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 ...

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 ...

The last blog entry covered DTMF relay. This blog entry will focus on Cisco IP Phone and Cisco SIP Trunk DTMF relay support. Cisco’s first generation of IP phones do not support RFC2833 DTMF-Relay.

DTMF digits are also used to specialized functions like voice mail login, automated attendant (AA), and interactive voice response (IVR) systems. DTMF digits are frequency combinations that enable ...