Haja

// Pin numbers are defined by the corresponding LED colors
#define RED_PIN 8 
#define YELLOW_PIN 10 
#define GREEN_PIN 12
//Define the delays for each traffic light color
int red_on = 6000; //3 s delay 
int green_on = 3000; //3 s delay
int yellow_blink = 500; //0.5 s delay Experiment 2 Lab Manual
© Dept. of EEE, Faculty of Engineering, American International University-Bangladesh (AIUB) 4
// Declaring the timer function to count 1 ms of delay instead of calling the delay function
int delay_timer (int milliseconds){
 int count = 0;
 while(1)
 {
 if(TCNT0 >= 15) // Checking if 1 millisecond has passed
 {
 TCNT0 = 0;
 count++; 
 if (count == milliseconds) //checking if required milliseconds delay has passed
 {
 count = 0;
 break; // exits the loop
 }
 }
 }
 return 0;
}
void setup() {
 //Define pins connected to LEDs as outputs
 pinMode(RED_PIN, OUTPUT); 
 pinMode(YELLOW_PIN, OUTPUT);
 pinMode(GREEN_PIN, OUTPUT);
 
 //Set up the Timer0
 TCCR0A = 0b00000000;
 TCCR0B = 0b00000101; //setting pre-scaler for timer clock
 TCNT0 = 0;
}
void loop() {
 //to make the green LED turned on
 digitalWrite(GREEN_PIN, HIGH);
 delay_timer(green_on);
 //to make the green LED turned off
 digitalWrite(GREEN_PIN, LOW);
 //for turning the yellow LED on and off for 4 times
 for(int i = 0; i < 4; i = i+1)
 {
digitalWrite(YELLOW_PIN, HIGH);
delay_timer(yellow_blink);
digitalWrite(YELLOW_PIN, LOW);
 delay_timer(yellow_blink);
 }
 
 //to make the red LED turned on
 digitalWrite(RED_PIN, HIGH); 
 delay_timer(red_on); 
 //to make the red LED turned off
 digitalWrite(RED_PIN, LOW); 
 }