Analog input channel properties

Analog input reference voltage

Set the reference voltage used to measure inputs to the ANALOG IN pins.

This parameter appears when the Target hardware parameter is set to Arduino Mega 2560 or Arduino Uno.

Warning

Only connect an external power source to AREF while this parameter is set to External. Connecting an external power source to AREF while this parameter is set to any other option exposes the internal voltage references to the external voltage. This voltage difference can damage your hardware.

Do not connect Arduino^® Uno and Arduino Mega 2560 to voltages greater than 5 Volts.

Do not connect Arduino Due to voltages greater than 3.3 Volts.

Voltages greater than the specified limits can damage your Arduino hardware.

Settings

Default: Default

Default

Use the default operating voltage of the board. For Arduino Uno and Arduino Mega 2560 the operating voltage is 5 Volts.

Internal (1.1 V)

Valid for Arduino Mega 2560 only: Use the internal 1.1 Volt reference.

Internal (2.56 V)

Valid for Arduino Mega 2560 only: Use the internal 2.56 Volt reference.

External

On the Arduino Uno, Arduino Nano and Arduino Mega 2560, use an external 0-5 volt power supply connected to the AREF pin. This voltage should match the voltage of the power supply connected to the Arduino hardware. If your application requires low-noise measurements, use this option with a filtered power supply.