If you want to use the '''ARef''' for a voltage reference under 3.3v, the line code to use is {{fname|analogReference(AR_EXTERNAL)}} with '''AR_EXTERNAL''' and not ''EXTERNAL''. | If you want to use the '''ARef''' for a voltage reference under 3.3v, the line code to use is {{fname|analogReference(AR_EXTERNAL)}} with '''AR_EXTERNAL''' and not ''EXTERNAL''. |