MT8870 DTMF Audio/Speech Decoding Telephone 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.

The MT8870 Tone Decoder is a kind of
commonly used multi-frequency decode IC product developed by the MITEL
company. It is a complete DTMF receiver. After it received the DTMF
signal, it will divide the signal into high-frequency group and
low-frequency group and send the signal to the digital decoder which can
figure out the key value then send it to the outside Bus via four
lines( Q1, Q2, Q3, Q4) as the binary form.

1. Onboard voice input interface
2. Low power consumption
3. Internal gain setting amplifier
4. Onboard LED, it is very convenient to check the output state.
5. Adjustable guard time
6.  Central office quality
7. Onboard 3.5mm input interface
8. 5 Channel interface
9. On-board MT8870 frequency decoder chip
10. Power-down mode
11. Inhibit mode
12. Onboard audio input interface
13. Onboard LED lights for output state indicationComplete DTMF Receiver.
14. Does not require external circuits or wiring, it can be inserted directly into the UNO/MEGA2560/DUE board to use.
15. 12-Digital outputs decode mobile and fixed telephone keys (0-9, *
    #). Also, another 4 Digital output(ABCD) can use “DTMF Dial” for
    Software control.

 Package Includes:

1 x MT8870 DTMF Audio/Speech Decoding Telephone Module