int pino_trig = 18;
int pino_echo = 19;
int LED1 = 21;
int LED2 = 22;
int LED3 = 23;
int buzzer = 15;


void setup() {
Serial.begin(9600);
pinMode(pino_trig, OUTPUT);
pinMode(pino_echo, INPUT);
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LED3, OUTPUT);
pinMode(buzzer, OUTPUT);
}
void loop() {
digitalWrite(pino_trig, LOW);
delayMicroseconds(2);
digitalWrite(pino_trig, HIGH);
delayMicroseconds(2);
digitalWrite(pino_trig, LOW);
long duracao = pulseIn(pino_echo, HIGH);
int distancia = (duracao * 0.0343) /2;
Serial.print(distancia);
Serial.print(" cm");
digitalWrite(LED1, LOW);
digitalWrite(LED2, LOW);
digitalWrite(LED3, LOW);
noTone(buzzer);

if (distancia < 5){
    digitalWrite(LED1, HIGH);
tone(buzzer, 262);
}
else if (distancia < 15){
    digitalWrite(LED2, HIGH);
tone(buzzer, 262, 100);
}
else if (distancia < 30){
    digitalWrite(LED1, HIGH);
 tone(buzzer, 262, 100);
 delay(00);
}
delay(300);
}