Today, most telephone equipment use a DTMF receiver IC. One common DTMF receiver IC is the Motorola MT8870 that is widely used in electronic communications circuits. The MT8870 is an 18-pin IC. It is ...
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 ...