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 ...

Decoding the telephone-generated DTMF is the purpose of building the DTMF decoder 2 which can be connected directly to a serial port and use a HyperTerminal on a PC to view the digits. A 16×2 LCD ...

Though many of us will never have experimented with it, most readers should be familiar with DTMF as the tones used by the telephone system for dialling. If your youth was not misspent mashing 4-4-2-6 ...

Sometimes you start building, and the project evolves. Layers upon layers of functionality accrue, accrete, and otherwise just pile up. Or at least we’re guessing that’s what happened with [Varun ...