RE: CRC problem

Hi Donald,

 

I've also run this through a number of CRC16 routines with various
polynomials and nothing matches the CRC on the end.

 

What does the manual for the telemetry say about it? In particular, which
bytes of the telemetry are included in the CRC calculation. 

 

I am working on a device just now where the first 8 bytes are a header and
not included in the CRC so wondering if yours is similar?

 

Does the telemetry manual give you the polynomial used?

 

Dave.

 

From: [email protected] [mailto:[email protected]] On
Behalf Of DonaldShimoda
Sent: 18 March 2013 01:50
To: [email protected]
Subject: [rabbit-semi] CRC problem

 

  

Hi, 
Im trying to get a CRC16 routine but cannto find the rigth way to get it.
I have two samples of bytes comming from a device, Manual say if you apply
crc16 to all that bytes you must get 0 as result, but dont work.

That are the chains:

50 30 02 08 00 00 02 44 00 00 38 86 03 04 00 00 00 00 01 01 00 d5 f8

51 30 02 08 00 00 02 07 00 00 84 81 03 04 00 00 00 00 01 01 00 4b ed

last two are the hex crc values.

As im reading this from a device, i make a loop and try 3 crc routines
working on other situations, and changes the inital value to 0x0000 and
0xFFFF in every test, and increment base from 0x0000 to 0xFFFF but in that
situation dont work. I cant fond a crc routine/base/initial combination
returning zero for both chains...

I even try the getcrc rabbit lib routine, no look.

Also try this site, severlas crc routines calcule, dont work either

http://www.lammertbies.nl/comm/info/crc-calculation.html

Can somebody give me some clue on this?

Best regards.