// A TRAFFIC LIGHT SYSTEM!!! by: Victoria Omega Gondwe

//Assigning the LED lights to their respective digital pins:
int Red=13;
int Yellow=12;
int Green=11;

//Initializing the digital pins as outputs through the assigned LED lights
void setup() {
  pinMode(Red, OUTPUT);
  pinMode(Yellow, OUTPUT);
  pinMode(Green, OUTPUT);
}

//declaring a function to change the lights in a loop of 1 minute, 25 seconds
void loop(){
  changeLights();
}


//Controlling the sequence of the system by calling the above declared function and then defining it. 
void changeLights() {
//The Red light(STOP) sequence
  //The loop will start with the Red light on, Cars will stop for 30 seconds while the Yellow and Green lights are off
  digitalWrite(Red,HIGH );
  delay(25000);


//The Yellow light(READY) sequence
  //The Red light will go off, Yellow will turn on 10 seconds and Cars will now get ready to GO
  digitalWrite(Red,LOW );
  digitalWrite(Yellow,HIGH );
  delay(10000);


//The Green light(GO) sequence
  //The Yellow and Red lights will now go off, Green light will turn for a minute(60 seconds) on Cars can now go
  digitalWrite(Yellow,LOW );
  digitalWrite(Green,HIGH );
  delay(40000);


//The Green light will now turn off so that the loop is complete, Then the Red light will turn on.
  digitalWrite(Green,LOW );
}