Hello Muddy,

Your frequency can easily be calculated by using Pulsin in a subroutine...This has not been tested, but the idea is there. I wrote one a long time ago for RPM on a 2 stroke airplane engine.

routine:
Pulsin Pin1, 1 ,Pos 'measures the positive Pulse
Pulsin Pin1, 0, Neg 'measures the negative Pulse.
Wavelength/cycle=Pos + neg 'Adds them together for the full length
Frequency=1000/Wavelength '(in ms)
Frequency=1000000/Wavelength '(in us)
return Frequency

DTMF is a frequency...Thus the above routine can measure the frequence of the DTMF and tell you which number you pressed...

Dwayne