Awesome Music Instrument (TBD)

/*
 Grove Buzzer

 The example uses a buzzer to play notes.
 
 The circuit:
 * Buzzer attached to Pin 39 (J14 plug on Grove Base BoosterPack)
 * Ultrasonic Ranger attached to Pin 24 (J6 plug on Grove Base BoosterPack)
*/

#include "TM1637.h" 
#include "Ultrasonic.h"
 
/* Macro Define */
#define BUZZER_PIN        39              /* sig pin of the Grove Buzzer */
#define ULTRASONIC_PIN    24              /* pin of the Ultrasonic Ranger */

int tempo = 300;
/* Global Variables */
Ultrasonic ultrasonic(ULTRASONIC_PIN);    /* Ultrasonic Ranger object */
int distance = 0;                         /* variable to store the distance to obstacles in front */

/* the setup() method runs once, when the sketch starts */
void setup()
{
  /* set buzzer pin as output */
  pinMode(BUZZER_PIN, OUTPUT);      

}

void loop()
{
    distance = ultrasonic.MeasureInCentimeters();   /* read the value from the sensor */  
    loopThruNotes(distance);
    delay(300);
}

void loopThruNotes(int distance) {
  if (distance < 10) {
    playTone(110, tempo);
  }
  else if (distance < 20) {
    playTone(123, tempo);
  }
  else if (distance < 30) {
    playTone(131, tempo);
  }
  else if (distance < 40) {
    playTone(147, tempo);
  }
  else if (distance < 50) {
    playTone(165, tempo);
  } 
  else if (distance < 60) {
    playTone(175, tempo);
  }
  else if (distance < 70) {
    playTone(195, tempo);
  }
  else if (distance < 80) {
    playTone(220, tempo);
  }
}

/* play tone */
void playTone(int tone, int duration) 
{
  for (long i = 0; i < duration * 1000L; i += tone * 2) 
  {
    digitalWrite(BUZZER_PIN, HIGH);
    delayMicroseconds(tone);
    digitalWrite(BUZZER_PIN, LOW);
    delayMicroseconds(tone);
  }
}