Comparator

[YAN-1]

Hi. I was trying to choose between the 16F877 and the 16F877A. I just don't understand the comparator additional feature in the 16F877A. Doesn't the 16F877 have a CCP module (that includes a comparator). thanks

 

[Jay.slovak]

Hi. I was trying to choose between the 16F877 and the 16F877A. I just don't understand the comparator additional feature in the 16F877A. Doesn't the 16F877 have a CCP module (that includes a comparator). thanks

This is A's Additional function (Analog Comparator - mostly it's not used). If you are designing new project, head to A version!

 

[YAN-1]

I'm sorry but I'm not sure I get this. If I want to compare 2 analog voltages, can't I use the CCP module in the 16F877?

 

[Jay.slovak]

I'm sorry but I'm not sure I get this. If I want to compare 2 analog voltages, can't I use the CCP module in the 16F877?

NO! CCP is Working with Digital Values!

 

[YAN-1]

Oh I see . I feel stupid!
But if I use the comparator module of the 16F877A, can I still use the A/D module in the same PIC? I am asking because they both seem to use RA2 and RA3 as their references. Thanks.

 

[Jay.slovak]

Oh I see . I feel stupid!
But if I use the comparator module of the 16F877A, can I still use the A/D module in the same PIC? I am asking because they both seem to use RA2 and RA3 as their references. Thanks.

You can use both A/D and Comparators at once. A/D will give you Absolute value and Comparator will just signalise which one is greater...