Microprocessor Based Control of Traffic Lights

7/23/2019 Microprocessor Based Control of Traffic Lights

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TERM PAPER OF

MICROPROCESSOR

TOPIC

:MICROPROCESSOR BASED CONTROL

OF TRAFFIC LIGHTS

SUBMITTED TO: SUBMITTED BY:

Ms. Gaganpreet Kaur Rishab MehtaLect. In ECE Btech-MBA (CSE)LPU Reg. No-3450070062

Section-D1703Roll no. -51


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CONTENTS

INTRODUCTIONDESCRIPITIONASSEMBLY LANGUAGE PROGRAMPROCEDUREBIBLIOGRAPHY

INTRODUCTION

A microprocessor has been incorporated into a

traffic light simulator. It is being used to teach

undergraduate industrial engineers about software

development and basic concepts of interfacing. Thesimulator combines hardware, software, and

documentation into a compact portable package

which can be locally constructed. It provides a

useful part of the study program required to develop

the skills industrial engineers need for industrial

control.

The main aim of this project is to design a

Traffic light controller using 8085 microprocessor.

The 8085 Microprocessor is a popular

Microprocessor used in Industries for various

applications. Such as traffic light control,

temperature control, stepper motor control, etc. In

this project, the traffic lights are interfaced to

Microprocessor system through buffer and ports of

programmable peripheral Interface 8255. So the

traffic lights can be automatically switched

ON/OFF in desired sequence. The Interface board

has been designed to work with parallel port of

Microprocessor system.

The hardware of the system consists of two

parts. The first part is Microprocessor based system

with 8085. Microprocessor as CPU and the

peripheral devices like EPROM, RAM, Keyboard

& Display Controller 8279, Programmable as

Peripheral Interface 8255, 26 pin parallel port

connector, 21 keys Hexa key pad and six number of

seven segment LEDs.

The second part is the traffic light controller

interface board, which consist of 36 LEDs in

which 20 LEDs are used for vehicle traffic and

they are connected to 20 port lines of 8255 through

Buffer. Remaining LEDs are used for pedestrian

traffic. The traffic light interface board is

connected to Main board using 26 core flat cables

to 26-pin Port connector. The LEDs can be

switched ON/OFF in the specified sequence by the

Microprocessor.

The block diagram of the system is shown in fig.1. The lay out of the traffic light is shown in fig 2.

Traffic light interface board

8085CPU

Latch 8255PPI

26pinportconnector

26pinportconnector

Buffer AD

0-AD

7A

0-A

7

26 pinFRC cable

D0-

D7

System Bus

EPROM RAM8279

keyboardDisplay

Controller

Anode driver

Decoder Keyboard Cathode driver

Display


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FIG.2: LAYOUT OF TRAFFIC LIGHTS

a primary object of the invention to provide a

traffic light control and information transmission

device that applies the existing broadband network

to transmit data between the central traffic controlcomputer and themicroprocessors of the cross roads

to avoid the installation of the cables and save the

construction cost.

In order to achieve the objective set forth, a traffic

light control and information transmission device in

accordance with the present invention comprises amicroprocessor on the cross road, the

microprocessor further connects to a traffic

lightcontroller, an electronic display board, a video

camera, a compression circuitry, an I/O interface, a

traffic flow detector and connected to the central

traffic control computer through the DSL (DigitalSubscriber Loop). The control signals, traffic,public

information or news of the central traffic control

computer can go through the DSL to the

microprocessor; the microprocessor can control the

traffic light and display all the information on the

electronic display board. The traffic flow data ofthe

cross roads can be accessed by the traffic flowdetector and the video camera and transmitted back

to the central traffic control computer.

Fig 1: Block diagram of Traffic Light Controller

StopPW

StopPW

Stop PN Stop PNStopPE

StopPE

GoPW

Stop PS

Go PS

Stop PS

Go PS

GoPE

GoPW

Go PN Go PN GoPE

NORTH

SOUTH

EAST

WEST

StopW

WarningW

GoW

FRW

FLW

STW

Stop NWarning N

Go NFR N FL NST N

Stop S

Warning S Go S

FR SST SFL S

StopE

WarningE

FRE

FLE

STE


4/8

FIG 1 is a circuit block diagram of the present

invention;

FIG. 2 is a flowchart of the present invention.

DESCRIPTION OF THE PREFERRED

EMBODIMENT

Referring to FIG. 1, the components of the present

invention are described below:

The microprocessor 1 is inside the traffic control

box of the traffic light and to control all the

circuitries.The traffic light controller 2 is connected to and

controlled by the microprocessor 1 to send out the

stop, go and direction signals.

