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The Raspberry Pi Pico…and a Tiny Plug-In Pi

Yesterday the Raspberry Pi Foundation announced the Raspberry Pi Pico, at the boggling temporary low price of…$4US. It’s definitely a microcontroller on the order of an Arduino rather than the high-end 8GB RPi that might stand in for a complete desktop mobo. And that’s ok by me. The chip at its heart is new: the RP2040, a single-chip microcontroller designed to interface with mainstream Raspberry Pi boards, and lots of other things.

Raspberry-Pi-Pico-at-an-angle-500x357.png

Now, what caught my attention in the page linked above was the list of partner products made by other firms using the same RP2040 chip. Scroll down to the description of the SparkFun MicroMod RP2040 proccesor board. It’s still on preorder, but look close and see what’s there: an edge connector…on a board the size of a quarter! That’s not precisely what I was wishing for in my previous entry, but it’s certainly the right idea.

17720-MicroMod_RP2040_Processor_Board-04.jpg

As I understand it, SparkFun is turning the RPi-wearing-a-hat on its ear, into a hat-wearing-an-RPi. The M.2 interface used in the product is actually a standard developed some years back for use in connecting SSDs to tiny slots on mobos. I knew about M.2, but wouldn’t have assumed you could mount a CPU-add-in board using it. Well, shazam! Done deal.

The RP2040 chip is a little sparse for my tastes. I want something I can run FreePascal/Lazarus on, over a real OS. I don’t see anything in the M.2 spec that would prevent a much more powerful processor board talking to a device (like a keyboard, TV or monitor) across M.2. The big problem with building a high-end RPi into things is keeeping it cool. The Foundation is aware of this, and did a very good job in the $100US Raspberry Pi 400 Pi-in-a-keyboard. (This teardown and review is worth a look if you’re interested in the platform at all. The author of the teardown goosed the board to 2.147 GHz and it didn’t cook itself.)

I fully intend to get an RPi 400, though I’ve been waiting awhile to see if there will soon be an RPi 800 keyboard combo with an 8GB board instead of 4GB. Given the price, well hell, I might as well get the 4GB unit until an 8GB unit appears.

So consider my previous post overruled. It’s already been done. And I for one am going to watch this part of the RPi aftermarket very carefully!

Proposal: A New Standard for Encloseable Small Computers

Monitors are getting big. Computers are getting small. I think I’ve mentioned this idea before: a cavity in a monitor big enough to hold a Raspberry Pi, with the monitor providing power, video display, and a couple of USB ports for connecting peripherals like mice, keyboards, and thumb drives. Several of my Dell monitors have a coaxial power jack intended for speaker bars, and a USB hub as well. I’ve opened up a couple of those monitors to replace bad electrolytics, and as with most computer hardware, a lot of that internal volume is dead space.

The idea of a display with an internal computer has long been realized in TVs, many of which come with Android computers inside. That said, I’ve found them more a nuisance than useful, especially since I can’t inspect and don’t control the software. These days I outsource TV computing to a Windows 10 Intel NUC sitting on the TV cabinet behind the TV.

The top model of the Raspberry Pi 4, with 8 GB RAM, is basically as powerful as a lot of intermediate desktops, with more than enough crunch for typical office work; Web, word processing, spreadsheets, etc. With the Debian-based Raspberry Pi OS (formerly Raspbian) and its suite of open-source applications, you’ve got a desktop PC. More recently, the company has released the Raspberry Pi 400, which is a custom 4GB RPi 4 built into a keyboard, with I/O brought out the back edge. (In truth, I’d rather have it built into a display, as I am extremely fussy about my keyboards.) Computers within keyboards have a long history, going back to (I think) the now-forgotten Sol-20 or perhaps the Exidy Sorcerer. (Both appeared in 1978.)

What I want is breadth, which means the ability to install any of the modern small single-board computers, like the Beaglebone and its many peers. Breadth requires standardization, both in the monitor and in the computer. And if a standard existed, it could be implemented in monitors, keyboards, printers, standalone cases, robot chassis, and anything else that might be useful with a tiny computer in its tummy.

