The Micro:bit Accelerometer Theremin. Cool case, but no lights this time. (All Images: ME)



Continuing on the theme of the Accelerometer Tone Adjusting project, I want to use the idea of very little hardware in building another Theremin. You can see the Micro:bit Light Based Theremin project after this link. I also made an ADVANCED Light Theremin after this link.

The Theremin is a constantly adjusting tone based on some sort of analog input, in most cases. Instead of using light to adjust what the Theremin is doing, I figure I could use the onboard accelerometer. I liked the accelerometer option a little better than the light one. It’s a bit more dynamic, I suppose.


The software works as follows:

- Power it up, it will play tones.

- Move the Micro:bit around to hear the sounds change.




First, let’s gather all the necessary components you’ll need to build this project.

1x BBC Micro:bit

1x 3.5mm Audio Jack

1x 5v 2A power supply



Laser cutter to cut the case


Video demonstration of the project:



Load the code onto the Micro:bit.

I am providing the hex file you need to drag and drop onto the Micro:bit, and the python code as two separate files. For the below process, just use the hex file.

Plug the MicroUSB cable into the Micro:bit, and plug the other end of the cable to a PC or MAC.

At this point, you are going to copy over the code to the Micro:bit. I am providing the program (code) in this post that needs to be copied over. When the Micro:bit plugs into a computer, it shows up as a USB flash drive. All you have to do is copy the file over to the Micro:bit, like it’s a USB Flash Drive, and the Micro:bit will reset, and the program is active.

You can remove the Micro:bit from the computer at this point. The program will start running, and without the rest of the circuit, it will not function.

A little bit about the code:

This is the whole program! I was surprised how clear and succinct the concept's code turned out.



I like this project a lot, since it doesn’t have a lot of steps and parts. Following is the only wiring you have to do.

Wire up the audio connector.




- Plug in powered speakers to the 3.5mm jack.

- Power it with a 5V microUSB cable from either a PC, outlet or battery. It will immediately start playing.

- Move the Micro:bit around to hear the sounds.




This is somewhat of a proof of concept project. It’s completely possible to make a Theremin this way. Now it’s time to take it to the next level.