PCB Wiring Connections Laptop USB -> Arduino USB Arduino +5V -> PCA9685 VCC/VDD Arduino GND -> PCA9685 GND/VSS Arduino SDA (pin A4) -> PCA9685 SDA Arduino SCL (pin A5) -> PCA9685 SCL PSU +5V -> PCA9685 V+ PSU GND -> PCA9685 GND SERVO1..6 PWM -> PCA9685 CH1..6 PWM SERVO1..6 5V -> PCA9685 CH1..6 5V SERVO1..6 GND -> PCA9685 CH1..6 GND Important Notes Arduino does NOT power the servos. Servos are powered directly from PSU. All grounds must be connected together. PCA9685 generates hardware PWM signals.