int TP1 = 12, EP1 = 11; // Trigger Pin 1, Echo Pin 1
int TP2 = 8, EP2 = 13; // Trigger Pin 2, Echo Pin 2

int pinBuzzer = 9;

int pinBuzzer2 = 10;

void setup() {

	// pines bat 1
	pinMode(EP1, INPUT);
	pinMode(TP1, OUTPUT);

	// pines bat 2
	pinMode(EP2, INPUT);
	pinMode(TP2, OUTPUT);

	pinMode(pinBuzzer, OUTPUT);
  pinMode(pinBuzzer2, OUTPUT);
}

void loop() {


	int max_freq = 4000; //maximum frequency

	int dist_freq = distance(TP1, EP1);
	int dist_tempo = distance(TP2, EP2);

	dist_freq = constrain(dist_freq, 1, 20);
	dist_tempo = constrain(dist_tempo, 1, 10); 

	dist_freq = map(dist_freq, 1, 20, 0, max_freq);
	dist_tempo = map(dist_tempo, 1, 10, 10, 100); 
  digitalWrite(pinBuzzer2, LOW);

	tone(pinBuzzer, dist_freq, dist_tempo);
	delay(dist_tempo);
}

long TP_init(int TP, int EP) {

	digitalWrite( TP , LOW);
	delayMicroseconds(2);
	digitalWrite( TP , HIGH);
	delayMicroseconds(10);
	digitalWrite( TP , LOW);
	long microseconds = pulseIn( EP , HIGH);
	return microseconds;
}

long distance(int TP, int EP) {

	long microseconds = TP_init(TP, EP);
	int distance1 = 	microseconds / 29 / 2;
                                                  
	return distance1;
}