4 Way Traffic Light Control System Circuit Diagram Using AT89C52 Microcontroller
Code Written By: Frank Donald | Circuit Animated by: Azhar Ahmed
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#include<stdio.h>
#include<reg51.h>
void delay(void);
void count1(void);
void count2(void);
sbit NR=P0^0; sbit NY=P0^1; sbit NG=P0^2; sbit NGL=P0^3; //Setting bit for LED's north
sbit SR=P0^4; sbit SY=P0^5; sbit SG=P0^6; sbit SGL=P0^7; //Setting Bit for LED's South
sbit ER=P1^0; sbit EY=P1^1; sbit EG=P1^2; sbit EGL=P1^3; //Setting Bit for LED's East
sbit WER=P1^4; sbit WEY=P1^5; sbit WEG=P1^6; sbit WEGL=P1^7; //Setting Bit for LED's West
unsigned char a[10]={0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x3f}; //Array for displaying digits on segment 1,2.......9,0
unsigned char b[7]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d}; //Array for displaying 0 to 6
unsigned int i,j,s,k; //Assigning Integers
void main() //Main program
{
NR=1; NY=1; NG=0; NGL=1; //I phase forward green for north lights
SR=1; SY=1; SG=0; SGL=1; //forward green for south lights
ER=0; EY=1; EG=1; EGL=1; //Red signal for east
WER=0; WEY=1; WEG=1; WEGL=1; //Red signal for west lights
{
count1(); //Calling out subroutine to display digits in 7 segment
}
NR=1; NY=1; NG=0; NGL=1; //I phase yellow signal
SR=1; SY=1; SG=0; SGL=1;
ER=1; EY=0; EG=1; EGL=1;
WER=1; WEY=0; WEG=1; WEGL=1;
{
count2(); //Calling out sub routine for displaying counts for yellow
}
NR=0; NY=1; NG=1; NGL=1; //II phase red signal for north lights
SR=0; SY=1; SG=1; SGL=1;
ER=1; EY=1; EG=0; EGL=1;
WER=1; WEY=1; WEG=0; WEGL=1;
{
count1();
}
NR=1; NY=0; NG=1; NGL=1; //II phase yellow lights for North and south
SR=1; SY=0; SG=1; SGL=1;
ER=1; EY=1; EG=0; EGL=1;
WER=1; WEY=1; WEG=0; WEGL=1;
{
count2();
}
NR=1; NY=1; NG=1; NGL=0; //III phase Green left for north and south
SR=1; SY=1; SG=1; SGL=0;
ER=0; EY=1; EG=1; EGL=1;
WER=0; WEY=1; WEG=1; WEGL=1;
{
count1();
}
NR=1; NY=1; NG=1; NGL=0; //III phase yellow lights
SR=1; SY=1; SG=1; SGL=0;
ER=1; EY=0; EG=1; EGL=1;
WER=1; WEY=0; WEG=1; WEGL=1;
{
count2();
}
NR=0; NY=1; NG=1; NGL=1; //IV phase Red signal for North and south
SR=0; SY=1; SG=1; SGL=1;
ER=1; EY=1; EG=1; EGL=0;
WER=1; WEY=1; WEG=1; WEGL=0;
{
count1();
}
NR=1; NY=0; NG=1; NGL=1; //IV phase Yellow signal for north and south
SR=1; SY=0; SG=1; SGL=1;
ER=1; EY=1; EG=1; EGL=0;
WER=1; WEY=1; WEG=1; WEGL=0;
{
count2();
}
}
void count1(void) //Sub routine for displaying numbers in segments for red signal
{
P2=0x3f;
for(j=0;j<=4;)
{
for(i=0;i<=8;)
{
P3=a[i];
i++;
delay();
}
j++;
P2=b[j];
P3=0x3f;
delay();
}
}
void count2(void) //Sub routine for displaying numbers in segments for yellow signal
{
P2=0x3f;
for(i=0;i<=8;)
{
P3=a[i];
i++;
delay();
}
P2=0x06;
P3=0x3f;
delay();
}
void delay(void) //Sub routine for creating delay
{
for(s=0;s<=230;s++) //Creating delay using number count
{
for(k=0;k<238;k++);
}
}