// MCU BASIC: https://www.basic4mcu.com
// DateTime : 2018-10-15 오후 5:50:18
// by Ok-Hyun Park
//
#define TRIG  2  // 초음파 트리거 2번
#define ECHO  3  // 초음파 에코 3번
#define RED   11 // RGB 핀
#define GREEN 10 // RGB 핀
#define BLUE  9  // RGB 핀
//
int button=5;
int buttonState=0,run=0;
//
void setup(){
  pinMode(TRIG,OUTPUT); pinMode(ECHO,INPUT); //초음파
  pinMode(button,INPUT_PULLUP);
  analogWrite(RED,255); analogWrite(GREEN,255); analogWrite(BLUE,255);
  Serial.begin(9600);
}
//
void loop(){
  if(digitalRead(button)==LOW){
    if(buttonState==0){ buttonState=1; run^=1; delay(50); }
  }
  else{
    if(buttonState){ buttonState=0; delay(50); }
  }
  //
  if(run){
    digitalWrite(TRIG,HIGH); delayMicroseconds(10); digitalWrite(TRIG,LOW);
    long distance=pulseIn(ECHO,HIGH)/58.2;
    Serial.print(distance); Serial.println("cm");
    //
    analogWrite(RED,255); analogWrite(GREEN,255); analogWrite(BLUE,255);
    if     (distance<20){ analogWrite(RED,0); }
    else if(distance<40){ analogWrite(GREEN,0); }
    else if(distance<60){ analogWrite(BLUE,0); }
  }
}