Searching \ for 'DTMF tone detection with PIC' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/pots/dtmf.htm?key=dtmf
Search entire site for: 'DTMF tone detection with PIC'.

Truncated match.
PICList Thread
'DTMF tone detection with PIC'
1995\11\09@152329 by Scott Stephens

picon face
I was wondering if anyone has used a PIC to detect dtmf. A method that comes
to mind would be to generate all the individual tones with timers based on
the RTCC/TMR0, and then compare the unknown DTMF squarewave input using an
XOR instruction to the individual tones. Any other idea's or methods?

1995\11\09@163149 by Warren Crossfield

flavicon
face
There is a new xceiver called "CM8880 DTMF" that may fit your needs. Not sure
who makes it, but I bought one from Scott Edwards along with some insights for
it's use.

Scott Edwards
520-459-4802
_______________________________________________________________________________
Subject: DTMF tone detection with PIC
From:    stephnss%spam_OUTPYROTECHNICS.COMTakeThisOuTspamprdnet.polaroid.com at INET
Date:    11/9/95  4:23 PM

I was wondering if anyone has used a PIC to detect dtmf. A method that comes
to mind would be to generate all the individual tones with timers based on
the RTCC/TMR0, and then compare the unknown DTMF squarewave input using an
XOR instruction to the individual tones. Any other idea's or methods?

1995\11\10@194419 by Paul Christenson [N3EOP]

flavicon
face
>I was wondering if anyone has used a PIC to detect dtmf. A method that comes
>to mind would be to generate all the individual tones with timers based on
>the RTCC/TMR0, and then compare the unknown DTMF squarewave input using an
>XOR instruction to the individual tones. Any other idea's or methods?

Your XOR method may work on paper; even in the simulator, but there are far
too many variables to get it to work with any real reliability.

There are two workable ways to solve your problem; either with a DTMF
decoder chip, or use a PIC with A/D converter and use a Fast Fourier Transform
(details are available in most college communications texts.

More... (looser matching)
- Last day of these posts
- In 1995 , 1996 only
- Today
- New search...