int LEDMERAH=10;
int LEDKUNING=9;
int LEDHIJAU=8;
int BUZZER=13;
int value;
const int TRIGPIN=2;
const int ECHOPIN=1;
long timer;
int jarak;

void setup()
{
Serial.begin(7000);
pinMode(LEDMERAH, OUTPUT);
pinMode(LEDKUNING, OUTPUT);
pinMode(LEDHIJAU, OUTPUT);
pinMode(BUZZER, OUTPUT);
pinMode(ECHOPIN, INPUT);
}

void loop()
{
  digitalWrite(TRIGPIN, LOW);
  delayMicroseconds(10);
  digitalWrite(TRIGPIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGPIN, LOW);

  timer=pulseIn(ECHOPIN, HIGH);
  jarak=timer/58;
  delay(1000);

  Serial.print("jarak=");
  Serial.print(jarak);
  Serial.print("cm");
  Serial.println();

  value=analogRead(TRIGPIN);
  tone(BUZZER, value);
  if(jarak > 50){
    digitalWrite(LEDMERAH, HIGH);
}
else{
  digitalWrite(LEDMERAH, LOW);
  }

  if(jarak > 100){
    digitalWrite(LEDKUNING, HIGH);
}
else{
  digitalWrite(LEDKUNING, LOW);
  }

  if(jarak > 200){
digitalWrite(LEDHIJAU, HIGH);
}
else{
digitalWrite(LEDHIJAU, LOW);
  }

}