>-----Original Message-----
>From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] 
>Sent: 08 April 2005 00:10
>To: 'Microcontroller discussion list - Public.'
>Subject: RE: [PIC] Hamming ECC again... In C, this time
>
>
>> Correct, James.  With my simple Hamming code, it's impossible
>> to differentiate between a correctable one-bit error and a 
>> non- correctable two-bit error (or, for that matter, between 
>> zero errors and three errors).  
>
>Still and all, when bit 7 is set, you know there was an error 
>and the data may, or may not be corrected. A single bit error 
>will always be detected (and corrected) and the percentage 
>chance that a multibit error could get through undetected is 
>next to nothing.
>
>A very nice thing to have.

Agreed.  I suppose the addition of a checksum at the end of a data
packet would allow you to essentialy ignore bit 7.  If any single bit
errors have been corrected, the checksum will match.  A little more
overhead, but with Scott et al's equally cunning CRC functions it won't
be a great deal.

I'm planning on having a play with some of the cheap wireless modules
sometime soon, this sounds perfect for a simple error correction scheme.

Regards

Mike

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