why is the internal votage reference used in AN-0970 source code? The AN says, that the ADC result is independent of excitation current changes, because the ratio of Vin/Vref ist measured. But in source code the internal reference is used:
ADC0CON = BIT0 + BIT2 + BIT4 // Gain = 32, Unipolar, enable ADC0, Int Reference (clear BIT0 for Gain = 16)
+ BIT10 + BIT15;
Is there any reason?