The electronic display board 3 is connected to and

controlled by the microprocessor 1 to display

characters, patterns and graphic images.

The video camera 4 is connected to and controlled by the microprocessor 1 to monitor the traffic flow.

The compression circuitry 5 connects to the

microprocessor 1 and the video camera 4, the

compression circuitry 5 compresses the image data

captured by the video camera 4 and sends the

compressed data to the microprocessor 1.

The I/O interface 6 connects to the microprocessor

1 and receives, transmits data and control signals.

The traffic flow detector 7 connects to the I/O

interface 6 and gathers the traffic flow information;

the traffic flow information is input to the

microprocessor 1.

The DSL (Digital Subscriber Loop) 8 connects to

the I/O interface 6 and receives, transmits data and

control signals.

The broadband network 9 links the DSL 8 and the

central traffic control computer 91 together; the

central traffic control computer 91 sends and

receives the data and controls signals to the

microprocessor through the broadband network 9.

The video camera 4 can be a picture camera; the

DSL 8 can be a cable modem, ADSL, VDSL, or

XDSL as needed.

Based on above structure and referring to the flow

chart shown in FIG. 2, the traffic flow detector 7 on

the cross roads gather the traffic flow information

and pass the data to the microprocessor 1 through

the I/O interface 6; the video camera 4(or picture

camera) inputs the traffic flow images to the

compression circuitry 5, those data are converted

into digital signals by the compression circuitry 5

and input to the microprocessor 1. The DSL 8

transmits the data by the traffic flow detector7 and

the video camera 4 (or picture camera) through the

broadband network 9 to the central traffic control

computer 91, the central traffic control computer 91

calculates the best control timing for the traffic light

controller 2 and transmits the bestcontrol timing

through the broadband network 9, the DSL 8 (or

cable modem) receives the best control timing and

then transmits those to the microprocessor 1, the

microprocessor 1 can response accordingly to the

traffic light controller 2.

Based on above description, the communication between the microprocessor 1 on the cross roads

and the central traffic control computer 91 on the

central office is through the existing broadband

network 9, therefore this scheme can avoid

theinconvenience and tedious of the installation of

the cables; the installation, road work cost can be

minimized.

The traffic, public information or news can also go


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from the central traffic control computer 91 and

through the broadband network 9, the

microprocessor 1 on the cross roads can receive

those information and display those messages on

theelectronic display board 3, all the drivers can be

informed.

While a preferred embodiment of the invention has

been shown and described in detail, it will be

readily understood and appreciated that numerous

omissions, changes and additions may be made

without departing from the spirit and scope of

theinvention.

Vinytics Peripherals offers Microprocessor based

Traffic Light Controller Interface Module Card.

Vinytics Peripherals develops microprocessor and

PC based products for engineering colleges, science

colleges, polytechnics, test & measurement, process

control, industrial automation, medical,

instrumentation, intelligent graphic systems,

research laboratories, supervisory control and dataacquisition, telecommunication and production

facilities. The Interfacing Modules can be

connected to the lines of 8/16 bit Microprocessor or

Microcontroller Training kit to perform the

experiments in the laboratory that helps in learning

about real time interfacing problems of the

microprocessors or microcontroller TheMicroprocessor based Traffic Light Controller

Interface Module Card, VMC-TLC has RED,

YELLOW and GREEN LED`s to demonstrate the

use of Microprocessor in controlling the traffic

movement under the control of program. It is a

good example of use of Microprocessor in common

applications.

Traffic light controller interface module is designed

to simulate the function of four way traffic light

controller. Combinations of red, amber and green

LEDs are provided to indicate Halt, Wait and Go

signals for vehicles. Combination of red and green

LEDs are provided for pedestrian crossing. 36

LEDs are arranged in the form of an intersection.

A typical junction is represented on the PCB with

comprehensive legend printing.

At the left corner of each road, a group of five

LEDs (red, amber and 3 green) are arranged in the

form of a T-section to control the traffic of that

road. Each road is named North (N), South(S), East

(E) and West (W). LEDs L1, L10, L19 & L28

(Red) are for the stop signal for the vehicles on the

road N, S, W, & E respectively. L2, L11, L20 &

L29 (Amber) indicates wait state for vehicles on the

road N, S, W, & E respectively. L3, L4 & L5

(Green) are for left, strait and right turn for the

vehicles on road S. similarly L12-L13-L14, L23-

L22-L21 & L32-L31-L30 simulates same function

for the roads E, N, W respectively.

