user19193: I am reading a 50Hz AC voltage using the analogue inputs.
If I set the analogReference() to INTERNAL, meaning 1.1V on the Arduino Uno, what will happen if a voltage greater than 1.1V is supplied to the pin? Will the board be damaged? If not, what value will the ADC give?

user4143: You will read 1023.
The limit of the voltage is not the reference voltage but the chip supply voltage - so 5v on a 5v board.

19193: <p>I am reading a 50Hz AC voltage using the analogue inputs.</p>

<p>If I set the analogReference() to INTERNAL, meaning 1.1V on the Arduino Uno, what will happen if a voltage greater than 1.1V is supplied to the pin? Will the board be damaged? If not, what value will the ADC give?</p>
 4143: <p>You will read 1023.</p>

<p>The limit of the voltage is not the reference voltage but the chip supply voltage - so 5v on a 5v board.</p>
