/*
  Traffic Light with stop request
 
  This example code is in the public domain.
  
  made by @syxanash on 24/05/2012
*/

// defining some notes

#define NOTE4  262
#define NOTE5  523
#define NOTE6  784

int speaker = 3;

// delays for the traffic lights transitions

int delays[] = { 4000, 2000 };

int leds[]   = { 10, 11, 12, 12, 10 };
int leds2[]  = { 9, 9, 7, 8, 9 };

int stoprequest = 2;
int stopflagled = 4;

void setup() {
  Serial.begin(9600);  

  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);

  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);

  pinMode(stopflagled, OUTPUT);

  pinMode(speaker, OUTPUT);

  pinMode(stoprequest, INPUT);
  digitalWrite(stoprequest, HIGH);
}

// function which checks the request made by the pedestrian

boolean checkrequest (boolean flag) {

  if ( digitalRead( stoprequest ) == LOW && flag != true ) {
    flag = true;
    
    // turn on a check led

    digitalWrite(stopflagled, HIGH);
    
    // and print into serial port a notification

    Serial.println( "A pedestrian pushed a stop request" );
    
    // makes also a pretty nice sound notification

    tone(speaker,NOTE4,0);
    delay(100);
    tone(speaker,NOTE5,0);
    delay(100);
    tone(speaker,NOTE6,0);
    delay(100);
    noTone(speaker);
  }

  return flag;
}

void loop() {

  boolean flag = false;

  for ( int i = 0; i < 5; i++ ) {

    flag = checkrequest( flag );

    digitalWrite(leds[i], HIGH);
    digitalWrite(leds2[i], HIGH);

    Serial.print("Pedestrian: ");
    Serial.println( leds[i] );

    Serial.print("Vehicles: ");
    Serial.println( leds2[i] );
    
    // if the pedestrian pushed a stop request the delay
    // decrements of 1 second, else it makes a standard delay

    if ( flag == true && leds[i] == 12 ) {
      delay(1000);
    }
    else {
      delay(delays[i % 2]);
    }

    digitalWrite(leds2[i], LOW);
    digitalWrite(leds[i], LOW);
  }

  // turn off the check led for the stop request

  digitalWrite(stopflagled, LOW);
}