MT8870 DTMF Decoder Module Features
DTMF stands for Dual-tone-multi-frequency. This module is for sending signals using the voice-frequency band over telephone lines to switching centers. This module has two important applications: First, to specify the desired number to telecommunication through switching centers; second, it is capable of transmitting commands to these centers and other telecommunication devices.
- Input voltage: 5V
- 5mm input jack
- LED to indicate the binary outputs status
- Recognize numbers 0-9, letters A-D and symbols *, #
MT8870 DTMF Decoder Module Pinout
This module has 6 pins:
- VCC: Module power supply
- GND: Ground
- Q[1-4]: Binary Output
- EST: Early Steering (Output)
- INH: Inhibit (Input)
- TOE: Three State Output Enable (Input)
You can see the pinout of this module here.
Different modes in each pin represent different data. The following table shows different modes:
You need an AUX cable to interface this module.
Interfacing MT8870 DTMF Decoder Module with Arduino
Step 1: Circuit
The following circuit shows how you should connect MT8870 module to Arduino and to the mobile phone using the AUX cable. Connect wires accordingly.
Step 2: Code
Upload the following code to your Arduino.
/* MT8870-DTMF-Receiver-Module Made on 09 Feb, 2021
In this program, you can evaluate the performance of this module using the mobile keyboard. By touching each number 0 to 9 and also the # and * symbols, you can see them in the Serial Monitor.
The output is as follows: