#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C LCD(0x27,16,2);
#define Red 4
#define Green 5
#define Blue 6
#define trig 2
#define echo 3

void setup(){
  pinMode(Red, OUTPUT);
  pinMode(Green, OUTPUT);
  pinMode(Blue, OUTPUT);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  LCD.init();
  LCD.print("Patiwat");
}
void red(int msec){
  digitalWrite(Red, HIGH);
  digitalWrite(Green, LOW);
  digitalWrite(Blue, LOW);
  delay(msec);
}
void green(int msec){
  digitalWrite(Red, LOW);
  digitalWrite(Green, HIGH);
  digitalWrite(Blue, LOW);
  delay(msec);
}
void blue(int msec){
  digitalWrite(Red, LOW);
  digitalWrite(Green, LOW);
  digitalWrite(Blue, HIGH);
  delay(msec);
}
void yellow(int msec){
  digitalWrite(Red, HIGH);
  digitalWrite(Green, HIGH);
  digitalWrite(Blue, LOW);
  delay(msec);
}
void cyan(int msec){
  digitalWrite(Red, LOW);
  digitalWrite(Green, HIGH);
  digitalWrite(Blue, HIGH);
  delay(msec);
}
void purple(int msec){
  digitalWrite(Red, HIGH);
  digitalWrite(Green, LOW);
  digitalWrite(Blue, HIGH);
  delay(msec);
}
void white(int msec){
  digitalWrite(Red, HIGH);
  digitalWrite(Green, HIGH);
  digitalWrite(Blue, HIGH);
  delay(msec);
}
void black(int msec){
  digitalWrite(Red, LOW);
  digitalWrite(Green, LOW);
  digitalWrite(Blue, LOW);
  delay(msec);
}
void distance(){
  digitalWrite(trig,HIGH);
  delay(100);
  digitalWrite(trig, LOW);
  int cm = (pulseIn(echo,HIGH))/58;
  LCD.setCursor(0,1);
  LCD.print("Distance:");
  LCD.print(cm);
  LCD.print(" cm  ");
  if(cm<=50){
//ให้ไฟแดงกระพริบและมีเสียงเตือนถี่ๆ
    black(500);
  }else if(cm<=100){
//ให้ไฟเหลืองกระพริบและมีเสียงเตือน
    black(500);
  }else{
//ไฟเขียวติด + เสียงเมโลดี้
    green(1000);
    tone(7,300,500);
    tone(7,400,500);
  }
}
void loop(){
  distance();
}