internal reference voltage for 16f877

Hi

Just a simple question.

What is the default internal reference voltage for 16f877 and how do i change it?

I know that you have to put a potentiometer at RA2 and RA3 but that's all i know. How do you change the refence voltage using the pic basic pro compiler? what should i do with the ADCON1 register?

Thanks.

pt3rg said:

Hi

Just a simple question.

What is the default internal reference voltage for 16f877 and how do i change it?

I know that you have to put a potentiometer at RA2 and RA3 but that's all i know. How do you change the refence voltage using the pic basic pro compiler? what should i do with the ADCON1 register?

Thanks.

Click to expand...

The internal reference voltage is the 5V supply, if you use an external reference you may as well make it a precision one - using just a pot only makes it adjustable, not any more accurate.

All the details are in the datasheet, it tells you what each bit in the registers does - presumably the instructions for PIC BASIC will tell you how you can change them?.

Set the ADCON1 register according to the PIC's datasheet so that you can have a PIN as your reference voltages. You can set the reference voltage Vref+ and -Vref. Or just simply make the Vref+ relative to ground..... either way you adjust ADCON1 = &XXXXXXXX

Ivancho