A few funny projects using my simplified implementation of DFT

Bilexa Bass – Singing Fish, Sound-Actived 3D-printed Vibrator and Scared Spider Toy. I wanted to highlight these funny (sometimes crazy!) projects as they are using my version of simplified implementation of DFT I created for project ATtiny13 – dance lights with DFT and because the authors are very idea-driven, original and just awsome.

Bilexa Bass – Singing Fish (Bob, ATtiny84)

This project has embeded Alexa inside and uses an ATTiny to perform all the logic, which includes a photoresistor for detecting when the light ring is illuminated, and audio input for detecting the audio, running a DFT (Discrete Fourier Transform), and controlling the mouth and body motors. The project link – https://hackaday.io/project/73048-bilexa-bass.

Sound-Actived 3D-printed Vibrator (Raphael, ATtiny13)

Well, I got an email from Rafael with title “Pleasure with simplified DFT”. At first glance, it did not look like crazy project. But it was! Rafael explained that he wanted to design an original and funny gift for a friend (her).

The way Rafael described the project was also so funny. He really made my day. Bellow is the content.

Hello Lukasz!

First of all, thank you for uploading your ATtiny DFT project to the Internet, i always wondered if this would be possible.
I am pretty sure that you are interested in what happens with your code and schematics when you share it with strangers over the internet. Well, a friend of mine had her birthday and i needed a funny present for her, so i used your project to create a sound-activated 3D-printed Vibrator, where you can plug in your aux and plug it in 🙂
I attached some Videos of it (dont worry, its only the vibrator on my workbench – no unappropriate footage).
For the electronics, I used exactly the same schematics as you uploaded, but with transistors and motors instead of the LEDs.
If you want the design files for this apparatus, just let me know, i’ll send them to you (PCB in EAGLE, 3D in FreeCAD).
Please let me know what you think of this project and if you would have thought that your project might lead to something like this somewhere on this planet 🙂

Anyway, from the technical point of view it’s very interesting project – combines mechanical and electronics aspects and requires a lot of skills. Thank you Rafael!

Scared Spider (Steve, ATtiny13)

This project uses ATtiny13, a toy has 6 leges and has implemented sound-activated motion. The louder voice is the spider is more “scared” and is moving faster. Unfortunately Steve did not send a pics of final result.

Disco Lights (ESP8266)

This is one of my projects that uses ESP8266 to process realtime DFT and PWM. The result is quite good, I think. The code is on GitHub.


I got some comments and emails that make me think that simplified DFT alghorithm is kind of black-box. Soon, I will post an article that explains step by step how it works (update: https://blog.podkalicki.com/twiddle-factor-based-dft-for-microcontrollers/)

Many thanks to all of you who sent me a messages and/or pictures of your projects that use the code from my examples. I really like that kind of emails. It make me know that my code is helpful and likeable.

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