Andrew Huang's Blog, page 6

Name that Ware, January 2024

The Ware for January 2024 is shown below.

I picked up this little gizmo at a junk shop in Akihabara. I actually have no idea what the original purpose was, so I’m curious to see if anyone can convince me as to what this thing did, presumably for many years and millions of times. I got it mostly because it was a great price for a linear guide plus associated optical interrupters and motors (although I think the central motor’s bearing is busted, hence its junk shop fate). Fortunately the mounting patterns for these kinds of mechanical parts are almost, but not quite, standardized.

Winner, Name that Ware December 2023

The Ware from December 2023 is a 20-watt laser diode used for engraving. It’s used in products like the ATOMSTACK Laser Engraver (link without affiliate code), and the module itself is produced by Shenzhen Xinghan Laser Technology Co, Ltd.. I don’t have an exact part number for it, but it is a blue-wavelength (so presumably 450nm), quad-laser diode module with a net power output of around 20 watts. I recently saw a LaserPecker (sans affiliate) in action and it’s impressive how solid state lasers have transformed engraving/cutting technology — my first laser cutter from 20 years ago was the size of a desk, cost over 10x as much, and was a lot harder to use.

As for a winner, it’s pretty tough to pick one since a I found several comments quite insightful. The main thing I personally wanted to figure out was the structure of the picture above: why was there a smaller device stacked on top of a larger device? I originally thought the gray-ish lower substrate was the laser, and the small part on top was a protection diode; but after reading the comments I’m now of the opinion that it’s probably a CVD diamond heat spreader, and the laser is the very small black-ish bar on top.

I found another image I had in my collection of the device lasing, and indeed the small bar was the part that was emitting light. It’s also the case that the lasers are at stepped heights. If memory serves correctly, the beam shape of these laser diodes tends to be rectangular, so by “stacking” the beams next to each other you can get a more square profile to the net output pattern. I was also surprised not to find any sort of optical feedback mechanism for power monitoring, or obvious protection diodes — but maybe the control circuitry and fabrication process is just so dialed in now that it’s not necessary? Or perhaps something else very clever is going on that’s not discernible in these photographs.

It’s a tough call, but I’ll give the prize to FETguy — for convincing me that the lower chips are probably CVD diamond, and noticing the stair-step structure. Congrats, email me for your prize!

As a brief postscript, looking at all the progress in high power laser diodes made me wonder if cheap HDI PCBs are around the corner (I have a blog post that goes more in-depth into HDI PCB construction, in case you’re interested). The biggest capital cost barrier has traditionally been the huge laser CNC machines needed to cut the vias, compounded with the fact that these expensive CNC machines can only drill a single board at once (as opposed to the mechanical drills that can penetrate a stack of ten or more PCBs in a single drill hit).

Unfortunately, it looks like we’re still an order of magnitude away in terms of the peak power and beam profile necessary to drill a good, clean hole in an HDI substrate, but it also looks like there’s plenty of manufacturers with their eye on this niche. A cursory review of the literature also seems to indicate that whatever is being used to drill the holes probably has to retain at least one mechanical axis (with perhaps a single galvo plus a parabolic reflector) because a two-galvanometer solution will have problems with the laser spot impinging at an angle toward the edges, which is undesirable for a PCB via.

Name that Ware, December 2023

The Ware for December 2023 is shown below.

Thanks to Cedric Honnet for contributing this ware! Unfortunately this image does have an exact hit on Google images, as it is already in Cedric’s social media feed — but I think the ware itself is functionally interesting, yet simple enough to guess without having to rely on image searches.

Thus answers will be judged in part based on their insight into the reasoning behind the construction of this ware — for example, what’s going on in the zoomed in view of the ware? What are some of the considerations in building a module of this nature?

Happy new year! Name that ware will be wrapping up its 18th year soon .

Winner, Name that Ware November 2023

The Ware for November 2023 is a Lucira at home Covid test. Congrats to Jon Neal for nailing it, email me for your prize!

Here’s some more images of the ware for your enjoyment.

The New Essential Guide to Electronics in Shenzhen

Some might remember a book I released in 2016, “The Essential Guide to Electronics in Shenzhen”. A lot has changed in the world since then, and Shenzhen is no exception.

There’s a new maintainer of the guide, Naomi Wu (@realsexycyborg), and she is crowdfunding an updated, new version with a snazzy red cover, called “The New Essential Guide to Electronics in Shenzhen”. While the technical Chinese terms haven’t changed much, a lot has changed in the culture and ways to do business; her new text gives pointers on how to engage on Wechat, digital etiquette in China, updated maps, and much more.

If you enjoyed The Guide in the past, or hope to visit the electronics markets in Shenzhen in the future, you can reserve your copy today.

Name that Ware, November 2023

The Ware for November 2023 is shown below.

Thanks to “zw” for mailing me this device to take apart and share!

Winner, Name that Ware October 2023

The Ware for October 2023 is a Seiko DS-250 keyboard synthesizer.

Nobody guessed the exact make and model of the keyboard, but it was really entertaining to see the comment thread puzzle through the design. The dual 8049’s caught my attention too, as well as the lack of obvious DACs. I have some partial photos of the associated I/O board, and it also lacks an obvious DAC — mostly just generic mixer/amp/analog switch components on there, so I’d agree with the idea that the DAC could be integrated into one of the big Toshiba chips (or perhaps they are doing something with PWM).

I’ll give the prize to Cary Roberts for being the first to guess the general class of ware (congrats and email me for your prize!). Lots of attention to detail to what I had accidentally left in the background after the crop, I didn’t even notice the rollover diodes in the background until someone pointed it out!

Thanks again to JeffreyO for contributing these photos!

