#include <Servo.h>
#include <LiquidCrystal_I2C.h>

int seconds = 0;              
int redled = 11;              
int yellowled = 12;          
int greenled = 13;
int red_pedestrian = 5;
int green_pedestrian = 6;

LiquidCrystal_I2C lcd(0x27, 16, 2); 
Servo servo_motor;             

void setup() {
  lcd.begin(16, 2);            
  servo_motor.attach(9, 500, 2500); 
  pinMode(redled, OUTPUT);     
  pinMode(yellowled, OUTPUT);  
  pinMode(greenled, OUTPUT);  
}

void loop() {            
  lcd.setBacklight(1);
  initial_display();            
  delay(2000);                 
  lcd.clear();

  red_for_stop();
  countdown(60);                
  lcd.clear();

  green_for_go();
  countdown(60);               
  lcd.clear();

  yellow_for_wait();
  countdown(5);                
  lcd.clear();    
}

void red_for_stop() {
    digitalWrite(redled, HIGH);   
    digitalWrite(greenled, LOW); 
    digitalWrite(yellowled, LOW); 
  	digitalWrite(red_pedestrian, LOW);
  	digitalWrite(green_pedestrian, HIGH);
    lcd.setCursor(0, 0);          
    lcd.print("STOP!");          
    barrier_stop();           
}

void yellow_for_wait() {
    digitalWrite(redled, LOW);   
    digitalWrite(greenled, LOW);  
    digitalWrite(yellowled, HIGH);
  	digitalWrite(red_pedestrian, LOW);
 	digitalWrite(green_pedestrian, HIGH);
    lcd.setCursor(0, 0);         
    lcd.print("WAIT!");        
    barrier_stop();           
}

void green_for_go() {
    digitalWrite(redled, LOW);    
    digitalWrite(greenled, HIGH); 
    digitalWrite(yellowled, LOW); 
  	digitalWrite(green_pedestrian, LOW);
  	digitalWrite(red_pedestrian, HIGH);
    lcd.setCursor(0, 0);          
    lcd.print("GO!");            
    barrier_go();               
}

void countdown(int start_seconds) {
    for (int seconds = start_seconds; seconds >= 1; seconds--) { 
        lcd.setCursor(0, 1);      
        if (seconds < 10) {
            lcd.print(" ");
        }
        lcd.print(seconds);       
        delay(1000);             
    }
}

void initial_display() {
    digitalWrite(redled, LOW);    
    digitalWrite(greenled, LOW); 
    digitalWrite(yellowled, LOW); 
    lcd.setCursor(0, 0);
    lcd.print(" TRAFFIC LIGHT");
    lcd.setCursor(0, 1);
    lcd.print("    SYSTEM");
}

void barrier_stop() {
    servo_motor.write(0);        
}

void barrier_go() {
    servo_motor.write(90);         
}