One late night many decades ago, I chanced upon a technical description of the Touch-Tone system. The book I was reading had an explanation of how each key on a telephone sends a combination of two ...

Voice over IP systems have many methods to leverage DTMF digits depending on the signaling mechanism used. All traditional time division multiplexing (TDM) interfaces on Cisco routers support passing ...

A practical look at Dual Tone Multi Frequency and RFC 2833/4733 It's easy to get lost in the technological babble of our industry. We are awash in acronyms, product names, standards (real and pseudo), ...

The project utilizes a NTE1690 DTMF dialer chip and a PIC16F690 microcontroller in order to create a dialer box that connects to the phone and can be used to dial and store phone numbers, pins, and ...

Excellent to remotely control via GSM the activation of engines, lightening or watering systems and alarm systems. It sends commands through SMS as well as with DTMF dual tones and allows you to check ...

Scienceprog has posted how-to build a DTMF tone detector. DTMF are the standard sounds used in tone dialing. Plugging this circuit into your phone line you can decode the all the tones on the line ...