project.ino

#include<TimerOne.h>
#include <SPI.h>
#include <MFRC522.h>

#define RST_PIN         5          // Configurable, see typical pin layout above
#define SS_1_PIN        22         // Configurable, take a unused pin, only HIGH/LOW required, must be diffrent to SS 2
#define SS_2_PIN        23          // Configurable, take a unused pin, only HIGH/LOW required, must be diffrent to SS 1
#define SS_3_PIN        24
#define SS_4_PIN        25
#define NR_OF_READERS   4

byte ssPins[] = {SS_1_PIN, SS_2_PIN,SS_3_PIN,SS_4_PIN};
MFRC522 mfrc522[NR_OF_READERS];   // Create MFRC522 instance.
int signal1[] = {46,43,42,47};// Red,yellow,green,blue
int signal2[] = {40,39,38,41};
int signal3[] = {11,12,13,10};
int signal4[] = {7,8,9,6};
int i;
int redDelay = 5000;
int blueDelay = 4500;
int yellowDelay = 3000;
uint8_t reader=60;
volatile int triggerpin1 = 29;    
volatile int echopin1 = 28;       
volatile int triggerpin2 = 31;     
volatile int echopin2 = 30;        
volatile int triggerpin3 = 33;    
volatile int echopin3 = 32;       
volatile int triggerpin4 = 35;    
volatile int echopin4 = 34;       
volatile long time;                    // Variable for storing the time traveled
volatile int S1, S2, S3, S4;           // Variables for storing the distance covered

int t = 7;  // distance under which it will look for vehicles.

void setup(){
  Serial.begin(9600);
  SPI.begin();  
  Timer1.initialize(700000);  //Begin using the timer. This function must be called first. "microseconds" is the period of time the timer takes.
  Timer1.attachInterrupt(softInterr); //Run a function each time the timer period finishes.

  // Declaring LED pins as output
  for(int i=0; i<4; i++){
    pinMode(signal1[i], OUTPUT);
    pinMode(signal2[i], OUTPUT);
    pinMode(signal3[i], OUTPUT);
    pinMode(signal4[i], OUTPUT);
  }

  // Declaring ultrasonic sensor pins as output
  pinMode(triggerpin1, OUTPUT);  
  pinMode(echopin1, INPUT);      
  pinMode(triggerpin2, OUTPUT);  
  pinMode(echopin2, INPUT);
  pinMode(triggerpin3, OUTPUT);  
  pinMode(echopin3, INPUT);
  pinMode(triggerpin4, OUTPUT);  
  pinMode(echopin4, INPUT); 
   for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
    mfrc522[reader].PCD_Init(ssPins[reader], RST_PIN);} // Init each MFRC522 card
}

void loop()
{
   
     
  // If there are vehicles at signal 1
  if(S1<t)
  {
    signal1Function();
  }

  // If there are vehicles at signal 2
  if(S2<t)
  {
    signal2Function();
  }

  // If there are vehicles at signal 3
  if(S3<t)
  {
    signal3Function();
  }

  // If there are vehicles at signal 4
  if(S4<t)
  {
    signal4Function();
  }

}

// This is interrupt function and it will run each time the timer period finishes. The timer period is set at 100 milli seconds.
void softInterr()
{
  for (reader = 0; reader < NR_OF_READERS; reader++) {
    // Look for new cards

    if (mfrc522[reader].PICC_IsNewCardPresent() && mfrc522[reader].PICC_ReadCardSerial()) {
      Serial.print(F("Rfid reader "));
      Serial.print(reader);
      Serial.print(F(" detected.Calling  "));
      if(reader==0){signal1Function();blue1();}
      if(reader==1){signal2Function();blue2();}
      if(reader==2){signal3Function();blue3();}
      if(reader==3){signal4Function();blue4();}
    

      // Halt PICC
      mfrc522[reader].PICC_HaltA();
      // Stop encryption on PCD
      mfrc522[reader].PCD_StopCrypto1(); 
     
    } //if (mfrc522[reader].PICC_IsNewC
  } //for(uint8_t reader
 
  // Reading from first ultrasonic sensor
  digitalWrite(triggerpin1, LOW);  
  delayMicroseconds(2);
  digitalWrite(triggerpin1, HIGH); 
  delayMicroseconds(10);
  digitalWrite(triggerpin1, LOW);
  time = pulseIn(echopin1, HIGH); 
  S1= time*0.034/2;