A standard would require both physical and electrical elements. Electrical design would be necessary to bring video, networking, and USB outside the enclosure, whatever the enclosure is. (I reject the bottom-feeder option of just leaving a hole in the back of the enclosure to bring out conventional cables.) This means the boards themselves would have to be designed to mate with the enclosure. What I’m envisioning is something with a card slot in it, and a slot spec for video, network, i2s, and USB connections. (GPIO might not be available through the slot.) The boards themselves would have slot connectors along one edge, designed to the standard. The redesigned boards could be smaller and thinner (and cheaper) without the need for conventional video, network, audio, and USB jacks. (Network connectors are increasingly unnecessary now that many boards have on-board WiFi and Bluetooth antennas.) Picture something like the Raspberry Pi Zero with edge connectors for I/O.

Defining such a standard would be a minor exercise in electrical engineering. The big challenge would be getting a standards body like ANSI interested in adopting it. The Raspberry Pi Foundation has the engineering chops, obviously, and once a standard has been created and proven out, groups like IEEE or ANSI might be more inclined to adopt it and make it “official.”

I understand that this might “fork” the small-board computing market between GPIO boards and non-GPIO boards. Leaving the GPIO pads on the opposite edge of the board is of course possible, and would allow the board to be enclosed or out in the open, or inside some other sort of enclosure that leaves room for GPIO connections. A big part of the draw of the small boards is the ability to add hardware functionality in a “hat” that plugs into the GPIO bus, and I don’t want to minimize that. I think that there’s a market for non-GPIO boards that vanish inside some larger device or enclosure that provides jacks for connections to the outside world. The Raspberry Pi 400 is an excellent example of this, with GPIO header access as well. What I’m proposing is a standard that would allow a single enclosure device to be available to any board designed to the standard.

Ok, it would be hard–for small values of hard. That doesn’t mean it wouldn’t be well worth doing.

Odd Lots

  • Amazon is selling hand-made (in Latvia) steampunk thumb drives incorporating copper pipe caps and a Soviet-made pentode vacuum tube. LEDs light up the glass from the bottom of the tube when there’s power available at the USB connector. (Thanks to Bill Meyer for the pointer.)
  • Tonight would be a good night to see Mercury. It’s never easy because the planet never gets too far from the Sun in the sky, but with smartphone apps like Sky Map (on all Android phones by default) it’s certainly easier than it once was. Start by finding Venus in the west, immediately after the Sun goes below the horizon. (You can’t miss Venus.) Mercury lies roughly on a line between Venus and the Sun. There are no bright stars in that part of the sky, so if you see a star near that line, it’s not a star but ol’ Merc himself.
  • Speaking of the Sun… Here’s a solid overview of the history of solar science. It’s a long piece, and even if you choose not to read it, the photos and diagrams are worth the visit.
  • Betelgeuse continues to dim for unknown reasons. It’s fallen from 10th brightest star in the sky to 24th brightest. Orion is the first constellation I can clearly recall seeing, and these days, it just looks…off. This may mean it’s about to go supernova…for large values of “about.” (Hundreds or more likely thousands of years. Stars are never in a hurry.)
  • I’ve been following the coronavirus epidemic using a dashboard maintained by Johns Hopkins. Who knows how accurate it is, but one does get a feeling that China is currently in a world of hurt. I got the link from my friend Charlie Martin, and he’s got a good article about the issues involved.
  • This is a little weird, but it’s one more telltale that the technical publishing industry I loved for so long is no longer with us. I went searching for a book on installing, configuring, and customizing the MediaWiki software, and found…nothing. There’s plenty online, but I’m talking about book-length treatments. If you know of one let me know. My longstanding heuristic is that if it’s not on Amazon, it isn’t available.
  • How to turn a waterway into wine. At least it wasn’t a Zinfandel.
  • Ah, but this was a sweet, sweet hack: Some guy wandered around downtown Berlin pulling a little red wagon full of smartphones, all running Google Maps. Wherever he happened to be during his wander, Google Maps reported a traffic jam.
  • If politics bores you as much as it bores me, here’s a solid distraction from all the tiresome yelling and screaming: The economics of all-you-can-eat buffets. Eat quick: My instincts tell me that as a category buffets are not long for this world.
  • Finally, you’ve heard me say that there’s funny, there’s National Lampoon funny, and then there’s Babylon Bee funny. This may be one of the Bee’s best pieces yet–given this season’s nonstop nonsense.

The End of Owgust

My father had a saying. (Actually, he had a lot of sayings, most of which you’ve long since heard.) This one I’m pretty sure he got from his mother, my grandmother, whom I heard use it a number of times: “The end of Owgust.” (If it came from Sade Prendergast Duntemann, it could well be an Irish thing; I don’t know.) It just means we’re coming to the end of something generally good, like summer vacation, which in truth used to last until the end of Owgust, but now often ends barely after Owgust even begins.

