If you like that effect, you might also like this — the Theremin
How about an arduino theremin?
The capacitive sensing code was not written by me, but altered by me. (The
capacitive sensing program is interesting in its self). The origional code
was from here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1171076259
I haven't tried building this theremin yet, but the code is here. Even if it
doesn't work, it could be altered for other purposes...
// Fun with capacitive sensing and some machine code - for the Arduino (or Wiring Boards).
// Note that the machine code is based on Arduino Board and will probably require some changes for Wiring Board
// This works with a high value (1-10M) resistor between an output pin and an input pin.
// When the output pin changes it changes the state of the input pin in a time constant determined by R * C
// where R is the resistor and C is the capacitance of the pin plus any capacitance present at the sensor.
// It is possible when using this setup to see some variation in capacitance when one's hand is 3 to 4 inches from the sensors
// Try experimenting with larger sensors. Lower values of R will probably yield higher reliability.
// Use 1 M resistor (or less maybe) for absolute touch to activate.
// With a 10 M resistor the sensor will start to respond 1-2 inches away
// Setup
// Connect a 10M resistor between pins 8 and 9 on the Arduino Board
// Connect a small piece of alluminum or copper foil to a short wire and also connect it to pin 9
// Machine code and Port stuff from a forum post by ARP http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1169088394/0#0
int frequency;
const int tonePin = 2;
int i;
unsigned int x, y;
float accum, fout, fval = .07; // these are variables for a simple low-pass (smoothing) filter - fval of 1 = no filter - .001 = max filter
void setup() {
pinMode(ledPin, OUTPUT);
Serial.begin(9600);
pinMode(tonePin, OUTPUT); // output pin
pinMode(8, OUTPUT); // output pin
pinMode(9, INPUT); // input pin
pinMode(10, OUTPUT); // guard pin
digitalWrite(10, LOW); //could also be HIGH - don't use this pin for changing output though
}
void loop() {
y = 0; // clear out variables
x = 0;
for (i=0; i < 4 ; i++ ){ // do it four times to build up an average - not really neccessary but takes out some jitter
digitalWrite(8, HIGH);
while (digitalRead(9) != 1)
x++;
}
delay(1);
// HIGH-to-LOW transition
digitalWrite(8, LOW);
while(digitalRead(9) != 0 ){ // same as above port manipulation - only 20 times slower!
y++;
}
delay(1);
fout = (fval * (float)x) + ((1-fval) * accum); // Easy smoothing filter "fval" determines amount of new data in fout
accum = fout;
Serial.println( (long)fout, DEC);
frequuency = map((long)fout, 0 1000, 100, 700); //change values for the desired frequency (output) and min/max range (input)
tone(tonePin, frequency);
delay(1);
noTone(tonePin);
}