Phone Dial Detector

A simple project that attempts to decode button presses from frequencies in a DTMF phone dial.

Method

• DTMF tones inputted as wav file
• Locations containing tones are found
• DTMF tone is known to be two sine waves of different frequencies added together
  • Inner product between a candidate function and the tone is found taking the largest magnitude
• Symbols are matched

Acknowledgements

Test tones generated from here