Theremin

Curious about building a Theremin instrument? Checkout this tutorial!

IntermediateFull instructions provided1,988

Things used in this project

Hardware components

Punch Through LightBlue Bean

Software apps and online services

Punch Through Bean Loader

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Pliers

Story

Introduction

This example project uses a light sensor and a piezo speaker to generate a changing tone based on the amount of light sensed. More light causes the Bean to produce a higher-pitch tone and vice versa.

Software

Node-RED
Bean Loader

Hardware

LightBlue Bean
Windows or OS X computer

Solder the Light Sensor and Piezo Buzzer

Step 1: Solder the Light Sensor

You will need to solder the Light Sensor before starting this guide. Follow the Light Sensor guide first.

Step 2: Gather Components

Find these parts in your Maker Kit:

1K Ohm Resistor
1 Piezo Speaker

Step 3: Place Components and Bend Leads

Place the components as seen below.You’ll need to bend one leg of the Piezo Buzzer so it can reach the pin labeled ‘2’. Trim it to size.Bend the pins as seen below.

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Step 4: Solder Components and Clip Leads

Solder all the pins. The end result is shown below.The top should look like this.

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Step 5: Program the Bean

Now all you need to do is load up the sketch below, and program your Bean! Once programmed, your Bean should play a tone that changes frequency based on how much light is detected!

How the Sketch Work

*Line 1-2: we define a macro. The compiler can then substitute the token string for each occurrence in the source file.

*Line 4: is the setup function. This function is executed only once during the duration of the program.

*Line 5-8: we initialize the serial communication. We set GPIO pin 0 and 2 and output. We turn pin 0 off ('low')

*Line 11: is the loop function. This function is executed multiple times.

*Line 12-15: We turn pin 0 on and read the data from A1 pin. We initialize r, g, b as variables.

*Line 16-31: we check the conditions of the sensorValues, BLEVEL, and MINLEVEL, and reassign 'g' and 'b' accordingly.

*Line 32: we set the Bean's LED.

*Line 33: we play the tones.

Troubleshooting

Having trouble with this guide? Reach out to BeanTalk to get directed feedback from our developers and community!

Code

#define BLEVEL 255
#define MINLEVEL 50

void setup() {
  Serial.begin(57600);
  pinMode(0, OUTPUT);
  pinMode(2, OUTPUT);
  digitalWrite(0, LOW);
}

void loop() {
  digitalWrite(0, HIGH);
  delay(10);
  int sensorValue = analogRead(A1);
  int r, g, b;
  if (sensorValue > MINLEVEL && sensorValue < BLEVEL + 1) {
    g = (sensorValue - MINLEVEL) / 2;
    b = 0;
  } else if (sensorValue > BLEVEL) {
      g = sensorValue - MINLEVEL;
      if (g > 255) {
        g = 255;
      }
      b = sensorValue - BLEVEL;
      if (b > 255) {
        b = 255;
      }
    } else {
      g = 0;
      b = 0;
    }
  Bean.setLed(0, g, b);
  tone(2, 300 + sensorValue * 10, 20);
}