Description
It’s a 2-Way Traffic Signal Controller using 8051 microcontroller. It controls 6 lights (2 red, 2 yellow and 2 green) for 2-Way Traffic. It is an interesting and another basic learning project for student and hobbies.
Circuit Diagram
Detail
In this project 8051 microcontroller controls 6 traffic lights of 2-Way traffic. A fixed time is assigned to each green signal of each way. This is also simple project that uses 6 LEDs of 3 colors, 8051 microcontroller and an optional 5V power supply regulator part. It’s algorithm is as follows
1- Initially microcontroller switches on both red LED lights of both ways and switches off all other LED lights of both ways.
2- Then wait for time defined by RESET_DELAY.
3- Now start servicing way 0 by switching yellow LED light of that way. Give delay of defined by YELLOW_DELAY.
4- Now switch off red and yellow LED lights of way 0 and switch on green of that way. Wait for green way 0 as defined by GREEN0_DELAY.
5- Switch off green and switch on yellow LED light for way 0. Give delay of defined by YELLOW_DELAY.
6- Switch off yellow and switch on red LED lights for way 0. Give delay of defined by RED_DELAY.
7- Now servicing of way 0 is complete and it is the time to service 2nd way that is way 1. Similarly we repeat steps from 2 to 6 for way 1 also.
8- After servicing of way 1 we once again start from way 0 as discussed earlier.
For basic operation & components used in an 8051 microcontroller based systems see
8051 Basic LED Flasher.
Code
// Start of code.
///////////////////////////////////////////////////////////
// Company : Micro Digital //
// Address : Office # C7 Raza Plaza //
// DAV College Road //
// Rawalpindi, //
// Pakistan. //
// Programmed By : Rashid Mehmood //
// Project Name : 2-Way Traffic Light Controller //
// Crystal : 24.000000 MHz //
// Microcontroller : AT89C2051-C51-C52-C55-S2051-S51-S52 //
///////////////////////////////////////////////////////////
// Header file for AT89x051 microcontrollers regiter definitions.
#include <AT89x051.h>
sbit R0 = P1^0;
sbit Y0 = P1^1;
sbit G0 = P1^2;
sbit R1 = P1^3;
sbit Y1 = P1^4;
sbit G1 = P1^5;
void delay_ms(unsigned int del)
{
unsigned int i,j;
for(i = 0; i < del; i ++)
for(j = 0; j < 1275; j ++);
}
#define RESET_DELAY 1000 // (aprox 1 second)
#define RED_DELAY 1000 // (aprox 1 second)
#define YELLOW_DELAY 1000 // (aprox 1 second)
#define GREEN0_DELAY 2000 // (aprox 2 second)
#define GREEN1_DELAY 3000 // (aprox 3 second)
void main()
{
// Initialize all lights////////
// Switch on all red signals.
R0 = R1 = 0;
// Switch off all other signals.
Y0 = Y1 = G0 = G1 = 1;
delay_ms(RESET_DELAY);
////////////////////////////////
while(1)
{
// First service way 0.////////////////////
// Switch on yellow of way 0.
Y0 = 0;
delay_ms(YELLOW_DELAY);
// Switch off red and yellow of way 0 and
// switch on green of way 0.
R0 = 1;
Y0 = 1;
G0 = 0;
delay_ms(GREEN0_DELAY);
// Switch off green of way 0 and
// switch on yellow of way 0;
G0 = 1;
Y0 = 0;
delay_ms(YELLOW_DELAY);
// Switch off yellow of way 0 and
// switch on red of way 0;
Y0 = 1;
R0 = 0;
delay_ms(RED_DELAY);
/////////////////////////////////////////
// Now service way 1.////////////////////
// Switch on yellow of way 1.
Y1 = 0;
delay_ms(YELLOW_DELAY);
// Switch off red and yellow of way 1 and
// switch on green of way 1.
R1 = 1;
Y1 = 1;
G1 = 0;
delay_ms(GREEN0_DELAY);
// Switch off green of way 1 and
// switch on yellow of way 1;
G1 = 1;
Y1 = 0;
delay_ms(YELLOW_DELAY);
// Switch off yellow of way 1 and
// switch on red of way 1;
Y1 = 1;
R1 = 0;
delay_ms(RED_DELAY);
/////////////////////////////////////////
}
}
// End of code.
This code can also be executed on AT89C2051 microcontroller a small brother of AT89C51.