Jim Hartmann wrote:
>
> I once wrote an autocorrelating DTMF decoder that worked pretty well.  It
> worked very well in the presence of noise but it worked poorly when there
> was significant twist in the signal (one of the tones higher amplitude than
> the other).  I correlated a zero crossing input against two tone references
> in real time, 8khz sample rate, taking one row and one column of the DTMF
> tones at a time, and 0 and 90 degree phase shifts of each tone.  If
> interested I can send more details.
>
> :-Jim

Jim,
I'd be interested in some more details of this.
TIA
Josh Koffman
joshy@mb.sympatico.ca