16F877 vs. 16F877A

[Melanie]

I just searched through my data sheet and I don't see anything specific to the 877A.

Huh? I thought the PIC16F877A Datasheet is ENTIRELY DEVOTED to the PIC16F877A!!!

Look at the section on Comparators (section 12), look at the Voltage Reference Module (section 13).

Datasheet=Dowloaded from Microchip
Datasheet 877A < > Datasheet 877
Datasheet < > PBP Manual

adcon1=7 is essentially the same as ADCON1 = 1110 right?

Ugh.... no.

adcon1=7 is the same as ADCON1=%00000111... note the % in the statement specified BINARY, whilst the absence of anything implies DECIMAL.

ADCON1=1110 is the same as ADCON1=%10001010110... now you might find that the ADCON1 register just doesn't have that many bits...

I am not a complete loser am I?

I don't know you well enough to validate that statement! But hey, we've all been there sometime.

[DavyJones]

Huh? I thought the PIC16F877A Datasheet is ENTIRELY DEVOTED to the PIC16F877A!!!

You are correct they look so similiar I am so used to looking at just the 16f877 same thing happened when I was ordering too.

Ugh.... no.

adcon1=7 is the same as ADCON1=%00000111... note the % in the statement specified BINARY, whilst the absence of anything implies DECIMAL.

ADCON1=1110 is the same as ADCON1=%10001010110... now you might find that the ADCON1 register just doesn't have that many bits...

Again my lack of posting correctly. I meant to say
ADCON1=%000001110
I abbreviated that I was trying to imply a decimal value of 111 my mistake I should have been more concise.

I want to use RA0 as my analog in thats not a problem with the 877A is it?

[Melanie]

Stop messing with ADCON1. If it worked for the 877 it'll work for the 'A'.

Just deal with CMCON and CVRCON.

[mister_e]

You might have some issue with winpic software. If I remember correctly, there's a slight difference in the programming between 16F877 and 16F877A.

Make sure winpic support the A version or you select it before programming your PIC, and try to do a programming check.

[DavyJones]

Stop messing with ADCON1. If it worked for the 877 it'll work for the 'A'.

Just deal with CMCON and CVRCON.

Will do I just wanted to double check myself making sure I had that set correctly which it's apparent I do.

By default it looks like according to the 16F877A (I just downloaded the correct data sheet) that CVCRON by default is off so I need'nt worry about that correct?

You might have some issue with winpic software. If I remember correctly, there's a slight difference in the programming between 16F877 and 16F877A.

Make sure winpic support the A version or you select it before programming your PIC, and try to do a programming check.

I checked to make sure both microstudio and winpic have the 877A listed and made sure they were selected when I compiled and uploaded. FYI. WinPic auto detected the 877A and set itself.

Thanks all

David