Arduino has the ability to measure voltage using analog input pin. For Arduino UNO, there are 6 analog input pins (A0-A5) where you can use one of the pins to measure AC voltage. Arduino NANO has 8 pins while Arduino MEGA has 16 input pins. The analog input pins will map input voltages between 0 and 5V into integer values between 0 and 1023 with resolution of 4.9mV per unit (5.00V / 1023 units). Do not reverse the voltage polarity which may damage the pins.
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