Lab 5: Star Wars Song Selector

Submitted by MarieSpliid on Tue, 03/05/2013 - 16:52

Description

In this assignment I have created The Song Selector, this version feat. Star Wars songs. The Selector is represented as a meter with a light saber as a pin. The  direction of the light saber decides which song to be played. If pointed at Darth Vader, The Imperial March plays, and if pointed at Luke Skywalker, The Star Wars Theme plays.

The Song Selcector could be used for any other set of songs with accompanying visual representations on the meter.

I was inspired by this code piece, which is an application for using the Arduino and Piezo Buzzer to compose and play a tune.

I composed and new tune, Melody 1 (The Imperial March), and kept one of the already composed tunes, Melody 2 (Star Wars Theme).

Components

• Arduino Uno
• Potentiometer
• Piezo buzzer
• Resistor (10 ohm)
• Paper
• Crayons
• Tape
• Glue

Challenges

There is still a major issues in the code, that I haven't been able to solve: The first song chosen (the value read as soon as the Arduino board gets plugged in), plays to an end, before the next song can begin. I would like the potentiometer value to be continuously read, so that the user can change songs whenever desired.

I have had trouble solving this, as the initial code I am using, declares the main part of the function that plays the array of tones is not in the loop, but in a function declared in the viod playTone() before the loop. I have not been able to figure out how to rearrange the code pieces in a way that allows me to break out of the playTone() during a song.

Code

/* Star Wars Song Selector
* -----------
*
* Program to choose between two melodies by using a potentiometer and a piezo buzzer.
*/

// TONES //
// Defining the relationship between note, period & frequency.

// period is in microsecond so P = 1/f * (1E6)

#define  c3    7634
#define  d3    6803
#define  e3    6061
#define  f3    5714
#define  g3    5102
#define  a3    4545
#define  b3    4049
#define  c4    3816    // 261 Hz
#define  d4    3401    // 294 Hz
#define  e4    3030    // 329 Hz
#define  f4    2865    // 349 Hz
#define  g4    2551    // 392 Hz
#define  a4    2272    // 440 Hz
#define  a4s   2146
#define  b4    2028    // 493 Hz
#define  c5    1912    // 523 Hz
#define  d5    1706
#define  d5s   1608
#define  e5    1517    // 659 Hz
#define  f5    1433    // 698 Hz
#define  g5    1276
#define  a5    1136
#define  a5s   1073
#define  b5    1012
#define  c6    955

#define  R     0      // Define a special note, 'R', to represent a rest

// SETUP //

int speakerOut = 7;    // Set up speaker on digital pin 7
int potPin = A0;      // Set up potentiometer on analogue pin 0.

void setup() {
pinMode(speakerOut, OUTPUT);
Serial.begin(9600); // Set serial out if we want debugging
}
//}

// MELODIES and TIMING //
//  melody[] is an array of notes, accompanied by beats[],
//  which sets each note's relative length (higher #, longer note)

// Melody 1: Star Wars Imperial March
int melody1[] = {  a4, R,  a4, R,  a4, R,  f4, R, c5, R,  a4, R,  f4, R, c5, R, a4, R,  e5, R,  e5, R,  e5, R,  f5, R, c5, R,  g5, R,  f5, R,  c5, R, a4, R};
int beats1[]  = {  50, 20, 50, 20, 50, 20, 40, 5, 20, 5,  60, 10, 40, 5, 20, 5, 60, 80, 50, 20, 50, 20, 50, 20, 40, 5, 20, 5,  60, 10, 40, 5,  20, 5, 60, 40};

// Melody 2: Star Wars Theme
int melody2[] = {  f4,  f4, f4,  a4s,   f5,  d5s,  d5,  c5, a5s, f5, d5s,  d5,  c5, a5s, f5, d5s, d5, d5s,   c5};
int beats2[]  = {  21,  21, 21,  128,  128,   21,  21,  21, 128, 64,  21,  21,  21, 128, 64,  21, 21,  21, 128 };

int MAX_COUNT = sizeof(melody1) / 2; // Melody length, for looping.

long tempo = 10000; // Set overall tempo

int pause = 1000; // Set length of pause between notes

int rest_count = 50; // Loop variable to increase Rest length (BLETCHEROUS HACK; See NOTES)

// Initialize core variables
int toneM = 0;
int beat = 0;
long duration  = 0;
int potVal = 0;

// PLAY TONE  //
// Pulse the speaker to play a tone for a particular duration
void playTone() {
long elapsed_time = 0;
if (toneM > 0) { // if this isn't a Rest beat, while the tone has
//  played less long than 'duration', pulse speaker HIGH and LOW
while (elapsed_time < duration) {

digitalWrite(speakerOut,HIGH);
delayMicroseconds(toneM / 2);

// DOWN
digitalWrite(speakerOut, LOW);
delayMicroseconds(toneM / 2);

// Keep track of how long we pulsed
elapsed_time += (toneM);
}
}
else { // Rest beat; loop times delay
for (int j = 0; j < rest_count; j++) { // See NOTE on rest_count
delayMicroseconds(duration);
}
}
}

// LOOP //
void loop() {
Serial.println(potVal); // Print potVal in serial monitor

if (potVal < 511) { // If potVal is less than 511, play Melody1...

// Set up a counter to pull from melody1[] and beats1[]
for (int i=0; i<MAX_COUNT; i++) {
toneM = melody1[i];
beat = beats1[i];

duration = beat * tempo; // Set up timing

playTone(); // A pause between notes
delayMicroseconds(pause);
}
}
else    // ... else play Melody2
for (int i=0; i<MAX_COUNT; i++) {
toneM = melody2[i];
beat = beats2[i];

duration = beat * tempo; // Set up timing

playTone(); // A pause between notes
delayMicroseconds(pause);
}
}

/*
* NOTES
* The program purports to hold a tone for 'duration' microseconds.
*  Lies lies lies! It holds for at least 'duration' microseconds, _plus_
*  any overhead created by incremeting elapsed_time (could be in excess of
*  3K microseconds) _plus_ overhead of looping and two digitalWrites()
*
* As a result, a tone of 'duration' plays much more slowly than a rest
*  of 'duration.' rest_count creates a loop variable to bring 'rest' beats
*  in line with 'tone' beats of the same length.
*
* rest_count will be affected by chip architecture and speed, as well as
*  overhead from any program mods. Past behavior is no guarantee of future
*  performance. Your mileage may vary. Light fuse and get away.
*/

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