DTMF based Mobile Controlled Robot

CONTENTS:

1. INTRODUCTION2. BLOCK DIAGRAM3. COMPONENTS DETAILS4. WORKING5. PRINCIPLE6. APPLICATIONS7. REFERENCE

INTRODUCTION:

THE robot, integrated with a mobile phone, forms the crux of this project. This integrated

architeture is controlled by a supplementary mobile phone, which initiates the call. Once the call is associated, any button pressed corresponds to a unique tone at the other end. The tone is termed as ‘Dual Tone Multiple Frequency’ (DTMF ) , which is perceived by the robot with the help of a cellular phone stacked in it. The received tone is fed into the DTMF decoder (CM8870), which decodes the DTMF tone into its equivalent binary. Binary output from the decoder is consequently administered by the microcontroller (P89V51RD2). 89V51RD2 is pre- programmed to take necessary decisions corresponding to the given set of binary inputs. Output from P89V51RD2 is provided to the drivers L293D and ULN2003. The former of which acts as a regulator to drive the DC motor while; the latter can be provided to drive the electrical appliances.

Cellular phone generating the call acts as a remote control obviating the need for construction of superfluous receiver and transmitter units and thus can be used for tele-control of electronic appliances.

BLOCK DIAGRAM:

REMOTE

MOBILE

MOBILE PHONE

MT8870

DTMF DECODER

P89V51RD2 MICROCONTROLLER

L293D MOTOR DRIVER

LEFT MOTOR

RIGHT MOTOR

LCD DISPLAY

WORKING :

As shown in the above block diagram, the first block is the cell phone. So, it acts as any DTMF generator with tone depending upon key pressed. DTMF decoder IC ,i.e., MT8870 decodes the received tones & gives binary equivalent of it to the microcontroller. The Microcontroller is programmed such that appropriate output given to the motor driver IC L293D which will drive the two DC Motors connected to it. The concept used for driving is “Differential Driver”. So ultimately the motors rotate according to the key pressed on the keypad of the cell phone.

In order to control the robot, you have to make a call to the cellphone attached to the robot from

any phone. 

now the phone is picked by the phone on the robot through autoanswer mode(which is in the

phn, just enable it). 

now when you press 2 the robot will move forward 

when you press 4 the robot will move left 

when you press 8 the robot will move backwards 

when you press 6 the robot will move right 

when you press 5 the robot will stop. 

APPLICATION :

Scientific.

Military and law Enforcement.

Search and Rescue.

Recreation and Hobby.

FURTHER IMPROVEMENTS AND FUTURE SCOPE :

IR Sensors. Password Protection. Alarm Phone Dialer. Adding a Camera.

REFERENCES :

Wikipedia –The free encyclopedia.

http : // www.8051projects.info /

http: // www.Instructables.com /

cellphone operated land roevleecrt r onics for you’ magazine, Edition (july 2008)

“DTMF Tester” ,” Electronics for you” magazine,Edition.