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E textiles & wearables II

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==== Theme : Sound and electronics ====

**__Idea : create an instrument, Theremin.__ **

The [[https://en.wikipedia.org/wiki/Theremin|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.

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I follow this [[http://www.dummies.com/computers/arduino/how-to-make-an-instrument-with-the-arduino/|tutorial]] from John Nussey to start.

tools used :

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

== _ ==

== step 1 : ==

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.

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:381399.image1.jpg?nolink&400x400|381399.image1.jpg}}

Circuit :

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:381398.image0.jpg?nolink&400x559|381398.image0.jpg}}

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

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:schema_lightsensor_2resistors.png?nolink&400x308}}

_

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 :

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:piezo_sticking_details.png?nolink&200x193}}

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CODE

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:capture_d_ecran_2017-11-30_a_14.46.06.png?nolink&500x563}}

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

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:capture_d_ecran_2017-11-30_a_15.03.00.png?nolink&1000x578}}

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 [[https://youtu.be/iWZ6pqbe-ZQ|HERE]].

{{:fabricademy2017:students:pauline_bianchi:electronics_ii:img_5040.jpg?nolink&500x374|img_5040.jpg}}

I tried with another code from the tutorial of [[https://youtu.be/WLLiiyWKxs8|Massimo Banzi]] and the sound has a different tonality.

cf [[https://youtu.be/Db80nwXNTiE|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.

[[https://drive.google.com/open?id=1oiuKLGcyv26BYSCxaXGjiJSuigdh3D4G|Links]]

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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);

}