Lab 5 Output: Piezo Speakers

Yuetian Wang. Professor Kimiko Ryokai. Tangible User Interface

Description

For this homework, I used the piezo buzzer to play a melody of Twinkle, Twinkle, Little Star, and then tried to use potentiometer to adjust the tune of this melody

code

/*
Connections For this application;
Use Freeduino-RichBoard made by www.EmbeddedMarket.com
1. Connect Digital Pin 9 to Buz pin in Section 9 on Freeduino Board
2. Connect USB Cable
*/

/* Melody
* (cleft) 2005 D. Cuartielles for K3
*
* This example uses a piezo speaker to play melodies. It sends
* a square wave of the appropriate frequency to the piezo, generating
* the corresponding tone.
*
* The calculation of the tones is made following the mathematical
* operation:
*
* timeHigh = period / 2 = 1 / (2 * toneFrequency)
*
* where the different tones are described as in the table:
*
* note frequency period timeHigh
* c 261 Hz 3830 1915
* d 294 Hz 3400 1700
* e 329 Hz 3038 1519
* f 349 Hz 2864 1432
* g 392 Hz 2550 1275
* a 440 Hz 2272 1136
* b 493 Hz 2028 1014
* C 523 Hz 1912 956
*
* http://www.arduino.cc/en/Tutorial/Melody
*/

int speakerPin = 8;
int photocellPin = 0;

int photocellVal = 0;
int toneVal;

int length = 15; // the number of notes

//twinkle twinkle little star
char notes[] = “ccggaag ffeeddc ggffeed ggffeed ccggaag ffeeddc “; // a space represents a rest
int beats[] = { 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 4 };
int tempo = 300;

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

void playNote(char note, int duration) {
char names[] = { ‘c’, ‘d’, ‘e’, ‘f’, ‘g’, ‘a’, ‘b’, ‘C’ };
int photocellVal = analogRead(photocellPin);
toneVal = photocellVal*2;
int tones[] = { 1915+toneVal, 1700+toneVal, 1519+toneVal, 1432+toneVal, 1275+toneVal, 1136+toneVal, 1014+toneVal, 956+toneVal };

// play the tone corresponding to the note name
for (int i = 0; i < 8; i++) {
if (names[i] == note) {
playTone(tones[i], duration);
}
}

Components Used

1-Arduino

1-Breadborad

1-potentiometer

1–10k ohm resistor

1-pizeo buzzer

Some Wires

Picture

Video