Using MT8870 DTMF Decoder With Arduino

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DTMF DECODERS Are used to detect DTMF TONES Genrated by mobile phone DTMF Keypad.
In this project we are going to decode the DTMF Tones into 4bit Output and this output is given to the arduino which detects the keypress and displays it on LCD

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Step 1: Components Used

The components that I have used are easily available locally in most of the cities or you can also buy it online

Step 2: Circuit Diagram

Use the above Circuit Diagram and build the circuit.You can change it according to your need

Step 3: Giving DTMF Input to Circuit

The input is given by a mobile phone with a 3.5mm jack which provides the DTMF signals to MT8870 decoder

Step 4: Programming the Arduino

I used USBasp to program arduino u directly program it using usb it is better to use usbasp if you are building the circuit on breadboard

Step 5: Arduino Code

Use the code to program arduino
it uses hex codes for numbers pressed on dialpad of mobile

The Hex Codes For Keypress Are As Follows
1 = 0x01
2 = 0x02
3 = 0x03
4 = 0x04
5 = 0x05
6 = 0x06
7 = 0x07
8 = 0x08
9 = 0x09
0 = 0x0A
# = 0x0C

Step 6: Getting Output on LCD

The decoded key shown on a LCD Module In this picture the # key is pressed on mobile phone and it is also shown on LCD Module

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    12 Discussions

    None
    tanu shradhali

    Question 1 year ago on Introduction

    if we wanna to interface to dtmf and arduino .so will be the requremeny libraries

    None
    ovidiu_seran

    2 years ago

    Hello,

    Very nice project. But I would like to ask if it is possible to add a sequence at startup, where you should "login" first then give commands to the arduino.

    This way will be safer in use this project!

    Thanks a lot.

    None
    GuidoSan

    2 years ago

    My bad - theres a perfect image in the zipped files I just wasn't smart enough to look.

    None
    GuidoSan

    2 years ago

    Is it possible to get a clearer image of the circuit layout. I can't quite read it but i really want to build it.

    Thanks

    None
    vedprakashv

    4 years ago on Introduction

    hello sir plz tell me what type arduino use and what the process to burn the program in it.

    None
    CircuitToday

    4 years ago

    it available in Arduino IDE to Compile .

    None
    CircuitToday

    4 years ago

    Pin is function for Atmel microcontroller which reads the state of a specific pin

    C Means The PortC Of Microcontroller
    its the analog input port of Arduino the function pin reads the state of portC or Analog port

    None
    rsrini7

    4 years ago on Introduction

    Can u pls guide me what is PINC and the program is compiling with this. In Which module the PINC variable available ?

    None
    CircuitToday

    4 years ago

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