DTMF- is my signal processing method possible?

Hi everyone! This is my first post so sorry if request something that I shouldn't. As an overview, I am working on a project that is collecting data from a wire which has a phone number passing along the cable. The arduino is currently reading the data and outputting to the serial monitor. Both the arduino and Matlab are communication with eachother over usb and would like to do the following to the data in matlab.

 I would like to write something in matlab that takes the fourier transform (so the data is in frequency domain)and cause matlab to start collecting data only when the frequency is above 697 Hz. I want it to then stop when it goes below 697 Hz and repeat the process. Ideally, i would like the two values (that are higher than 697hz) to be stored briefly in matlab and then sent to arduino and would like that process to continue. I say 2 frequencies as they would correspond to the row and column frequency values for the button press. Does this sound possible to do with matlab? I will admit that I have never used matlab for a project so any help will be fantastic!

Answer 1

[Wayne King]

Hi, There is an entire DTMF demo in the Signal Processing Toolbox.

http://www.mathworks.com/products/signal/demos.html?file=/products/demos/shipping/signal/dtmfdemo.html