each servo with the appropriate PWM signal.

There is also a battery percentage display on the outside of the enclosure, as well as a USB charging port. The USB port is connected to the solar panel and battery. Without a battery, it will charge the device using only the panels. With a battery installed, it charges using the 18650 as a power source. In either case, the solar panels will continue to charge the battery.