While many of us have banished land line telephones from our houses, there are still quite a few people who utilize POTS lines today. These analog phone systems use Dual Tone Multi Frequency (DTMF) ...

The objective of the project is to decode dual tone codes into digits which are later interpreted by microcontroller. This device is very useful for decoding Dual Tone Multi Frequency (DTMF) generated ...

Winston-Salem, NC&#8212CML Microcircuits' CMX867A, a V.22 multi-standard modem IC for telephone-based information systems, includes an enhanced DTMF decoder, thus affording a more compact design and ...