  // Reading from second ultrasonic sensor
  digitalWrite(triggerpin2, LOW);  
  delayMicroseconds(2);
  digitalWrite(triggerpin2, HIGH); 
  delayMicroseconds(10);
  digitalWrite(triggerpin2, LOW);
  time = pulseIn(echopin2, HIGH); 
  S2= time*0.034/2;

  // Reading from third ultrasonic sensor
  digitalWrite(triggerpin3, LOW);  
  delayMicroseconds(2);
  digitalWrite(triggerpin3, HIGH); 
  delayMicroseconds(10);
  digitalWrite(triggerpin3, LOW);
  time = pulseIn(echopin3, HIGH); 
  S3= time*0.034/2;

  // Reading from fourth ultrasonic sensor
  digitalWrite(triggerpin4, LOW);  
  delayMicroseconds(2);
  digitalWrite(triggerpin4, HIGH); 
  delayMicroseconds(10);
  digitalWrite(triggerpin4, LOW);
  time = pulseIn(echopin4, HIGH); 
  S4= time*0.034/2;

 
}

void signal1Function()
{
  Serial.println("signal 1");
  low();
  // Make RED LED LOW and make Green HIGH for 5 seconds
  digitalWrite(signal1[0], LOW);
  digitalWrite(signal1[2], HIGH);
  delay(redDelay);
  // if there are vehicels at other signals
  if(S2<t || S3<t || S4<t)
  {
    // Make Green LED LOW and make yellow LED HIGH for 2 seconds
  digitalWrite(signal1[2], LOW);
  digitalWrite(signal1[1], HIGH);
  delay(yellowDelay);
  }
}

void signal2Function()
{
  Serial.println("signal 2");
  low();
  digitalWrite(signal2[0], LOW);
  digitalWrite(signal2[2], HIGH);
  delay(redDelay);
  if(S1<t || S3<t || S4<t)
  {
  digitalWrite(signal2[2], LOW);
  digitalWrite(signal2[1], HIGH);
  delay(yellowDelay);   
  }
}

void signal3Function()
{
  Serial.println("signal 3");
  low();
  digitalWrite(signal3[0], LOW);
  digitalWrite(signal3[2], HIGH);
  delay(redDelay);
  if(S1<t || S2<t || S4<t)
  {
  digitalWrite(signal3[2], LOW);
  digitalWrite(signal3[1], HIGH);
  delay(yellowDelay);
  }  
}

void signal4Function()
{
  Serial.println("signal 4");
  low();
  digitalWrite(signal4[0], LOW);
  digitalWrite(signal4[2], HIGH);
  delay(redDelay);
  if(S1<t || S2<t || S3<t)
  {
  digitalWrite(signal4[2], LOW);
  digitalWrite(signal4[1], HIGH);
  delay(yellowDelay);
  }
}

// Function to make all LED's LOW except RED one's.
void low()
{
  for(int i=1; i<3; i++)
  {
    digitalWrite(signal1[i], LOW);
    digitalWrite(signal2[i], LOW);
    digitalWrite(signal3[i], LOW);
    digitalWrite(signal4[i], LOW);
  }
  for(int i=0; i<1; i++)
  {
    digitalWrite(signal1[i], HIGH);
    digitalWrite(signal2[i], HIGH);
    digitalWrite(signal3[i], HIGH);
    digitalWrite(signal4[i], HIGH);
  }
}
void blue1()
{
    for(i=0;i<20;i++){
      digitalWrite(signal1[3], LOW);
      delay(blueDelay);
      digitalWrite(signal1[3], HIGH);
      delay(blueDelay);
      digitalWrite(signal1[3], LOW);
    }
    Serial.print(F("blue1 "));
    
}
void blue2()
{
        for(i=0;i<20;i++){
      digitalWrite(signal2[3], LOW);
      delay(blueDelay);
      digitalWrite(signal2[3], HIGH);
      delay(blueDelay);
      digitalWrite(signal2[3], LOW);
    }
    Serial.print(F("blue2 "));
}
void blue3()
{
    for(i=0;i<20;i++){
      digitalWrite(signal3[3], LOW);
      delay(blueDelay);
      digitalWrite(signal3[3], HIGH);
      delay(blueDelay);
      digitalWrite(signal3[3], LOW);
    }
    Serial.print(F("blue3 "));
}
void blue4()
{
    for(i=0;i<20;i++){
       digitalWrite(signal4[3], LOW);
     delay(blueDelay);
    digitalWrite(signal4[3], HIGH);
    delay(blueDelay);
    digitalWrite(signal4[3], LOW);
    }
    Serial.print(F("blue4 "));
    
}