ADC FVR (Fixed Voltage Reference)

[Jan Lichtenbelt]

I want to use the ADC Fixed Voltage Reference FVR in case of the 16F18857 microchip.
http://www.microchip.com/wwwproducts/De ... /documents
I choose a potentiometer as example for input of an ADC. There is a possibility to choose "FVR" as Vref option in the ADC macro.
But this chip has three possible FVRs: 1.024 V, 2.048 V or 4.096V. The ADC macro does not show which FVR will be choosen.
What to do?

Kind regards

Jan

[Jan Lichtenbelt]

In the meanwhile I found a solution by entering the c-code after the RawEnable macro:

//ADC Vref+=FVR=2.048 Volt
FVRCON= FVRCON | 0x82; // set bit 1 (FVR 2.048 V) and 7 (FVR enable)
FVRCON= FVRCON & 0xFE; // clear bit 0 (FVR 2.048 V)

This gives ADC values between 0-1024 for voltages between 0-2.48 Volt.

Kind regards

Jan