A total of 16 LEDs (2 Red & 2 Green at each road)

are provided for pedestrian crossing. L7-L9.L16-

L18, L25-L27 & L34-L36 (Green) when on allows

pedestrians to cross and L6-L8, L15-L17, L24-L26

& L33-L35 (Red) when on alarms the pedestrians towait.

To minimize the hardware pedestrians indicator

LEDs (both red and green are connected to same

port lines (PC4 to PC7) with red inverted. Red

LEDs L10 & L28 are connected to port lines PC2

& PC3 while L1 & L19 are connected to lines PC0

& PC1 after inversion. All other LEDs (amber and

green) are connected to port A


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& B.

ASSEMBLY LANGUAGE PROGRAMS:-

MODEL SMALL

.STACK 100

.DATA

CWR EQU 0FFC6 H

PORTA EQU 0FFC0 H

PORTB EQU 0FFC2 H

PORTC EQU 0FFC4 H

.CODE

START:

MOV AX,@DATAMOV DS,AX

MOV AL,80H

MOV DX,CWR

OUT DX,AL

MOV AL,F3H

MOV DX,PORTC

OUT DX,ALMOV AL,FFH

MOV DX,PORTA

OUT DX,AL

MOV AL,FFH

MOV DX,PORTB

OUT DX,AL

MOV CL,03H

CALL DELAY

TOP:

MOV AL,EEH

MOV DX,PORTA

OUT DX,AL

MOV AL,EEH

MOV DX,PORTB

OUT DX,AL

MOV CL,02H

CALL DELAY

MOV AL,FCH

MOV DX,PORTC

OUT DX,AL

MOV AL,7DH

MOV DX,PORTA

OUT DX,AL

MOV AL,57H

MOV DX,PORTBOUT DX,AL

MOV CL,15H

CALL DELAY

MOV AL,E7H

MOV DX,PORTB

OUT DX,ALMOV AL,FDH

MOV DX,PORTA

OUT DX,AL

MOV AL,EDH

MOV DX,PORTA

OUT DX,AL

MOV CL,02H

CALL DELAY

MOV AL,F7H

MOV DX,PORTB

OUT DX,AL

MOV AL,F0H

MOV DX,PORTC

OUT DX,AL

MOV AL,F1H


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MOV DX,PORTA

OUT DX,AL

MOV CL,15H

CALL DELAY

MOV AL,FBH

MOV DX,PORTA

OUT DX,AL

MOV AL,FBH

MOV DX,PORTB

OUT DX,AL

MOV AL,50H

MOV DX,PORTC

OUT DX,AL

MOV CL,15H

CALL DELAY

MOV AL,FEH

MOV DX,PORTA

OUT DX,AL

MOV AL,FEH

MOV DX,PORTB

OUT DX,AL

MOV CL,03H

CALL DELAY

MOV AL,FFH

MOV DX,PORTAOUT DX,AL

MOV AL,AFH

MOV DX,PORTC

OUT DX,AL

MOV AL,EEH

MOV DX,PORTA

OUT DX,AL

MOV AL,EEH

MOV DX,PORTB

OUT DX,AL

MOV CL,02H

CALL DELAY

MOV AL,BFH

MOV DX,PORTA

OUT DX,AL

MOV AL,BFH

MOV DX,PORTB

OUT DX,AL

MOV CL,15H

CALL DELAY

JMP TOP

DELAY:

MOV BX,10H

D1:

MOV CX,0FFFFH

D2:

LOOP D2

DEC BX

JNZ D1

INT 03HEND START

PROCEDURE:-

1. Connect power supply 5V & GND to both

microprocessor trainer kit & Traffic light controller interfacing kit.

2. Connect data bus between microprocessor trainer

kit & Traffic light controller interfacing kit.

3. Enter the program to control Traffic light.

4. Execute the program by typing GO E000:0B80ENTER.

5. Observe the LEDs on traffic light controller


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PCB.

BIBLIOGRAPHY

www.google.com

www.wikipedia.org

www.ask.com

www.bing.com

www.microprocessor.com
http://www.google.com/http://www.wikipedia.org/http://www.ask.com/http://www.bing.com/http://www.microprocessor.com/http://www.google.com/http://www.wikipedia.org/http://www.ask.com/http://www.bing.com/http://www.microprocessor.com/

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Microprocessor Based Control of Traffic Lights