Problems with CRC8 Calc in 1Wire

[JohnB]

Tried that - this is the result:

A8
13
06
46
A4
65
76
E5
CRC Error E5


JohnB

[Tom Estes]

You are jumping around the subroutine upon start up right? If your software is verbatum to what you posted then you need to add Goto Start just before the CRC8: label and place a Start: label before your testcode comment. I'm not sure what PBP will do with variables declared after coding starts but I would move the TestData VAR Byte(8) up to before the subroutine where the other declarations are.

Again, I'm away from home for a couple of days so I can't test the code.....

[JohnB]

Can't believe how stupid I have been, indeed it was an extract from a much larger program which I was having a problem with. In the extract I was skipping over loading the array so it was never getting to operate on correct data.

I will now have to go back to my original code and see where it is going wrong as I still have a problem with the real code, it just not with the CRC calc as I h ad originally thought.

Sorry to have bothered you.

JohnB

[BigWumpus]

Yesterday I have implemented the CRC-8-calculating from 1-wire with a short routine without tables from:

http://www.dattalo.com/technical/software/pic/crc.php