Saturday, 15 August 2015

Playing the Spanish Flea tune with an Arduino and a piezo buzzer

I wanted to make the Arduino play a tune so I purchased a piezo buzzer online. I ordered it from AliExpress and it was only a couple dollars including delivery.
Figure 1: Piezo buzzer
Connecting the buzzer to the Arduino is easy. I simply connected the positive wire from the buzzer to a pin which supports Pulse Width Modulation (PWM). On my Arduino Mega 2560 I used pin 3. Then I connected the negative wire from the buzzer to a resistor and the other end of the resistor to ground. I used a 220 ohm resistor. The larger the resistor the quieter the buzzer will sound.
Figure 2: Arduino Mega 2560 and piezo buzzer wiring diagram
Figure 3: Photo of Arduino Mega 2560 and piezo buzzer setup
Playing a tone on the Arduino is done using the Tone function. The official documentation for the tone function can be found here. In my code I used the version of the function which takes three parameters. These are the pin to output the tone on, the frequency of the tone and the duration of the tone. For example if you want to play a frequency of 500Hz on pin 3 for one second you will write code as tone(3, 500, 1000)

I based my code on the example melody code which comes with the Arduino software. The example code contains definitions for each note and the frequency they correspond with. This makes the code much easier to read and debug then if we were to refer to the notes as their frequencies.

As a song is comprised of many notes and the duration of each note is important I created an array for the notes and an array for each notes duration. I called these arrays note and noteDuration. I also created a variable for the beats per minute called bpm to allow me to control the tempo.

Next I setup pin 3 on the Arduino to be an output. In the main loop I call a function called playTune which contains all the code to play the song.

In the playTune function I first calculate the duration of each note. This is done by dividing 60000 (number of milliseconds in a minute) but the number of beats per minute as specified in the bpm variable. After this is calculated I then iterate through the arrays and for each element I call the tone function specifying the note to play and the duration of the note.

As the Tone function is non blocking I then sleep for the duration of the note plus a small delay (I use 10 milliseconds as it sounds better with a small delay) before doing the same with the next array elements. The basic logic of the code is shown in Figure 4 below.

//Plays the tune
void playTune()
{
  //Determine size of array
  int arraySize = sizeof(note) / sizeof(int);

  //Determine duration of a quarter note
  int quarterNoteDuration = 60000 / bpm;

  //Iterate through note array
  for (int counter = 0; counter < arraySize; counter++)
  {
    if (note[counter] != 0) 
    {
      //Play the note      
      tone(buzzerPin, note[counter], quarterNoteDuration * noteDuration[counter]);
    }

      //Wait for the note to finish before playing next note
      delay(quarterNoteDuration * noteDuration[counter] + 10);
  }
}
Figure 4: Function to play the tune

I found the trickiest and most time consuming part to be transcribing the song from sheet music into the note and duration arrays.

To begin transcribing the first thing you need is the music. To keep things simple I looked for sheet music which only had a single note being played at any one time. I was able to find several versions of the Spanish Flea song on the MuseScore website including one which satisfied my requirements.

I then went about the arduous task of populating the note and duration arrays. I assigned quarter notes a duration value of 1 as their duration equals one beat. Other notes are assigned a fractional value relative to the duration of a quarter note.

A complete code listing including the populated arrays is in Figure 5 below.

//Playing the Spanish Flea with Arduino and Piezo buzzer 
//Created by Blax
//www.blaxlab.com