Here in Arizona, the end of Owgust is seen by many as a feature rather than a bug, since by a lot of Arizona people’s reckonings, Owgust begins in May and lasts until mid-September. By Labor day, most people would like to see nightly lows in the 70s again, so we can open our windows at night.

Carol and I tend to get a little tired of our four-month long Owgust as the end approaches, and we were planning to drive up to Colorado to spend some time with friends and see what air in the 60 degree range feels like again.

Not this year.

Our poor QBit was diagnosed with lymphoma a couple of months ago, and we can see his steady decline. We don’t know how long we’ll have him, but it’s unlikely to be more than another month or two. We didn’t want to subject him to an 850-mile road trip, so we stayed home and spent more time in the pool. Lymphoma was what took out our very first bichon, the famous Mr. Byte, in 1995, and is evidently the commonest cancer in dogs. We gave Mr. Byte doggie chemo, but it only bought us a few additional months with him, and made him pretty sick at times. We’re not going to do that again.

So if I’ve been a little short on manic enthusiasm lately, that’s most of the problem.

Other things are going pretty well. Little by little I’ve been getting used to the nasal pillows mask for my APAP machine, which is reporting AHI values generally less than 1, and here and there actually 0. I’m using the great free program Sleepyhead, which displays graphs of your AHI, whatever events it had to handle, mask pressure and leaks, and much more. If you use a recording C/A/BiPAP machine with a compatible SD card format, check it out. It’s told me a number of interesting things, like the fact that events cluster at the end of the night for some reason, and that I record more events when I sleep on my left side than on my right. Highly recommended.

I had some time to play around with my dirt-cheap HP dc7900 Ultra-Slim PC, and liked it so much I ordered another one. The first one was cheap at $37 (I had to provide a hard drive and Win7) but when I went out and looked again on eBay, I found a complete system, including a 64-bit dc7900 with a hard drive and Windows 7, plus power supply, keyboard, mouse, monitor stand, and a 19″ HP flat-panel monitor. The price? $65. For the woiks. Ok, I had to pay another $25 shipping, but that means I got a complete system dropped on my porch for $90. (Stock photo above, but that’s exactly how it looks, granted that the cables aren’t shown.)

dc7900 speaker 300 wide.jpgThe HP monitor stand is nice, certainly nicer than Dell’s. The dc7900 did not come with an internal speaker, but given the size of the speaker (my first machine has one) I doubt it’s good for much more than beeps. And if I ever want one, I can get a NOS unit on eBay for $5. (The Dell speakers for their USFF lines had built-in audio amps and much better fidelity.)

The system will replace an older Dell machine that Carol has been using for some time, with a slower processor and a maddeningly intermittent front panel that prevents her from plugging thumb drives into the front of the box. The machines are roughly the same size, but the Dell electronics have been twitchy, and the combo monitor stand horrendous. The old machine has external speakers, so the HP’s near-microscopic squeakplate won’t be an issue. The HP is newer, and the Dell cost me three times as much when I bought it five years ago.

Overall, a huge win!

Finally, seeing listings on eBay for sales lots of literally hundreds of used “cube machines” like the dc7900, I’ve begun to wonder if it’s the end of Owgust for the ordinary, non-gamer desktop PC industry. You don’t need a lot of crunch power for word processing, spreadsheets, local databases, or (most of) the Web. Even with only 4GB installed, I streamed a whole movie on the first dc7900 without a glitch. So these machines are perfectly usable for ordinary people doing ordinary computer-y things. You can spend $500+ for a desktop box at Best Buy…or you can get the whole damned system from eBay for $90, delivered. They’re not new. But they’re clean, small, and rugged. Parts are available on eBay, from the crappy little microspeaker up to whole motherboards–though at these prices, I consider the machines disposable and won’t be replacing any misbehaving mobos.

A lot of desktops are being replaced by laptops, which is really where the action is these days, as well as the high prices manufacturers prefer to get. If you’re going to stick with a boring desktop PC, you might as well get one used for 75% (or more) off retail. I’ve got a big hulking custom Core I5-2400 quad, which I’ve used since 2012, and it’s still more than fast enough for my needs. Furthermore, it’s in a Thermaltake V9 Blacx case with SATA sockets on the top panel for backup drives. Damned useful. I could get a faster mobo for it, but…why?

