### Simple Audio Board

Another project I did for a friend of mine was called “Rick Roll”. It’s basically a board that just plays a Rick Astley song.   ```/*
This sketch uses the buzzer to play songs.
The Arduino's tone() command will play notes of a given frequency.
We'll provide a function that takes in note characters (a-g),
and returns the corresponding frequency from this table:

note 	frequency
c     262 Hz
d     294 Hz
e     330 Hz
f     349 Hz
g     392 Hz
a     440 Hz
b     494 Hz
C     523 Hz

*/

const int buzzerPin = 0;
const int ledPin = 1;

// We'll set up an array with the notes we want to play
// change these values to make different songs!

// Length must equal the total number of notes and spaces

const int songLength = 18;

// Notes is an array of text characters corresponding to the notes
// in your song. A space represents a rest (no tone)

char notes[] = "cdfda ag cdfdg gf "; // a space represents a rest

// Beats is an array values for each note and rest.
// A "1" represents a quarter-note, 2 a half-note, etc.
// Don't forget that the rests (spaces) need a length as well.

int beats[] = {1,1,1,1,1,1,4,4,2,1,1,1,1,1,1,4,4,2};

// The tempo is how fast to play the song.
// To make the song play faster, decrease this value.

int tempo = 150;

void setup()
{

pinMode(buzzerPin, OUTPUT);
pinMode(ledPin, OUTPUT);
}

void loop()
{
int i, duration;

digitalWrite(ledPin,HIGH);

for (i = 0; i < songLength; i++) // step through the song arrays
{
duration = beats[i] * tempo;  // length of note/rest in ms

if (notes[i] == ' ')          // is this a rest?
{
delay(duration);            // then pause for a moment
}
else                          // otherwise, play the note
{
tone(buzzerPin, frequency(notes[i]), duration);
delay(duration); // wait for tone to finish
}
delay(tempo/10);              // brief pause between notes
}

digitalWrite(ledPin,LOW);
// We only want to play the song once, so we'll pause forever:
while(true){}
// If you'd like your song to play over and over,
// remove the above statement
}

int frequency(char note)
{
// This function takes a note character (a-g), and returns the
// corresponding frequency in Hz for the tone() function.

int i;
const int numNotes = 8;  // number of notes we're storing

// The following arrays hold the note characters and their
// corresponding frequencies. The last "C" note is uppercase
// to separate it from the first lowercase "c". If you want to
// add more notes, you'll need to use unique characters.

// For the "char" (character) type, we put single characters
// in single quotes.

char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
int frequencies[] = {262, 294, 330, 349, 392, 440, 494, 523};

// Now we'll search through the letters in the array, and if
// we find it, we'll return the frequency for that note.

for (i = 0; i < numNotes; i++)  // Step through the notes
{
if (names[i] == note)         // Is this the one?
{
return(frequencies[i]);     // Yes! Return the frequency
}
}
return(0);  // We looked through everything and didn't find it,
// but we still need to return a value, so return 0.
}
```

SCHEMA: GET THE CODE:
RickRoll Code