I have a pic16f677 with a fixed internal vref of 0.6v. I figured out how to use vdd as the input for the adc but I want to use the internal volt reference. I've done some reading and I think you have to change ADCON0 to some value? Btw the data sheet for the chip is **broken link removed** and I program in mikrobasic. Any help is very much appreciated.
The adjustable 0.6 Volt nominal internal reference is primarily used by the on board comparators. It's value can be read by the A/D, but not used as a reference for an A/D conversion. If you need more accurate A/D conversions, feed an external ref voltage to the A/D Vref pin.