Theremin

Challenge

In this exercise, we are recreating an electronic musical instrument from the 1920s. We will play a musical note which changes based on how we move the microbit around in space. Wire a speaker or a pair of headphones between pin 0 and the GND pin on the edge of the microbit before running.

Requirements

• Crocodile clips and a speaker or headphones to play the music through.

Notes

• pitch - music.pitch plays a note at a given frequency. A above middle C is 4400Hz.
• accelerometer - the microbit has an accelerometer like you will find in a modern smartphone that enables it to know which way round it is in space - upside down, tipped forward or back and how high above the ground it is.

Extensions

• Change the starting note
• Play only notes from a scale.
• Change the scaling calculation to change the range of the notes it can play.

Example Solution

Show Solution

from microbit import *
import music

# where am i in space?
def calculate_movement():
    scaling_factor = 20
    x = accelerometer.get_x() / scaling_factor
    y = accelerometer.get_y() / scaling_factor
    z = accelerometer.get_z() / scaling_factor
    movement = x + y + z

    return int(movement)

frequency = 440 # concert 'A'

while True:
    change = calculate_movement()
    pitch = frequency + change    
    music.pitch(pitch)
    sleep(100)