This all reminds me of a Contra entry I posted back in 2009, about how with cars (and silverware) lasting a lot longer than in years past, we need to manufacture fewer cars and less silverware to avoid saturating the market. The same goes for PCs. As each wave of compact cubicle machines comes off depreciation and heads for eBay, the price of a perfectly usable desktop machine goes down. Even if the $65 deal I got last week was unusual, it won’t be for long. Keep your eyes open.

Cheap Machines: The HP/Compaq dc7900

Front View On Steampunk Table - 500 Wide.jpg

Back in the early oughts, I saw my first ultra-small form factor (USFF) PCs at our doctor’s office. The machines were Dell Optiplex SX270s, and they were little marvels: Quiet, fast, easy to field-strip and very reliable. (There was a certain widespread problem with bad electrolytic capacitors in that era, and I ran into a couple of SX270s and Samsung monitors containing said bad caps.) They were P4s running XP, and Carol used one successfully as her main machine for a number of years. We donated several to our church’s office, which was pretty full and rather tight, space-wise. Nobody had any trouble with them. Even in 2007, they could be had for $200 or less, depending on what they had in them in terms of RAM and HD.

The SX270s were 2001-era machines, and I’ve long since gotten rid of them. I had a couple of slightly later models, including the SX280 and GX620. I took the 620 to the Taos Toolbox SF workshop in the summer of 2011, along with my steampunk computer table and my Aethernet Concentrator, as Jim Strickland dubbed it. It mounted behind the monitor, and while that made it a little tricky to plug in thumb drives, it made very good use of what small space the table offered.

The steampunk computer table is still in my office, and if I ever go to another live-in workshop again, I’ll take it with me. The GX620 ran Win7 badly, and has been gone for several years now. I need a newer machine to go on the table. Notice I didn’t say a “new” machine. In fact, I was a little curious as to how cheap a machine I could get on eBay that would do the job (office apps) and mount to the dual arm monitor stand that I have clamped to the table. That meant a machine with VESA holes, ideally. Such exist; I had seen them years ago.

It didn’t take long to find such a machine: The HP/Compaq dc7900 USFF. At 10″ X 10″ X 2.75″ it’s a little smaller than the SX270. And the price, hokey smoke! I bought one for $37. Now, that didn’t include a hard drive, but I have a box full of empty SATA hard drives. It came with a DVD-RW drive (and LightScribe, at that, heh) 4GB RAM, and an outboard 135W power supply. The CPU is a 2.5 GHz dual-core Pentium E5200.

Cropped Front View dc7900 - 500 Wide.jpg

I installed Win7 on it, and boom! It just worked. It identified the Dell E228WFP monitor I had attached to the monitor stand and adjusted its resolution to match. I installed enough software to test it but no more than that; like I said, I don’t need it right now and it was mostly a research project and a bit of a stunt, to see how much machine I could buy online for how little money.

Below is a side view of the setup. I used four M4-10 screws to mount it to the monitor stand (VESA is a metric standard) and twisted the arm around until the dc7900 was level with the top edge of the monitor.

Side View - 500 Wide.jpg

Internally, the machine is uncrowded, with two small and almost silent fans to pull air past the CPU heatsink and out of the machine generally. It has eight USB ports, plus both PS/2 keyboard and mouse DIN connectors.

Interior Closeup - 500 wide.jpg

The hard drive is mounted underneath the optical drive, but both come out very quickly without any screwdriver involvement. The hard drive is screwed into a little spring-loaded caddy that snaps into place and mates the SATA connectors firmly, with a little constant spring pressure to keep the drive from walking out of electrical connection.

I’ve only been messing with it for a few days, but so far it’s been trouble-free and able to do anything I could throw at it. No, it’s not as fast as my quadcore. I won’t be doing any gaming or video editing on it. Word processing and email don’t take a lot of cycles. Web browsers are wildcards in that regard, but so far it’s been able to render YouTube videos without any stutter or artifacts.

If you need a physically small machine for ordinary office work, I recommend it. And hey, for $37 plus a junkbox SATA HDD and an OEM copy of Win7, I’d say it’s hard to beat.

Egg++ and My USB Microscope

Something a little peculiar happened this morning. I cracked an egg into a (white) bowl for scrambling, and the albumen looked a little pink rather than clear. Blood, fersure, though I already knew (I don’t know why) that blood in an egg doesn’t necessarily mean that the egg was fertilized. However…next to the yolk was a little brown thing about 3/8″ long. It was about the right shape for an embryo, but it was too small to pick out any details. So…

…I cranked up my new USB microscope, which I got from Carol for my 65th birthday this summer. Worked like a champ:

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I’m no expert in chicken embryology, so this is still a guess, but I’ve never seen anything like it in an egg before. The pink in the albumen suggests blood, after all.

