E textiles & wearables II

Idea : create an instrument, Theremin.

The Theremin is an electronic instrument creating sound with no physical contact.

there is easier way to make sound with a sensor light and a piezo.

---

I follow this tutorial from John Nussey to start.

tools used :

• Arduino uno
• Breadboard
• Piezo buzzer
• Light sensor
• 2 resistors 0.22
• jump wires

schema :

The light sensor is connected to analog 0 on one side and 5V on the other.

the 2 resistors are connected between analog 0 and ground.

Circuit :

I did the Circuit with two resistors of 0.22 to have more or less the equivalent of a 4.7K resistor.

_

First, to understand the circuit and to know if a sound was going to be produce by the piezo, I connected everything on a breadboard.

I tried first with this piezo :

_

CODE

The sensor was capting different intensity of light and was producing sound from the piezo :

I tried with a Piezo buzzer instead. The sound is louder and has a different tonality depending on the code.

you can find the link HERE.

I tried with another code from the tutorial of Massimo Banzi and the sound has a different tonality.

cf HERE.

___

to be able to integrate this circuit into a fabric, I was thinking to use a ATtiny85 but unfortunately the Arduino “Tone” function is not supported on the ATtiny85 because it doesn't have the appropriate timers. I therefore needed to find a replacement way of generating simple tones.

Links

---

Code :

LED pin
const int ledPin= 13;
int sensorValue;
int sensorHigh;
int sensorLow; void setup() {
put your setup code here, to run once:
pinMode(ledPin, OUTPUT);
digitalWrite(ledPin, HIGH);

calibrate during the first five seconds
while (millis() < 5000) {
sensorValue = analogRead(A0); record the maximum sensor value
if (sensorValue > sensorHigh) {
sensorHigh = sensorValue;
}

record the minilum sensor value
if (sensorValue < sensorLow) {
sensorLow = sensorValue;
}

} signal the end of the calibration period
digitalWrite(ledPin, LOW);

}

void loop() {
read the input from A0
sensorValue = analogRead(A0); map the sensor values to a wide range of pitches
adjust the values bellow to conform the maximum and minimum
numbers you get from your sensor
int pitch =map(sensorValue, sensorLow,sensorHigh, 50, 4000);

play the tone
tone(8,pitch,20); wait for a moment
delay(10);

}