- Connect the GND pin to GND on the Arduino.
- Connect the VIN pin to the 5v pin on the Arduino.
- (For 3.3v microprocessors, connect the pin marked 3Vo to the 3.3v supply)
If you connect an external voltage reference to the AREF pin, you must set the analog reference to EXTERNAL before calling analogRead() (e.g. in your setup() function). Otherwise, you will short the internal reference with the external reference, possibly damaging your Arduino board.