Show HN: Strange Attractor on an Etch a Sketch with Raspberry Pi Pico

If you are interested in both CNC and Etch-a-Sketches, Youtuber <i>This Old Tony</i> has a great introduction to CNC hardware and software where he build a computer controlled E-a-S with pro-grade hardware and software (Mach 4). It is very entry level, 60 minutes in two parts.<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=K0XfRPi_h2M" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=K0XfRPi_h2M</a> (part 1)<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=eLdlV3-JaH8" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=eLdlV3-JaH8</a> (part 2)

Some additional documentation here: <a href="https:&#x2F;&#x2F;vha3.github.io&#x2F;Pico&#x2F;Steppers&#x2F;Lorenz.html" rel="nofollow">https:&#x2F;&#x2F;vha3.github.io&#x2F;Pico&#x2F;Steppers&#x2F;Lorenz.html</a><p>I&#x27;ve been experimenting with the PIO (Programmable I&#x2F;O) system on the new microcontroller from Raspberry Pi. These are coprocessors for which the user can write code in a bespoke assembly language (PIOassm) to drive the GPIO ports. You can do really interesting stuff with these, like implement high-speed communication protocols (e.g. VGA) or offload tasks like driving stepper motors.<p>I&#x27;ve also been really interested in fractals and chaotic systems. For me, they&#x27;re a nice bridge between interests in engineering and art. That&#x27;s why this is drawing the Lorenz system in particular.

Here&#x27;s the source for my relatively recent ESP32-based Etch-a-Sketch build: <a href="https:&#x2F;&#x2F;github.com&#x2F;derekenos&#x2F;iome&#x2F;tree&#x2F;master&#x2F;appliances&#x2F;sketchy" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;derekenos&#x2F;iome&#x2F;tree&#x2F;master&#x2F;appliances&#x2F;ske...</a><p>More pics&#x2F;vids: <a href="https:&#x2F;&#x2F;derekenos.com&#x2F;project-sketchy" rel="nofollow">https:&#x2F;&#x2F;derekenos.com&#x2F;project-sketchy</a>

Looks like a bit of slack in the belts, is there a way to tighten it up or account for it in software?

Thanks for sharing this, this is really cool! I saw you posted a lot of details on the software, but could you expand on the hardware? Do you have any reference on the stepper motor setup&#x2F;components used to control the two dials?

This makes me curious about the possibilities of using an Etch-a-Sketch screen as a low-end sort of e-ink display. How well could one of those screens be utilized? Sounds like a fun weekend project.