Page 177 - Hacking Roomba

158 Part II — Fun Things to Do

The core of RoombaTune in Listing 8-3 is the keyPressed() method. The switch(key){}
statement maps the computer keyboard to note number offset. Then if a note has been hit, the
note number offset is converted to the appropriate note number based on the current octave
setting and is played via the new playNote() command.
The RoombaTune sketch in Listing 8-3 is very minimal and not very Processing-like. Note
that it doesn’t do any of the normal things in setup() like set the frame rate or sketch size. It
also has a blank draw() method. RoombaTune turns the computer keyboard into a musical
keyboard to play Roomba. One simple and fun change you could do would be to draw lines or
circles based on a note number. RoombaTune then becomes a music-activated screensaver.
To add even more musical control, you can add more functions to the unused keys of the com-
puter keyboard to add turning on and off the vacuum motors, drive motors, and LEDs.

Listing 8-3: RoombaTune Live Instrument Processing Sketch

String roombacommPort = “/dev/cu.KeySerial1”; // or COM3, etc.
void setup() {
if( !roombacomm.connect(roombacommPort) ) {
println(“couldn’t connect. goodbye.”); System.exit(1);
}
println(“Roomba startup”);
roombacomm.startup();
roombacomm.control();
roombacomm.pause(50);
}
void draw() {
}
void keyPressed() {
int note=-1; // -1 means no note yet
switch( key ) {
// pseudo-keyboard to play notes on
case ‘a’: note = 0; break;
case ‘w’: note = 1; break;
case ‘s’: note = 2; break;
case ‘e’: note = 3; break;
case ‘d’: note = 4; break;
case ‘f’: note = 5; break;
case ‘t’: note = 6; break;
case ‘g’: note = 7; break;
case ‘y’: note = 8; break;
case ‘h’: note = 9; break;
case ‘u’: note =10; break;
case ‘j’: note =11; break;
case ‘k’: note =12; break;
case ‘o’: note =13; break;
case ‘l’: note =14; break;
case ‘z’: octave--; break; // change octaves
case ‘x’: octave++; break; // change octaves
}
// we actually hit a note key