Today i completed the DTMF decoding circuit and interface it to the micro controller and DTMF tone was generated by the PC and fed to the decoder. After all the connections i wrote a test code for micro controller to get the decoded signal. With an interrupt i manage to get the decoded values from the tone generated.
To view what i am getting i connected the LCD and found some problems and after a while i menage to fix it. from the flow you can see how it works. Then i have to test this from a mobile phone and for that i need to make a small preamplifier to control the volume.