It seems there are errors in the given example programs written by analog devices. Actually, for testing purpose initially I took 'ADC0_RTD' program for measuring the temperature using RTD pt100. For example see that below, configuration states that internal reference has been selected. But actually, external reference has been configured.
ADC0CON = BIT0 + BIT2 + BIT4 + BIT10 + BIT15; // Gain = 32, Unipolar, enable ADC0, Int Reference
And, in the below statement, excitation source0 has been configured for driving 200uA current.. But the comment says, 400uA.
IEXCON = BIT1 + BIT6; // Enable Excitation Current Source 0 - 400uA
But, the real problem is If I flash this example program, the results were not correct ie, around ambient temperature, the program says that temperature of RTD is -8 degC. I don;t the where the real problem is? Also please clarify how this formuale is arrived? Why the reference voltage (internal or external) is not considered?
// Equation = ADC0Result * ((RREF/Gain)/# of bits)
Rrtd = (float)ulADC0Result * ((5600.0 /32.0) /0xFFFFFF);