Arduino Lab 6: Theremin

Background: A theremin is an electronic musical instrument controlled without physical contact by the performer. See a performance here. We are going to make a fairly rudimentary version of this using a photocell. This project falls more in the realm of wellness. It's fun to play and you can create all sorts of sounds!

Goal: Create a theremin using a photocell.

 

Circuit Setup

• Materials
  • 1x Photocell
  • 1x 10 kOhm Resistor
  • 1x Piezoelectric speaker (buzzer with bare contacts and circuit board material on the underside, looks different than below).
• Setup
  
  • Connect photocell between 5V and A0.
  • Connect resistor between A0 and GND.
  • Connect “+” side of speaker to digital pin 2.
  • Connect other side of speaker to GND.

 

 

Lab Instructions

• Configure serial port to be used.
• Use analogRead() to read analog voltage in circuit.
  
  • Provides a value between 0-1023 corresponding to a voltage.
  • Store this value to a variable.
• Use the analogRead() value to play a sound using the tone() function:
  • tone(pin, freq) – plays a note at the specified frequency.
    
    • pin – the pin we want to play the sound from (pin 2).
    • freq – the frequency of the note we want to play.
  • Below describes the frequency ranges of a keyboard. You may need to scale or adjust the analogRead() value to play good audible frequencies.
    • The notes on a piano range in frequency from 32 to 4186 Hz.
    • https://en.wikipedia.org/wiki/Piano_key_frequencies