Regarding Proposed US Restrictions on RISC-V

A bipartisan group of 18 lawmakers in the US Congress have recently amplified a request to the White House and the Secretary of Commerce to place restrictions on Americans working with RISC-V (see also the initial request from the Senate) in order to prevent China from gaining dominance in CPU technology.

The request is facially misguided; any restrictions would only serve to reduce American participation in an important emerging technology, while bolstering ARM’s position as an incumbent near-monopoly provider of embedded CPUs.

When the first report came out, I hoped it was just a blip that would go away, but with the broader bi-partisan group asking for restrictions, I felt I could no longer just stand by and watch: I am an active participant in the RISC-V ecosystem. I’m also subject to US law.

I did the one thing any American can do, which is write a letter summarizing my thoughts on the issue, and sending it to the White House, Department of Commerce, and the relevant members of Congress. Unfortunately, I don’t have a PAC, lobbyists or any sort of high-level connections to US politicians, so I don’t have much hope the letter will be received in time.

However, I do have a blog. I’m posting a copy of the letter I sent to the White House here, in far-flung hopes that maybe someone with more political connections than I might pick it up and send it on.

Finally, if you disagree with my stance or have a different perspective, I also encourage you to send a letter expressing your thoughts to various government officials. It doesn’t have to be “my way”, but a show of broad public interest in the topic may at least encourage policymakers to think a bit more carefully about the issue, and to hear out more perspectives.

The Letter

To President Biden and the White House staff:

Recently, a letter was sent to the White House and the Secretary of Commerce by 18 lawmakers asking how the US plans to prevent China “from achieving dominance in … RISC-V technology and leveraging that dominance at the expense of US national and economic security”.

I am a Michigan-born American with a PhD from MIT in electrical engineering. I’m also a small business owner who designs and manufactures electronics. I am writing to urge you to not place any restrictions on the sharing of RISC-V technology.

My products’ CPUs are based on the open source RISC-V standard. RISC-V’s openness specifically benefits small businesses such as mine. I get tools and designs from the open source community, and I contribute my improvements back to the pool. Barrier-free participation in this vibrant open source ecosystem keeps overhead low, allowing me to be competitive in the cutthroat hardware business.

Like the Internet, RISC-V is already a global phenomenon. There are already prolific contributions from the EU, India, China, and more [1]; the US is not the sole proprietor of RISC-V implementations. I use an implementation of RISC-V called the VexRiscv, which is developed in the EU. Any barrier for US persons’ participation will only slow American progress in developing and adopting this technology. It will have an effect opposite of that intended by lawmakers.

A further subtlety is that RISC-V is simply a standard. It defines a set of words used to tell a chip to do something, similar to how we rely on a dictionary to define the meaning of English words. Just as one can write secret documents using openly defined words, designs using the RISC-V standard can be proprietary, even if the standard is open. The benefits of open standards are so well established that the US has an entire agency – NIST – to promote American innovation and industrial competitiveness by publishing open standards.

Furthermore, it is not practical to police the use of an established standard: once a book is published, it is impractical to ensure that none of America’s enemies obtain a copy of it. This has long been a trade-off of American innovation philosophy: we can freely exercise our First Amendment rights to share ideas, creating a vibrant intellectual exchange, even at the risk of others benefiting from reading our textbooks, journals and patents.

I believe this trade-off has been in our favor. With every exchange – even with potential competitors – we learn more. Chilling our freedom of expression to achieve administrative outcomes is a page out of other more oppressive regimes’ playbooks: it is fundamentally un-American to restrict the flow of ideas.

In summary, any restrictions placed on US persons sharing RISC-V technology would only serve to diminish America’s role as a technological leader. Over-broad restrictions could deprive educators of a popular tool used to teach students about computers on American campuses, for fear of also accidentally teaching to an embargoed entity. And even narrow restrictions on RISC-V could deprive US tech companies with any potential exposure to the Chinese market of access to a cost-effective, high-performance CPU technology, forcing them to pay royalties to the incumbent near-monopoly provider, ARM Holdings plc – a company that isn’t American. This weakens American competitiveness and ultimately harms the US’s best interests.

If the administration agrees that RISC-V is a technology so critical to US economic and military interests that it deserves special attention, instead of trying to restrict its expression with a federally-mandated licensing regime, it should invest in programs to develop more home-grown American RISC-V chip maker success stories. It is already within the four corners of existing US legal framework, and the RISC-V contractual framework, for companies to choose to develop proprietary implementations of RISC-V CPUs. The US has strong precedents for companies navigating the boundaries of open standards and finding success without the need for federal guidance: Intel and AMD are American industrial juggernauts built around proprietary implementations of an otherwise openly documented “x86” computer standard. What the US needs is an American answer to ARM Holdings plc’s monopoly, and that answer comes from investing in US companies that embrace RISC-V.

President Biden, I urge you: have faith in American innovation. Have faith in American values. Do not place any restrictions on the sharing of RISC-V technology. We can work together to build more US chip maker success stories, while embracing the American value of freedom of expression!

Very truly yours,

Andrew ‘bunnie’ Huang
An American Hacker, Maker, and Author

[1] https://github.com/riscvarchive/riscv...

Name that Ware, October 2023

The Ware for October 2023 is shown below.

Thanks to JeffreyO for contributing this ware!

Winner, Name that Ware September 2023

The Ware from September 2023 is a Honeywell HPMA115S0-XXX PM2.5 sensor. Although Ben guessed the general category of the ware first, David was the first to give the exact model. Usually I award the prize to the first person to give an exact, correct model number and fall back to category-of-ware only if no correct model number was named. So, congrats to David for nailing the exact make and model of the ware. email me for your prize!