Well, if anyone else is interested, I have found the most useful decoding routines
yet..
http://www.microchip.com/download/appnote/keeloq/91045a.pdf
It's the "KEELOQ MAnchester Encoding Routines" TB045 document.
Still searching for others....

Les

> -----Original Message-----
> From: James Newton. Admin 3 [mailto:jamesnewton@piclist.com]
> Sent: 20 February 2002 01:55
> To: LesOtter@saurel.demon.co.uk
> Subject: RE: [PIC]:Manchester encoding/decoding routine examples please
>
>
> Oops! Good point. There is some discussion in the archive at
> http://www.piclist.com/techref/postbot.asp?by=time&id=piclist/1998/03/06/183
> 030a
> and
> http://www.piclist.com/techref/postbot.asp?by=time&id=piclist/2001/01/02/164
> 503a
>
> But no code. I looked at rocketaware.com and the US Patent office and
> without much success... you might look through the results for Manchester
> and decode and preamble at the patent office:
> http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetah
> tml%2Fsearch-adv.htm&r=0&p=1&f=S&l=50&Query=manchester+and+decode+and+preamb
> le&d=ft00
>
> Please consider sharing what you find.
>
> ---
> James Newton, webmaster piclist.com (former Admin #3)
> mailto:jamesnewton@piclist.com
> 1-619-652-0593 VM 1-208-279-8767 FAX
> PIC/PICList FAQ: http://www.piclist.com or .org
>
>
>
> -----Original Message-----
> From: Les Otter [mailto:LesOtter@saurel.demon.co.uk]
> Sent: Tuesday, February 19, 2002 15:55
> To: jamesnewton@piclist.com
> Subject: RE: [PIC]:Manchester encoding/decoding routine examples please
> Importance: Low
>
>
> James
> Thanks for that, but that's just a code snippet for encoding..not a codec.
> I am now up to speed on what bit translation goes on at each end, but the
> ancoding and decoding of a packet is what I am interested in.
>
> I am still trying to figure out how best to process a preamble header stream
> to sync the bit time to (thereby catering for various bps rates), and adjust
> the sample timer as reception proceeds to account for frequency drift.
>
> I would like to send, say a 32 bit preamble (16 1-0 or 0-1 pairs), followed
> by a header block of say 4 bytes (of 0-0 pairs) - which would signify the
> start of actual data.
>
> Then receive (in Manchester format of course!) two bytes which signifiy the
> length of data packet.  Then process the bitstream, adjusting the clock as
> we go.
>
> I think the KEELOQ encoders send a similar pattern, but without the variable
> data packet bytes.
>
> Rgds
> Les
>
> > -----Original Message-----
> > From: pic microcontroller discussion list
> > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of James Newton. Admin 3
> > Sent: 19 February 2002 23:12
> > To: PICLIST@MITVMA.MIT.EDU
> > Subject: Re: [PIC]:Manchester encoding/decoding routine examples please
> >
> >
> > source= http://www.piclist.com/postbot.asp?id=piclist\2002\02\19\071218a
> >
> > Manchester codec for PIC's in the FAQ at
> > http://www.piclist.com/techref/microchip/manchester.htm
> >
> > ---
> > James Newton: PICList.com webmaster, former Admin #3
> > mailto:jamesnewton@piclist.com  1-619-652-0593 phone
> > http://www.piclist.com/member/JMN-EFP-786
> > PIC/PICList FAQ: http://www.piclist.com
> >
> > --
> > http://www.piclist.com#nomail Going offline? Don't AutoReply us!
> > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body
> >
> >
>
>

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu