/* NOTE: DEMO ONLY!!
Do not attempt to power this many LEDS from the board
*/
int latchPin = 8;//Pin connected to ST_CP of each shift register
int clockPin = 12;  //Pin connected to SH_CP of each shift register
int dataPin = 11; //Pin connected to DS of first shift register
// Connect Q7S of the first shift register to DS of the next register(s)

int pirPin = 7;
int flagTripped = 0;
int pir = 0;


// Some timer stuff for the sensor simulation
unsigned long startMillis; 
unsigned long currentMillis;
const unsigned long period = 5000;

int interval = 5000; // Set the number dwell time before changing

/* 
Shift registrs are arranged so one controls E/W the other controls N/S
The order in which you shift the bytes into the register dictates which direction gets the sequence

B00100100 (36) = E/W Green if used as first byte, N/S Green if second byte
B10010000 (144)= N/S Red (first), E/W red (second)
B01001000 (72)= E/W Orange (first), N/S Orange (second)

WR,WO,WG,ER,EO,EG,0,0

NR,NO,NG,SR,SO,SG,0,0
*/  
  
void setup() 
{
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  pinMode(pirPin, INPUT);
  Serial.begin(9600);
  changeLights(36,144); // Set E/W green, N/S Red
  Serial.println("East/West on green");
}

void loop(){
  pir = digitalRead(pirPin);
  
  // If motion detected,set the change sequence in action
  if(pir == 1 && flagTripped == 0){
    flagTripped = 1;
     Serial.println("East/West ready to stop");
    changeLights(72,144); // Change E/W to orange, keep N/S Red
    delay(interval/2);
    Serial.println("All stop");
    changeLights(144,144); // Both sets red
    delay(interval/2);
    Serial.println("North/South on green");
    changeLights(144,36); // Change E/W to red, N/S green
    startMillis = currentMillis = millis(); // Start the sensor timer
    }

  // Simulate the sensor reset timeout - Not needed in real life due to onboard timer
  while(currentMillis - startMillis <= period){
    if(digitalRead(pirPin)==1){
      //Reset timer if pir retriggered
      startMillis=currentMillis = millis();
    }
  currentMillis=millis();
  }
pir = 0;


    // If sensor no longer detecting, and the N/S traffic is on green
    // Start the change sequence to get E/W back on green
    if(pir==0 && flagTripped == 1){
      flagTripped = 0;
      Serial.println("North/South ready to stop");
      changeLights(144,72); // Change N/S to orange, keep E/W Red
      delay(interval/2);
      Serial.println("All stop");
      changeLights(144,144); // Both sets red
      delay(interval/2);
      Serial.println("East/West on green");
      changeLights(36,144); // Change E/W to green, N/S Red
    }
}


void changeLights(byte b1, byte b2){
    digitalWrite(latchPin, LOW);
    // West/East register
    shiftOut(dataPin, clockPin, LSBFIRST, b1); 
    // Nth/Sth register
    shiftOut(dataPin, clockPin, LSBFIRST, b2); 
    digitalWrite(latchPin, HIGH);
}