PCA9685 - Multiple Servo Control Using Arduino

The PCA9685 - Multiple Servo Control Using Arduino project relies on offloading pulse-width modulation (PWM) generation from an Arduino Uno R3 to a dedicated PCA9685 16-Channel PWM Servo Driver Module. An Arduino Uno R3 has a limited number of hardware PWM pins, which makes driving eight or more servo motors simultaneously challenging without running out of timer resources or processing power. The PCA9685 module solves this bottleneck by communicating with the Arduino over the I2C protocol, requiring only two data lines (SDA and SCL) to control up to 16 independent PWM channels. Powered by an external 5V power adapter to safely handle the high current draw of the motors, the driver features an onboard clock that continuously generates the necessary PWM signals to hold the SG90 servo motor positions steady. The Arduino IDE, utilizing the Adafruit PWM Servo Driver Library, sends simple I2C commands containing target channel and pulse-width data to the PCA9685. The driver translates these commands into precise duty cycle signals that dictate the exact angular position of each of the eight SG90 servos. Common ground must be established between the external power supply, the PCA9685, and the Arduino Uno R3 to ensure a stable reference voltage for the I2C logic signals.