The document describes a driverless car (robot) that is controlled by a mobile phone. The mobile phone attached to the robot receives DTMF tones from the controlling phone when buttons are pressed. These tones are processed by the robot's microcontroller using a DTMF decoder chip to determine which button was pressed. DTMF assigns specific frequencies to each button so they can be identified electronically. The robot has advantages of wireless control from anywhere in the world with no range limit since it uses mobile technology. Potential applications include using remote controlled vehicles for scientific research, military and law enforcement situations, and search and rescue operations.

1. DRIVER LESS CAR(robot)
Prepared
by :
Afnan Ali Khan
(10-EE-106)
Atif Akthar
(10-EE-110)
Fazal Fawad
(10-EE-161)
GUIDED BY:
Engr. Hassan Bhatti

2. Project overview
In this project, the robot is controlled by a mobile phone that
makes a call to the mobile phone attached to the robot. In the course
of a call, if any button is pressed, a tone corresponding to the button
pressed is heard at the other end of the call. This tone is called ‘dualtone multiple-frequency’ (DTMF) tone.
The robot perceives this DTMF tone with the help of the phone
stacked in the robot.
The received tone is processed bythe microcontroller with the help
of DTMF decoder MT8870.

3. BLOCK DIAGRAM

4. CIRCUIT DIAGRAM

5. PIN DIAGRAM

6. IC 8870

7. A DTMF TELEPHONE KEYPAD
The contemporary keypad is laid out in a 3×4 grid,
although the original DTMF keypad had an additional column for four
now-defunct menu selector keys. When used to dial a telephone
number, pressing a single key will produce a pitch consisting of two
simultaneous pure tone sinusoidal frequencies. The row in which the
key appears determines the low frequency, and the column
determines the high frequency. For example, pressing the '1' key
will result in a sound composed of both a 697 and a 1209 hertz (Hz)
tone. The original keypads had levers inside, so each button
activated two contacts. The multiple tones are the reason for calling
the system multi-frequency. These tones are then decoded by the
switching center to determine which key was pressed.

8. DTMF
The mobi le that makes a call to the mobile phone stacked in the
robot acts as a remote. So this simple robotic project does not require
the construction of receiver and transmitter units. DTMF signaling is
used for telephone signaling over the line in the voice-frequency band
to the call switching centre. The version of DTMF used for telephone
tone dialing is known as ‘Touch-Tone.’
DTMF assigns a specific frequency (consisting of two separate tones)
to each key so that it can easily be identified by the electronic circuit.
The signal generated by the DTMF encoder is a direct algebraic
summation, in real time, of the amplitudes of two sine (cosine) waves
of different frequencies, i.e., pressing ‘5’ will send a tone made by
adding 1336 Hz and 770 Hz to the other end of the line. The tones
and assignments in a DTMF system are shown in Table I.

10. ADVANTAGES
1. Wireless control
2.There is no range limit as we can control from anywhere in the world.
3. Takes in use of the mobile technology which is almost available
everywhere.

11. APPLICATIONS
1) SCIENTIFIC
Remote control vehicles have various scientific uses including
working in hazardous environments, deep ocean, and space
exploration.
2)MILITARY AND LAW ENFORCEMENT
Usage of remotely controlled military vehicles in the Winter War .
3) SEARCH AND RESCUE
Robot will likely play an increased role in search and rescue in the
future.