#define led 2
#define pir 10
#define bus 8

void setup() {
pinMode(pir, INPUT);
pinMode(led, OUTPUT);
pinMode(bus, OUTPUT);
Serial.begin(9600);
}

void loop() {
int valorpir = digitalRead(pir);

if (valorpir == HIGH) {
digitalWrite(led, HIGH);
Serial.println("¡Alto ahi muchachoo!");
delay(1500);} 

if (valorpir == HIGH){
for (int frec = 100; frec <= 1000; frec += 50) { 
tone(bus, frec);
delay(100);
}
for (int frec = 1000; frec >= 100; frec -= 50) { 
tone(bus, frec); 
delay(100); 
}
noTone(bus);
delay(1500); }

if (valorpir == LOW) {
digitalWrite(led, LOW);}

}