Folks! Here is a very interesting take on robotics. A Land Rover which can be operated wirelessly using your cellphone or you may also call it a remote controlled robot where the remote need not be any added device but your much used mobile phone. This means you can operate this robot even when you are miles away. Yes, the idea behind is really commendable. It can be deployed in areas where human access is not possible like nuclear reactors, for military applications, as unmanned guide vehicles for spy operations, mine diffuser, bomb detector etc.
The mechanical assembly contains a metal chasing, two rear wheels, two front wheels and two DC motors fitted at the rear wheels each. The direction of rotation of the motor’s shaft determines the direction in which the rover moves. 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 take a look at how does this system communicates with a cell phone. Basically, two cell phones are required for this purpose; one at the user’s end and another at the rover’s end. The user first dials the number of the subscriber identity module in the cell phone at the rover’s end to access control over the system. The mobile phone keypad is used to control the robot. Each key on the keypad is assigned a particular function as per the user. These signals are decoded at the receiver side using a DTMF decoder. The decoded signals are given to the microcontroller which interprets the control signal and drives the motor consequently.