8051 MICROCONTROLLER 8051 MICROCONTROLLER AND AND

EMBEDDED SYSTEMEMBEDDED SYSTEM

Submitted to:-Submitted to:-

Er. Radhe ShyamEr. Radhe Shyam

Submitted by:-Ankita AggarwalRoll No. 1609211

ContentContent

Introduction to Embedded systemIntroduction to Embedded system Introduction to microcontroller & Introduction to microcontroller &

microprocessorsmicroprocessors Introduction to DTMFIntroduction to DTMF Snapshot of the projectSnapshot of the project Working of the projectWorking of the project DTMF ModuleDTMF Module 8051 Module8051 Module H-Bridge ModuleH-Bridge Module

What is an Embedded System?What is an Embedded System?

An Embedded System is some combination of An Embedded System is some combination of hardware and software, either fixed in capability hardware and software, either fixed in capability or programmable that is specially designed for a or programmable that is specially designed for a particular function.particular function.

Components that can be used with the system are:

Microprocessor Sensors Converters (A/D or D/A) Actuators Memory

Application AreaApplication Area

Automotive ElectronicAutomotive Electronic

Aircraft ElectronicsAircraft Electronics

TrainsTrains

TelecommunicationTelecommunication

MicrocontrollerMicrocontroller

A small computerA small computer On-chip RAM, ROM, I/O portsOn-chip RAM, ROM, I/O ports ExampleExample ：： Motorola’s 6811, Intel’s 8051 and PIC 16XMotorola’s 6811, Intel’s 8051 and PIC 16X RAM is of 128 & ROM is of 4k bytesRAM is of 128 & ROM is of 4k bytes Number of I/O pins are 32Number of I/O pins are 32 Number of serial port is 1Number of serial port is 1 Number of interrupt sources are 6Number of interrupt sources are 6 Contains two bit 16 timer/counterContains two bit 16 timer/counter

CPUCPU RAMRAM ROMROM

I/O PORTI/O PORT TimerTimer SerialSerial

ComCom

portport

Single chip

Microprocessor V/s microcontrollerMicroprocessor V/s microcontroller

CPU stands alone, CPU stands alone, RAM, Rom, I/O are RAM, Rom, I/O are separateseparate

Designer can decide Designer can decide on the amount of on the amount of RAM, ROM, I/O RAM, ROM, I/O devicesdevices

ExpansiveExpansive VersatilityVersatility General purposeGeneral purpose

CPU, RAM, ROM & CPU, RAM, ROM & timer all are on a timer all are on a single chipsingle chip

Fix amount of on chip Fix amount of on chip RAM, ROM & I/O RAM, ROM & I/O partsparts

CheaperCheaper Single purposeSingle purpose

For example, if you want to design a computer, a For example, if you want to design a computer, a microprocessor is a better choice, but it can be also microprocessor is a better choice, but it can be also done with a microcontroller, the design and programming done with a microcontroller, the design and programming will be harder and perhaps more costly, the performance will be harder and perhaps more costly, the performance will not reach the microprocessor performance.will not reach the microprocessor performance.

In the other hand, if you want a circuit to control a single In the other hand, if you want a circuit to control a single home appliance, you do not have to use a powerful home appliance, you do not have to use a powerful microprocessor like Pentium with megabytes of RAM, microprocessor like Pentium with megabytes of RAM, etc . A simple but efficient microcontroller can do the etc . A simple but efficient microcontroller can do the same task for a minimum cost and more efficient design.same task for a minimum cost and more efficient design.

Microcontroller or MicroprocessorMicrocontroller or Microprocessor

DTMFDTMF

. DTMF signaling is used for telephone signaling . DTMF signaling is used for telephone signaling over the line in the voice frequency band to the over the line in the voice frequency band to the call switching center.call switching center.

The version of DTMF used for telephone dialing The version of DTMF used for telephone dialing is known as touch tone. DTMF assigns a specific is known as touch tone. DTMF assigns a specific frequency (consisting of two separate tones) to frequency (consisting of two separate tones) to each key so that it can easily be identified by the each key so that it can easily be identified by the electronic circuit. electronic circuit.

Snapshot of the projectSnapshot of the project

Block Diagram of DTMFBlock Diagram of DTMF

697 Hz

770 Hz

852 Hz

941 Hz

1209 Hz

1336 Hz

1477 Hz

RowSelector

ColumnSelector

+Desired signal

Dual tone

Working of the robotWorking of the robot

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 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 tone (DTMF). Based on this tone received the robot takes the appropriate action.

The received tone is processed by the AT89S52 microcontroller with the help of DTMF decoder IC8870.

Function of the keysFunction of the keys

On pressing On pressing 22, the robot will move , the robot will move forwardforward..

On pressing On pressing 44, the robot will move , the robot will move leftleft.. On pressing On pressing 66, the robot will move , the robot will move rightright.. On pressing On pressing 88, the robot will move , the robot will move backwardsbackwards..

On pressing On pressing 55, the robot will , the robot will stopstop..

Interfacing motor using H-bridgeInterfacing motor using H-bridge

H bridge is a circuit H bridge is a circuit topology that allows topology that allows bidirectional control of bidirectional control of motormotor

Contains four switchesContains four switches Alternative switches are Alternative switches are

closed at a timeclosed at a time Usually H bridge is used Usually H bridge is used

to reverse the polarity of to reverse the polarity of a motora motor

Switches are not closed Switches are not closed simultaneously as this will simultaneously as this will lead to short circuitlead to short circuit

motor

+externalvoltage

-

DTMF ModuleDTMF Module

This module has been used to decode the This module has been used to decode the signals received from the cell phone and to pass signals received from the cell phone and to pass these decoded signals to the 8051 module.these decoded signals to the 8051 module.

1209 Hz1209 Hz 1336 Hz 1336 Hz 1447 Hz 1447 Hz

697 Hz697 Hz 1 1 2 2 3 3

770 Hz770 Hz 4 4 5 5 6 6

852 Hz 852 Hz 7 7 8 8 9 9

941 Hz 941 Hz * * 0 0 # #

Snapshot of DTMF ModuleSnapshot of DTMF Module

Snapshot of 8051 moduleSnapshot of 8051 module

8051 Module is the brain of the project.

H-Bridge ModuleH-Bridge Module

This module is the motor driver circuit. It drives This module is the motor driver circuit. It drives the motors forward or backward on the basis of the motors forward or backward on the basis of signals received from the 8051 module .signals received from the 8051 module .

The H-Bridge arrangement is generally used to The H-Bridge arrangement is generally used to reverse the polarity of the motor, but can also be reverse the polarity of the motor, but can also be used to 'brake' the motor, where the motor used to 'brake' the motor, where the motor comes to a sudden stop, as the motor's comes to a sudden stop, as the motor's terminals are shorted, or to let the motor 'free terminals are shorted, or to let the motor 'free run' to a stop.run' to a stop.

Snapshot of the H-Bridge ModuleSnapshot of the H-Bridge Module

Software used Software used

software used for burning software used for burning

Data written on the chip looks likeData written on the chip looks like

For the co-operation……