Build an Arduino Dual Axis Solar Tracker System

The Arduino Dual Axis Solar Tracker System operates on a closed-loop feedback mechanism designed to keep a solar panel directly perpendicular to incoming sunlight throughout the day. At the heart of the system are four 5mm Light Dependent Resistors (LDRs) mounted strategically around the solar panel. Each LDR acts as a variable resistor whose electrical resistance decreases as the intensity of light striking its surface increases. These sensors are wired into the Arduino Uno's analog input pins along with four 10k ohm resistors, forming potential divider circuits that convert varying light levels into readable voltage signals. As the sun moves across the sky, the amount of light hitting each LDR changes unevenly, creating a voltage differential between the sensor pairs. The Arduino Uno reads these analog values and continuously compares the light readings from the opposing pairs. Based on these comparisons, the microcontroller generates precise Pulse Width Modulation (PWM) control signals to drive two micro-servo motors. One servo handles the horizontal (azimuth) movement, while the second servo controls the vertical (elevation) tilt. By incrementally adjusting the physical orientation of the 3D printed mechanical assembly holding the solar panel, the system minimizes the light difference across all four sensors, thereby locking the solar panel onto the point of maximum illumination and optimizing daily energy harvesting efficiency.