Sunday, 30 October 2011

Mobile Operated robot(DTMF Tech.)

MOBILE OPERATED ROBOT: The robot is made for the purpose military operation, spy robot or navigator in forest.The mobile operated robot is a very small application of DTMF technology we showing you how we can use the DTMF to operate a robot  because the robot is operated by a mobile so the range of the robot communication is not limited its just depends on the network of the mobile and in present senario the mobile network is everywhere.
DTMF: DTMF(Dual Tone Multi-Frequency) , better known as touch-tone is a system of signal tones in telecommunications.This technology is used in several of Applications for example voice mail, customer care,telephone banking etc.
There are twelve DTMF signals, each of which is made up of two tones from the following selection.
ROW'S- 697 Hz ,770 Hz ,852 Hz, 941 Hz.
COLUMN'S- 1209 Hz, 1336 Hz, 1447 Hz , 1633 Hz.
The tones are divided into two groups (low and high) , and each DTMF signal uses one of tone from each group. This prevents any harmonics from being misinterpreted as part of the signal.

DTMF Decoder: The DTMF tone is decoded by the DTMF Decoder ic that is HT9170 which decoded a dtmf tone and gives a four bit data at the output of the decoder.Now this four bit data can be use  for  making the decision as for the key pressed on the mobile keypad the data have different for a different key.some important pin of HT9170 are listed below:-
1. Pin 15(DV data valid): The data valid pin is become high when the dtmf decoder receive a valid data or this pin hold's the 5v when the key is pressed.
2. Pin 10(OE output enable): This pin is use to enable the output when this pin is high the data pin are active and the decoded output is sent to the decoded pin.
3. Pin 11-14(D0-D3 data pins): These are the data pins which makes the 4 bit data after pressing a key on the mobile such as 0001 for pressing the key 1 and other are shown into the picture shown.
4. Pin X1 or X2: These pin's are use for providing the oscillation to the ic basically a xtal of 3.579 MHz is used here. for more details download the HT9170 datasheet .DOWNLOAD 

SOFTWARE:  For the program of this circuit click here 

CIRCUIT: The circuit is made in different modules

1.Power supply : For power supply just click here 

2.Input or DTMF decoder:
DTMF Application circuit

3.Decision (microcontroller 8051): For 8051 microcontroller circuit just click here  

4. Motor driver circuit:  The IC-l293d  is well known as motor driver this is 12v motor driver we use the motor driver IC because our micro-controller is work on 5v and the motor have different operating voltage. So to meet with these parameter we use these driver IC there are so many other IC available for different configuration.

The full circuit for mobile operated robot is as follow :

back & front view of circuit

final robot

About the Author


Author & Editor

Hobbyst Researcher and working in electronics domain, M.Tech in VLSI Design and Embedded Systems.


  1. for any other information mail me at

    1. Sir Can you tell me how exactly have you connected the ear phone to the dtmf decoder input ?

    2. hi sharada prasad u just cut the headphone at its speaker then u will get two different color wire

      now separate them and burn them to clear its coating and put a small female connector with these two wire and one terminal with ground and secod with the tone terminal

    3. Sir is it possible to construct a Robot Vehicle without using Microcontroller? if yes, then may you plz tell me about the required circuit diagram,,,,

  2. really great work..
    1)short, simple and superb theory!
    2)clear and self explanatory ckt diagrams.
    3)necessary links are provided for required datasheets.
    4)even a starter without having much knowledge of robotics can make his project.
    but yeah...
    there is one thing missing..list of all components used with quantities
    rating: 9.5/10
    hatts off...:)

    1. thanx akhil hope we will give the list of components in our next blogs....and thanx again...

  3. DHANSHU IDEA.................

    1. hmmm can used at anti terrorism activities....

  4. sir suggest me an easy project that would use dtmf concept but no programming ic's

  5. sir,could you please tell me how to connect ear phone to the dtmf decoder input/What is A Jack and what does it do?

  6. Thanks your blog is awesome.
    thanks for sharing information.

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  7. sir i want to know how many voltage is given by the 9170 ic at output pins.

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