Analog-to-Digital Converter Interrupt

The Analog-to-Digital Converter is the hardware feature of the ATmega328P which gives you the ability to execute Arduino code which calls the analogRead() function. It has a single interrupt which informs you when it has completed a conversion of the voltage on its input pin into a value your code can use. As far as the Arduino is concerned, that’s it; however, there’s more to the Analog-to-Digital Converter than the Arduino lets you know about.