#define NOTE_B0  31
#define NOTE_C1  33
#define NOTE_CS1 35
#define NOTE_D1  37
#define NOTE_DS1 39
#define NOTE_E1  41
#define NOTE_F1  44
#define NOTE_FS1 46
#define NOTE_G1  49
#define NOTE_GS1 52
#define NOTE_A1  55
#define NOTE_AS1 58
#define NOTE_B1  62
#define NOTE_C2  65
#define NOTE_CS2 69
#define NOTE_D2  73
#define NOTE_DS2 78
#define NOTE_E2  82
#define NOTE_F2  87
#define NOTE_FS2 93
#define NOTE_G2  98
#define NOTE_GS2 104
#define NOTE_A2  110
#define NOTE_AS2 117
#define NOTE_B2  123
#define NOTE_C3  131
#define NOTE_CS3 139
#define NOTE_D3  147
#define NOTE_DS3 156
#define NOTE_E3  165
#define NOTE_F3  175
#define NOTE_FS3 185
#define NOTE_G3  196
#define NOTE_GS3 208
#define NOTE_A3  220
#define NOTE_AS3 233
#define NOTE_B3  247
#define NOTE_C4  262
#define NOTE_CS4 277
#define NOTE_D4  294
#define NOTE_DS4 311
#define NOTE_E4  330
#define NOTE_F4  349
#define NOTE_FS4 370
#define NOTE_G4  392
#define NOTE_GS4 415
#define NOTE_A4  440
#define NOTE_AS4 466
#define NOTE_B4  494
#define NOTE_C5  523
#define NOTE_CS5 554
#define NOTE_D5  587
#define NOTE_DS5 622
#define NOTE_E5  659
#define NOTE_F5  698
#define NOTE_FS5 740
#define NOTE_G5  784
#define NOTE_GS5 831
#define NOTE_A5  880
#define NOTE_AS5 932
#define NOTE_B5  988
#define NOTE_C6  1047
#define NOTE_CS6 1109
#define NOTE_D6  1175
#define NOTE_DS6 1245
#define NOTE_E6  1319
#define NOTE_F6  1397
#define NOTE_FS6 1480
#define NOTE_G6  1568
#define NOTE_GS6 1661
#define NOTE_A6  1760
#define NOTE_AS6 1865
#define NOTE_B6  1976
#define NOTE_C7  2093
#define NOTE_CS7 2217
#define NOTE_D7  2349
#define NOTE_DS7 2489
#define NOTE_E7  2637
#define NOTE_F7  2794
#define NOTE_FS7 2960
#define NOTE_G7  3136
#define NOTE_GS7 3322
#define NOTE_A7  3520
#define NOTE_AS7 3729
#define NOTE_B7  3951
#define NOTE_C8  4186
#define NOTE_CS8 4435
#define NOTE_D8  4699
#define NOTE_DS8 4978

int note[] = {
  NOTE_AS5, NOTE_F5, NOTE_F5, NOTE_F4, NOTE_F5, NOTE_F5, 
  NOTE_AS5, NOTE_F5, NOTE_F4, NOTE_F4, NOTE_F5, 
  NOTE_AS5, NOTE_F5, NOTE_F5, NOTE_F4, NOTE_F5, NOTE_F5, 
  NOTE_AS5, 0, 0, NOTE_D5, NOTE_DS5, NOTE_E5,
  NOTE_F5,NOTE_D6, NOTE_D6, NOTE_C6, NOTE_B6, 
  0, 0, NOTE_G5, NOTE_FS5, NOTE_F5, 
  NOTE_E5, NOTE_C6, NOTE_C6, NOTE_AS6, NOTE_A6, 
  0, 0, NOTE_F5, NOTE_E5, NOTE_DS5, 
  NOTE_D5, NOTE_F5, NOTE_AS6, NOTE_G5, NOTE_AS6, NOTE_C6, 
  NOTE_F5, NOTE_GS5, NOTE_CS6,NOTE_AS6, NOTE_D6, NOTE_DS6, 
  NOTE_F6, 
  0, NOTE_F6, NOTE_F6, NOTE_G6, NOTE_F6, NOTE_CS6, NOTE_C6, 
  NOTE_AS6, NOTE_D6, NOTE_D6, NOTE_C6, NOTE_B6, 
  0, 0, NOTE_G5, NOTE_FS5,NOTE_F5, 
  NOTE_E5, NOTE_C6, NOTE_C6, NOTE_B6, NOTE_A6, 
  0, 0, 0, NOTE_F5, NOTE_E5, NOTE_E5, 
  NOTE_D5, NOTE_E5, NOTE_AS5,NOTE_G5, NOTE_AS6, NOTE_C6, 
  NOTE_F5, NOTE_GS5, NOTE_CS6, NOTE_AS6, NOTE_D6, NOTE_DS6, 
  NOTE_F6, 
  0, NOTE_F6, NOTE_F6, NOTE_G6, NOTE_F6, NOTE_CS6, NOTE_C6,
  NOTE_AS5, NOTE_F5, NOTE_F5, NOTE_F4, NOTE_F5, NOTE_F5, 
  NOTE_AS5, NOTE_F5, NOTE_F4, NOTE_F4, NOTE_F5, 
  NOTE_AS5,NOTE_F5, NOTE_F5, NOTE_F4, NOTE_F5, NOTE_F5, 
  NOTE_AS5, NOTE_AS6, NOTE_C6, NOTE_D6, 
  NOTE_DS6, 0, 0, NOTE_DS6, NOTE_F6, NOTE_DS6,
  NOTE_G6, NOTE_F6, NOTE_DS6, NOTE_CS6, NOTE_C6, NOTE_AS6, 
  NOTE_GS5, NOTE_A6, NOTE_A6, NOTE_AS6, NOTE_B6, NOTE_C6, 
  NOTE_GS4, NOTE_B5, NOTE_C5, NOTE_AS5, NOTE_A5, 0, 
  NOTE_CS6, 0, 0, NOTE_D6, NOTE_DS6, NOTE_D6, 
  NOTE_F6, NOTE_DS6, NOTE_CS6, NOTE_B6, NOTE_AS6, NOTE_A6, NOTE_FS5, 
  NOTE_G5, NOTE_G5, NOTE_GS5, NOTE_AS5, 0, 
  NOTE_A6, NOTE_AS6, NOTE_C6
};

