Cell phone operated Land Rover

Abstract: - you may have seen so many land rover projects on different websites or even on multyremotes.com as moon-walker and robo-vehicle. most probably they are remote controlled (either IR or RF) or they may be automatic guided vehicles (AGV). this is also remote controlled land rover but as a remote control one can use his cell phone. that means he can move the land rover by sending different commands from his cell phone. not only that, he can control it form any where in the world (of course where GSM / CDMA network is available).

This concept is taken from military application where such land rover works as Unmanned Guided vehicle (UGV) for spy operations, mine diffuser, bomb detector etc. in such application the movements of land rover can be controlled from very far remote and safe place (as there is practically no limitation on operating range)

Here I have develop very simple application in which the land rover moves forward, backward and takes left or right turn as per commands given from any cell phone but one can develop any interesting application over this platform like given above.

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Let us start with mechanical assembly of land rover.

Mechanical Assembly: -

As shown in above figure four wheels are attached with chassis made up of any metal (like iron). Shaft of two DC motors (around 150 RPM or more) are directly coupled with real wheels. So as both motors rotate CW, the land rover moves forward. And as both motors rotate CCW, it will move backward. to turn it left right DC motor rotates and to turn it right left DC motor rotates. Also it will take forward-left & forward-right turn as well as backward-left & backward-right turn if required. For that, either of the motors (left or right) is rotated CW or CCW. For example if left motor rotates CW, land rover will take forward-right turn and if it rotates CCW then backward-right turn. Similarly for right DC motor.

Now let us see the block diagram of system 

System Block diagram: -

The major building blocks are cell phone, DTMF decoder, micro-controller, DC motor driver circuits.

Cell phone: - This is very first and the most important part of the system because due to this only the entire system is activated and works. It will receive the signals from another cell phone and gives them as input to DTMF decoder. First the system is activated by calling the SIM card number inside the phone. Afterwards it will receive DTMF code signals dialed from another cell phone and gives it to DTMF decoder.

DTMF decoder: - The function of this block is self understood. It will take DTMF input given by cell phone decode it and gives 4-bit digital output to micro controller. It also generates an interrupt every time when it gives digital output

Micro-controller: - You can call this block as the heart of entire system because it actually performs all the controlling actions. Depending upon the code given by DTMF decoder it will move the rover forward, backward, left or right by rotating both DC motors

DC Motor driver: - It receives actuating signals from micro controller in terms of high / low logic, amplifies (current) it and rotates 2 DC motors in both directions

go to next page for  controlling circuit