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Objective:

The main objective of our project is to develop a robot which can be

controlled via a cell phone even if we are at a very distant place from

that robot. Normally the robots come with a very limited range of

control; but this model completely eradicates this factor of limited range

as we bring in the technology of DTMF.

Requirements:

Generally our model will comprise of the following specifications:

1.A robot(consisting of motors and other mechanical specifications)2.Motor drivers3.A DTMF decoder4.ATMEGA16 microcontroller5.2 cell phones(one attached to robot and other for calling6.Motor drivers

Phases:

The model is divided mainly in 2 phases:

1.Robot construction2. Interfacing the ICs(DTMF decoder, microcontroller and motor

driver) on the robot.

3.Burning the code on microcontroller.These phases are discussed below:

1.Robot construction:A mechanical model of the robot is made by using the following:

4 wheels

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A 6V battery 4 geared motors of 6V each

2.Interfacing of ICs on the robot:

The following components are used in the circuit:

MT8870 DTMF DECODER - 1 ATMEGA 16 microcontroller1 L293d motor driver IC1 Cd7004 not gate IC - 1

1n4007 diode - 1 100 k resistances - 2 10 k resistances - 5 330 k resistances - 1 0.47mf capacitors - 1 0.1mf capacitors - 1 22pf capacitors - 4 3.57mhz crystal - 1 12mhz crystal - 1 Push to on switch1 A handsfree

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Working:

Once the above 2 phases have been completed, the model looks

like this:

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In this project the robot is controlled by a mobile phone that makescall to the mobile phone attached to the robot. In the course of the

call, if any button is pressed, control corresponding to the button

pressed is heard at the other end of the call. This tone is called dual

tone multi frequency tome (DTMF). Robot receives this DTMF

tone with the help of phone stacked in the robot. The received tone

is processed by the atmega16 microcontroller with the help of

DTMF decoder MT8870. The decoder decodes the DTMF tone into its equivalent binary digit and this binary number is sent to the

microcontroller, the microcontroller is preprogrammed(in C) to

take a decision for any given input and outputs its decision to

motor drivers in order to drive the motors for forward or backward

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motion or a turn. The mobile that makes a call to the mobile phone

stacked in the robot acts as a remote.

Advantages:

This model is a complete renovation of a wireless robot.

Conventionally, Wireless-controlled robots use RF circuits, which

have the drawbacks of limited working range, limited frequency

range and the limited control. Use of a mobile phone for robotic

control can overcome these limitations. It provides the advantage

of robust control, working range as large as the coverage area of

the service provider, no interference with other controllers and up

to twelve controlles.