float noteDuration[] = {
  1, 0.5, 0.5, 1, 0.5, 0.5, 
  1, 0.5, 1, 0.5, 1, 
  1, 0.5, 0.5, 1, 0.5, 0.5, 
  1, 1, 0.5, 0.5, 0.5, 0.5, 
  1, 1, 0.5, 1, 1.5, 
  1, 0.5, 0.5, 0.5, 0.5, 
  1, 1, 0.5, 1, 1.5, 
  1, 0.5, 0.5, 0.5, 0.5, 
  0.5, 0.5, 0.5, 1, 0.5, 1, 
  0.5, 0.5, 0.5, 1, 0.5, 1, 
  4, 
  1, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 
  1, 1, 0.5, 1, 1, 
  1, 1, 0.5, 0.5, 0.5, 
  1, 1, 0.5, 1, 1, 
  0.5, 1, 0.5, 0.5, 0.5, 0.5, 
  0.5, 0.5, 0.5, 1, 0.5, 1, 
  0.5, 0.5, 0.5, 1, 0.5, 1, 
  4, 
  0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 
  1, 0.5, 0.5, 1, 0.5, 0.5, 
  1, 0.5, 1, 0.5, 1, 
  1, 0.5, 0.5, 1, 0.5, 0.5, 
  1, 1, 1, 1, 
  1, 1, 0.5, 0.5, 0.5, 0.5, 
  0.5, 1, 1, 0.5, 0.5, 0.5, 
  1, 0.5, 0.5, 0.5, 1, 1.5, 
  0.5, 0.5, 0.5, 0.5, 1, 0.5, 
  1, 1, 0.5, 0.5, 0.5, 0.5, 
  0.5, 1, 1, 0.5, 0.5, 0.5, 
  1, 0.5, 0.5, 0.5, 1, 0.5, 
  0.5, 1, 1
};

#define buzzerPin 3

#define bpm 160

void setup() 
{
  pinMode(3, OUTPUT);  
}

void loop() 
{
  playTune();
}

//Plays the tune
void playTune()
{
  //Determine size of array
  int arraySize = sizeof(note) / sizeof(int);

  //Determine duration of a quarter note
  int quarterNoteDuration = 60000 / bpm;

  //Iterate through note array
  for (int counter = 0; counter < arraySize; counter++)
  {
    if (note[counter] != 0) 
    {
      //Play the note      
      tone(buzzerPin, note[counter], quarterNoteDuration * noteDuration[counter]);
    }

      //Wait for the note to finish before playing next note
      delay(quarterNoteDuration * noteDuration[counter] + 10);
  }
}
Figure 5: Complete code to play Spanish Flea tune

All that was left was to upload the program to the Arduino and power it up. A video demonstrating the completed project is below.

Figure 6: Video of Arduino playing Spanish Flea tune

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