Connections: Auxiliary board: Input power: Green connector Pin 1 (top) +5V Pin 4 (bottom) GND Pin header (top to bottom): +5V to RPi pin 4 (+5V) (unused) (unused) GND to RPi pin 6 (GND) PWM input from RPi pin 11 (GPIO17) Servo PWM output Servo +5V output servo GND output SRF02 range finder pin header (right to left): +5V from RPi pin 2 (+5V) SDA from RPi pin 3 (GPIO2/SDA) SCL from RPi pin 5 (GPIO3/SCL) (unused) GND from RPi pin 25 (GND) RPi header 5: Pin 6 (GPIO31) to halt button Pin 8 (GND) to halt button