Multiwave: Tone generator using proximity sensors

Hi bigclownians.
Happy Christmas time and PF 2019.

I would like to introduce my project.
I call them multiwave.
It is simple tone generator. Tones will be generated in realtime (to D/A converter with connected earphone(s)) based on measured distance using a pair on HC-SR04P distance sensors.

Tones are simply cosine waves on multiple frequencies.

First proximity sensor control frequency of cosine waves => frequency of tones.
Second proximity sensor controls loudness.

Project stages
  • [spoiler]Proof of concept.[/spoiler]

  • [spoiler]Early prototyping stage[/spoiler]

  • Prototyping stage. (2018-12-29T23:00:00Z)

Some aspect of project has been already discussed here and here.

Things used in this project

What’s working now.


  1. Generating sine / cosine wave in real-time working in progress.
  2. Tuning loudness logarithmically.
  3. Project and print enclosure.
  4. Manny minor stuff.
Photos of prototyping stage.

Generating tones to earphone(s).

Measuring distance with logging to console.

Possible extensions

  1. Tuning frequencies logarithmically.
  2. Measured distance shown on smart led strip inspiration here and codes here all credits to @martin.grames.
  3. Generating tones from white noise using filter(s).

Thanks @hub.martin for advices and support.
Thanks @martin.grames how proximity sensors workaround and support.

This project is optional task for the courses Signals and Systems taught at FIT BUT.
All ideas and notes welcome! :wink:


Updates nr. 1 6urop6/Prpmgu6.:

Development stage video.

Hello Matouši,

thank you for sharing of your project and future ideas. And also for this awesome really detailed write-up (I know what it takes:) ). I’m really curious which sounds your code can generate. Can you share a video with your hands moving in front of the sensors?

I’m curious how the real-time signal generation will work. Are you using only single DAC output, or both of them?

We wish you nice holidays and all the best in new year and good luck with the upcoming exams.
BigClown Team.

Hello Martin,
thanks for your interest and wishes. I will post video 2018-12-30T23:00:00Z I hope.

I’m using single DAC output actually.

Actually I have no free time because of upcoming exam but I hope I will upload video laterly this week. :wink:

As I promiss here is the video.

(Second post updated. :wink:)

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