Yes, that was my original response, to use a VD, but I wasn't aware you could put above 5v to the pin, to measure 12v you need a VD, as it will only ever see a max of 5v due to it's internal Voltage Ref, however, question, if I was to use a PIC18F for ex which supports an external voltage reference, could I put 12v into VREF and measure the ADC via the external Voltage Reference instead of having to use a VD does anybody know (putting a limiting resistor in series).