The Arduino has several power pins. They are as follows:
- VIN: This pin is used when we power the Arduino board using an external power supply. This is the pin used in the Using the VIN/GND pins to power the Arduino section of this chapter.
- GND: These are the ground pins.
- 5V: This is 5V out and is used to power most sensors.
- 3.3V: This is 3.3V out and can be used to power sensors that are compatible with 3.3V. A list of some compatible 3.3V sensors can be found here: https://www.dfrobot.com/wiki/index.php/3.3V_Compatible_Device_List.
- Reset: This pin can be used to reset the Arduino board by an external source.
- ioref: This is the reference voltage for the board. For the Arduino, this will be 5V.