hello everyone I am graduating with my associates degree from itt tech in September have been into engineering and electronics since i was about fifteenth i am in my final semester and i would like to design a electronic circuit that takes the phone tones from your basic land line phone and converts them to there Fourier transforms and then to the numbers as a homemade caller id question 1 does anybody think this will work do how would you go about implementing it suggestions are welcomed

 

That's a lot of work, unless you want to do it as a project. The tones are defined, so there are other ways to catch them - http://www.boondog.com/tutorials/dtmf/dtmf.htm

Caller ID is yet another thing from the touch tones. If enabled, there is a burst of ASCII characters between ring one and ring two that contains the caller information - http://en.wikipedia.org/wiki/Caller_ID

 

I once wrote some software to decode CallerID from a sound card in a PC, after searching the internet failed to turn up any ideas of how to demodulate the signal in hardware.

http://www.ecstaticlyrics.com/electronics/telephone/CallerID/

I still haven't been able to think of a way to do it electronically, short of using a microcontroller with an ADC, but that's software again. ...but the algorithm is rather simple, since it takes a shortcut rather than perform a real Fourier transformation, and so I imagine it is possible to implement it in a microcontroller. You can also leave out the two square root functions since the two values are just compared to each other afterwards.

 

thank you for the suggestions they were very helpful there is still so much i have to learn when i get it done will take a picture and put it on with schematics thanks again