Post date: Jul 17, 2010 2:29:6 AM
This circuit uses four push buttons connected to pins 4-7 on the Arduino to control sound in Processing. For each button pressed, a different drum sound is played in Processing. For example: when the button connected to pin 4 is pressed, a cowbell sound is played. The sounds can also be played by pressing keys k, j, h, and g.
Arduino code:
int switchPin1 = 4; // declares variables
int switchPin2 = 5;
int switchPin3 = 6;
int switchPin4 = 7;
void setup() {
Serial.begin(9600); // begin serial communication at 9600 bps
pinMode(switchPin1, INPUT); // set switchPins to input
pinMode(switchPin2, INPUT);
pinMode(switchPin3, INPUT);
pinMode(switchPin4, INPUT);
}
void loop() {
if(digitalRead(switchPin1) == HIGH) { // if button is pressed
Serial.print(1, DEC); // print this number
delay(100); // and delay for 100 milliseconds
}
else if(digitalRead(switchPin2) == HIGH) {
Serial.print(2, DEC);
delay(100);
}
else if(digitalRead(switchPin3) == HIGH) {
Serial.print(3, DEC);
delay(100);
}
else if(digitalRead(switchPin4) == HIGH) {
Serial.print(4, DEC);
delay(100);
}
}
Processing code:
import processing.serial.*; // import libraries
import ddf.minim.*;
Minim minim; // declare variables
AudioSample cowbell;
AudioSample bass;
AudioSample kick;
AudioSample snare;
Serial myPort;
void setup()
{
// sets screen size
size(512, 200, P2D);
// always start Minim before you do anything with it
minim = new Minim(this);
// load file from the data folder, with a 512 sample buffer
cowbell = minim.loadSample("Cowbell.mp3");
bass = minim.loadSample("Bass.wav");
kick = minim.loadSample("Kick.wav");
snare = minim.loadSample("Snare.wav");
// sets port to read from
String portName = Serial.list()[0];
myPort = new Serial(this, Serial.list()[0], 9600);
}
void draw()
{
int val = 0; // resets value every time draw is run
background(0); // sets background color
stroke(255); // sets stroke color
// use the mix buffer to draw the waveforms.
// because these are MONO files, we could have used the left or right buffers and got the same data
for (int i = 0; i < cowbell.bufferSize() - 1; i++)
{
line(i, 100 - cowbell.left.get(i)*50, i+1, 100 - cowbell.left.get(i+1)*50);
}
for (int u = 0; u < bass.bufferSize() - 1; u++)
{
line(u, 100 - bass.left.get(u)*50, u+1, 100 - bass.left.get(u+1)*50);
}
for (int y = 0; y < kick.bufferSize() - 1; y++)
{
line(y, 100 - kick.left.get(y)*50, y+1, 100 - kick.left.get(y+1)*50);
}
for (int t = 0; t < snare.bufferSize() - 1; t++)
{
line(t, 100 - snare.left.get(t)*50, t+1, 100 - snare.left.get(t+1)*50);
}
if (myPort.available() > 0) { // if there is data available to read,
val = myPort.read(); // read it and store it in val
println(val); // print the value of val
}
if (val == 49 ) cowbell.trigger(); // if val is this, play the sound
if (val == 50 ) bass.trigger();
if (val == 51 ) kick.trigger();
if (val == 52 ) snare.trigger();
}
void keyPressed()
{
if ( key == 'k' ) cowbell.trigger(); // if this key is pressed, play this sound
if ( key == 'j' ) bass.trigger();
if ( key == 'h' ) kick.trigger();
if ( key == 'g' ) snare.trigger();
}
void stop()
{
// always close Minim audio classes when you are done with them
cowbell.close();
bass.close();
kick.close();
snare.close();
minim.stop();
super.stop();
}
This one took me a while to figure out. It took me a couple tries to figure out where exactly to save the sound clips so that they could be read in the program, and then when i got that worked out the sound would repeat until another button was pressed, and then that sound would repeat. I solved that by resetting val every time the void draw function was run. I still have no idea where the values change from 1-4 to 49-52, but I got the program working and I didn't want to mess it up. A Fritzing picture of my circuit is attached.