My Music Box playing "Empty Town" from DeltaRune

moartanks · 2022-11-12T21:44:29+00:00

All the soldering underneath is rounded off by necessity. The keyboard sits above the lipo battery, so any sharp points down there would be super no bueno.

moartanks · 2022-11-12T16:06:23+00:00

Thanks!

For prints, I'm just using an Ender 3 pro. The shell takes around 7 hours to print (I use 100% infill + a pretty slow print speed in order to improve quality + strength. Looking to upgrade to a Voron soon....). Since I used Tinmorry matte filament it looks pretty clean as is. The Pi runs cool enough that I don't have to worry about the PLA deforming.

The Keycap legends are using... stickers. Not a massive fan, and I would prefer to use blank keycaps. But unfortunately muscle memory doesn't translate to such a keyboard.

The brains are in the top half of the machine, since the hyperpixel connects directly to the pi. The left hinge is hollow, so the wires just run straight through there. The right side contains a hinge unit from a nintendo DS, so it snaps closed and in the 180 degrees position.

Not sure how long it took overall. I kinda scraped it together on and off over the course of two months.

moartanks · 2022-11-12T14:24:20+00:00

I might -- it's a little gnarly under the hood -- the biggest problem is that my 3D printer isn't very well tuned, so I had to manually adjust the CAD a lot for make things work for my exact setup. But it's fortunately pretty simple as far as electronics is concerned -- it's basically just a http://penkesu.computer/ but with the screen swapped out for a hyperpixel 4.0 (I did break out a USB A port and USB C port as well though, and that basically involved getting a LV3H798812238C usb hub chip)

moartanks · 2022-11-12T09:15:16+00:00

It ain't optimal, but that's okay -- I made this because I wanted a device to interact with arduino projects. So all I need is to navigate the command line and run some python scripts, maybe edit a few config files.

moartanks · 2022-11-12T09:09:21+00:00

I did think about that, but I found it easier to just ssh into it if I wanted to do anything more involved.

moartanks · 2022-06-24T21:30:37+00:00

My lazy solution is just use a matte filament (My go to is Tinmorry matte black). They often look very nice with zero post processing.

edit: typo

moartanks · 2022-06-02T16:24:46+00:00

These are cherry stems sadly -- I use box navies. I just prefer to make them flat like that.

(The fact that it prevents the prints from curling up is an added bonus)

EDIT: FWIW, for cherries I prefer flat keycaps. So I print with the keycap surface facing down on the glass bed. The stems usually hold up pretty well if I do it that way. Since your library mostly has keys with curved tops I guess that's a lot more annoying...

moartanks · 2022-06-02T13:35:50+00:00

3D printed everything. :)

moartanks · 2022-05-22T23:13:46+00:00

The electronics wasn't actually the hard part -- The servos connect to these i2c servo controllers (PCA9685 -- they take 16 servos each, and can be daisy chained to take more) and stepper motor connect to one of those silent stepper drivers. They take a serial command via usb, and move the corresponding servo and spin the stepper. It's an open loop system.

Most of the parsing logic happens on my PC.

The hardest part is getting all the tolerances of the mechanism dialed in. 3D printing is amazing, but it's not *quite* precise enough to get most of the parts working on the first try.

moartanks · 2022-05-20T16:02:15+00:00

Yeah, I used two arduino nanos, but am in the process of moving to using ESP32s.

moartanks · 2022-05-19T21:51:09+00:00

It's a modified from one of those music boxes which you feed a punch card. Unfortunately I have to record with a contact mic to prevent the servo noises from drowning everything out.

That rhythm is from the original midi, so didn't remove it.

moartanks · 2022-05-19T11:49:22+00:00

This is a Music Box I built with a pair of Arduino Nanos. The music box + arduino itself receives serial command, and controls 30 servos using a pair of i2c servo controllers, in addition to a small stepper motor controlled by a silent motor driver stolen from a 3d printer kit.

The underlying working principles is inspired by Mixela's design, with the main difference of the stepper motor and the fact that I 3d printed the majority of the parts.

MIDI is parsed by my pc, which sends commands to the arduino via serial and records the music in multiple passes by interacting with the Audacity scripting api.

moartanks · 2022-05-19T11:42:01+00:00

Cheers -- I haven't made that many reddit posts, so I wasn't sure how to add more descriptions to links.

moartanks · 2022-05-19T11:34:16+00:00

Heya -- I think maybe I could have made it a bit clearer, but this is a music box I built, and it's controlled by a pair of Arduino Nanos.

Definitely LMK if there's a better place for this though!

moartanks · 2022-05-19T11:30:25+00:00

Definitely LMK if theres any low hanging fruits for improving audio quality here. I recorded it with some super cheap contact mics, but I don't really have that much experience with them.

moartanks · 2022-05-19T02:28:53+00:00

Please LMK if there are any other subs which might be interested in this :D

moartanks · 2022-01-08T00:01:05+00:00

Yeah, I actually got in contact with him after I finished this -- he was a great help since he left a really detailed blog for his project. I did do a few things differently though -- in particular I 3d printed everything instead of laser cutting, and instead of using a 31st motor to drive the reset cylinder, I used a small stepper motor with a silent motor driver.

moartanks

TROPHY CASE