MT8870 DTMF Voice and Telephone Decoder Module

This component is ideally suited to adding dual tone multi frequency (DTMF) decoding to your project. This detection module interprets the incoming tone and produces a coded output that can be connected to all manner of microcontrollers.

DTMF is commonly found in touch tone devices such as a phone. The tone is a combination of two separate sine waves that produce a unique signal that can be transmitted or heard. When the module receives the signal it is able to decode it and produce a binary output that can be used in other devices. The module shows the state of the signal through onboard LEDs.

As an idea you can connect up a mobile phone via 3.5mm to 3.5mm cable to the module. Dialling into the phone from a second mobile and then using the keypad will produce the tones on the original phone. The tones in the call can then be interpreted by the module, allowing you to control all manner of projects.

The pins are suited to standard sockets with a pin pitch of 2.54mm.

Features:

• MT8870 module decodes DTMF signals from an audio source and it is suitable for remote monitoring applications, telephone answering machines and more
• A low power device DTMF decoder chip. It is a complete DTMF receiver integrating both the band-split filter and digital decoding functions
• On-board MT8870 frequency decoder chip
• On-board audio input interface
• On-board LED lights for output status indicator