mitxela

Why would one choose to work with a bare computer board atop a layer of tinfoil like this?

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjc1rzfjnK1u35tQpdkuGgBetluIW83iM43HYLbd8hjk7EJLiliyAK03QLu1njtt5gK5buwGQ2tnEkIlvLdALK5qWnTWzmO9rFMQrqQJUR7GFNuyQo1kKT2FC99_UxsVWEQG826KGZ9IQVP_QC_LoqBsxSPdcdeOwZn-2ybybBZl-MCSlmJpqk3s6q__W8/s4080/PXL_20230702_225911600.jpg

Perhaps the tinfoil was clipped to a ground? Would it then be protected from static shocks and other invisible (to the naked eye) damage?

Historically I've used flattened cardboard outside on top of a brick patio, and ensured I touch a grounded circuit before e.g. replacing capacitors. No e-deaths due to static yet, though my equipment is nearly all from ~circa 1999 or newer, and I believe newer equipment typically incorporates some static protections into designs.

TFA's PCB layout connections are so flowy and beautiful, they remind me of a past HN submission about rounded PCB circuit wiring: "Melting KiCad" https://mitxela.com/projects/melting_kicad / https://news.ycombinator.com/item?id=31108652

p.s. this is an amazing writeup, thank you to the OP for submitting and to the author for taking the time and care. Really, really cool. This reminds me a bit of a Ken Sherriff analysis https://righto.com (!) <3

yeah, I was really impressed too. using three.js and .wrl files (vrml I guess, hello again 01994)

the one-finger orbit and 2-finger pan and zoom was fantastic and intuitively obvious. with a mouse it's left-button orbit, right-button pan, and mousewheel zoom, which is not as immediately obvious but still pretty usable

https://mitxela.com/other/3d/loader.js?2

view-source:https://mitxela.com/img/uploads/metal/scaffold/scaffold-case.wrl

incidentally meshlab knows how to open .wrl files, and the loader on this page also supports .stl

surprisingly, this is not a hack of modelviewer.dev, though it uses the same tag name and underlying 3-d library. it supports different model formats and is an independent effort. https://mitxela.com/projects/model-viewer is a page from last month by jacobs about it

no license visible tho, which is a shame because it's awesome and i'd like to be able to use it. still, not that hard to reimplement i guess? now that jacobs has done all the hard and non-copyrightable work of figuring out what kind of user interface and programming interface works best for this

I didn't see that bit, but the layout image[0] shows very large cuts in the ground plane with traces running right over the middle of them, especially between U8 and U7. There's plenty of space here to add some ground traces between them, but that hasn't been done.

> you never really know until you get it tested.

I suspect they haven't given the lack of a CE marking on the board.

As an aside that bothers me a bit given that they say they sold 1000 of the last version, which would easily cover the cost of the (legally required) testing. Normally I'm of the opinion that it's fine to ignore it for some obscure hobby product where the cost of testing would be higher than any expected profits, but in this case they have the money from previous versions of the same product.

[0]: https://mitxela.com/img/uploads/clock/mk4/kicad-screenshot2.png

> If I were making something for this problem I would make an AC-DC-AC converter with a PLL to divide the 60Hz input frequency to 50Hz to control the inverter.

This is the best way to do it, especially if the synchronous motor inside the clock is actually fed with a lower voltage from a transformer (which seems to be common in old radio clocks as they needed a transformer anyway to power the radio circuitry). If that is the case, it should be possible to bypass the transformer entirely and build a converter that operates entirely on low voltage; some quick searching suggests that this exact kind of project has already been done before in fact [1].

[1]: https://mitxela.com/projects/phase-locked_inverter

See also the CH32V003 [0] (more expensive variants also available), a neat, cheap and standalone RISC-V with plenty of modern & flexible peripherals, good package options, single wire debug and an open toolchain [1] for ~20c per.

Mitxela has a great article on them [2] and I totally agree they have a lot of the same joy & simplicity of the ATTiny - but with the added bonus of lots of interesting DMA controller misuse!

The peripherals have a very STM feel (in a good way) which perhaps isn't surprising given WCH's history.

0: https://www.wch-ic.com/products/CH32V003.html

1: https://github.com/cnlohr/ch32v003fun

2: https://mitxela.com/projects/badge

The desireable thing here is that they can fly, not that it's optimal.

also you could just drive, lol this thing:

https://mitxela.com/projects/turbine_transport_transformer

the bigger questing is anyway where this could safely land and start, when it's of no need for sea transport to begin with.

Same question remains for that plane. How to do the last miles from the airport. If the route is long enough you can usually find an autobahn and a river wide enough to get 100m blades around.

There seem little use for planes in that size class that doesn't add costs.