Show HN: Physical Pomodoro Timer with ESP32 and e-paper screen

Always interested to see a "device" type of project on here -- they tend to be the most challenging, even if the goal is simple. The intersection of object design, electronics and code is a great playground.

I really like the choice of screen, and generally the considerations given (and explained in the readme!) for purpose and usability.

Couple of notes on the object design (and this is something I find very challenging, and spend a lot of time iterating on)

- What if the knob was on top of the device, wide and flat? you could center the screen, make the device smaller, and the physical action of turning it would be less likely to push the box around

- Chamfers and fillets go a long way to make a thing look polished -- it's a small detail, but the difference between a sharp edge and a rounded one somehow seems to matter a lot.

- Since the menu always has three options, what if instead of the knob there were three buttons on the top surface (like the "snooze" of an alarm clock)? Fewer interactions to fiddle with!

- You can get translucent filament, and it makes for very cool "light conduit" parts -- eg, the LED box could be solid, and it would look like something from an 80s dashboard. Alternately, you could print a border for the screen, and light that up instead, making for a more minimalist design.

(Sorry, I can't help it, I like thinking about these things)

How did you design the knob, OpenSCAD? The knurling is a nice touch, and looks like it was done in a programmatic way.

great questions!

- knob: yeah, if I were to redesign that part I would move it to the top. I had a total schedule of 4 weeks for this project, and I didn't feel confident enough to rebuild (and print prototypes) of the case when I encountered the weight problem, but that would definitely make it better

- I did fillet/chamfer (almost) every edge I believe, I also printed the final case with fuzzy skin to make it feel higher quality

- The knob was originally meant to also allow you to change the timer, so having a dial felt like the right thing to do. Didn't turn out that way, so yes three buttons might be the better UX for the menus I ended up with (and would make the device smaller)

- The shroud actually started out as a way to prevent light leaking (and then I re-printed it in white so that it would boost the LED diffusion a bit together with the diffusion plastic film), but I like your idea of having an LED strip around the edges of the screen - didn't think of that!

- I am usually more of a Blender guy, so I followed a tutorial for doing knurling in onshape. The tool really doesn't like that much geometry and is laggy to work with, but feel free to check out the onshape file (linked in the README)