Here’s the setup I used to take the photo, which will show you the microscope and its focusing stage:

microscope-500 wide.jpg

Like any reasonable optical microscope (we have one from Carol’s college years in biology) it has a coarse focus (the knurled column attached to the metal base) and a fine focus on the end of the camera tube itself. It plugs into any USB port and draws whatever power it needs from the port.

The device shown above costs $77.95 from Amazon.

If you don’t think squicky blobby things do the instrument justice, here’s something on the hardware side. This is a surface-mount LM386 audio amp, measuring just a hair over 3/16″ long:

LM386SM0002.jpg

The imaging software I’m using (free) is called MiniSee, and it works tolerably well. Other packages exist, and as time allows I’m going to try them.

The real challenge with the microscope is lighting. Lighting makes a huge difference in the quality of the image coming in from the sensor. There are eight white LEDs in a circle around the sensor, with a brightness control built into the USB cable. These work well for looking into dark places (like the back of my mouth) but don’t do well with objects lying on the metal stage. A flat black background is useful, especially for metallic objects. I intuit that some sort of small gooseneck desk lamp would do the trick, and I’m looking.

The instrument comes with a number of plastic probe tips for looking at your ear canal, up your nose, and, well, where the sun don’t shine. The mini-CD wouldn’t spin up on my quadcore, and as it turns out I didn’t need it, given MiniSee. (One of the reviewers on Amazon claims it’s all in Chinese, anyway.)

Overall, I’m more than pleased, especially for something in the $75 price class. There may be better ones. I see quite a few on Amazon. But this one will do.

Oh…I scrambled the egg and ate it, once I picked out the embryo. What’s a little chicken blood when dinner generally hits the table medium-rare and still dripping?

The Other Fry’s

Sure, you’ve got Amazon Prime. (I do too.) But I have something that (most of) you don’t have: Fry’s Electronics. It’s a 12-mile drive from here, so I can’t just dash over anytime I want, like I can to Artie’s Ace Hardware. However, I realized after stopping in after a 15-year hiatus the other day that I need to go there more often.

Fry’s is hard to describe. It’s a double-big box store, done up in Aztec decor to look something like a pyramidal temple. It’s the ultimate nerd supply house, and has everything you might expect: motherboards, memory sticks, power supplies, cases, monitors, hard drives, Flash drives, software, and so on. Want to build your own desktop? It’s all there. However, Fry’s is remarkable for going even deeper into the wild country of the word “electronics,” right down to resistors and capacitors, soldering stations, shrink tubing and wire in any color you could name, and aluminum chassis. Good lord, they even have panel meters. Tools, wow: multitesters of every sort, needle-nose pliers, dykes (sorry; I still call them that), Dremels, Internet cable connector crimpers, and on for page upon page.

It gets a little nuts after that: toys, kites, CDs, DVDs, candy, all kinds of snacks, light bulbs, night lights, swamp coolers, refrigerators, camping gear, CB radios (!!), and fifteen varieties of fidget spinner. There was a display of something I truly don’t understand: body shapers (which is I think the generic term for things like Spanx) printed to look like bluejeans. Yes, I know, there are plenty of women nerds…but underwear in a resistor shop?

Crazy world.

Why was I there? I’ve noticed over the past year that the Mozilla codebase has grown ever more memory-hungry. Waterfox has taken to gagging with just six or seven tabs open. I’ve been meaning to add more RAM to my quadcore for some time, on general principles. It started out as an XP machine, and so had a scant 4 GB since I bought it. Now I had an excuse. Windows 7 Pro 64-bit can manage 192 GB of RAM, so throwing 16 GB at it is no big deal. But since I dropped those sticks into the quad, I haven’t heard the least little feep out of Waterfox.

Excellent prices, overwhelming selection, and people in the aisles who know what they’re talking about. Still another expression of the boggling richness of Phoenix’s retail sector. Fry’s Electronics is legally unrelated to Fry’s supermarkets, but was created by the sons of the man who founded the supermarket chain. If you’re ever in town for some reason, make sure you go over there. If you do, call me and I’ll come along.

Buy some hot pink shrink tubing. Dare ya!

Odd Lots

  • Solar cycle 24 is crashing, and we’re still three years from Solar minimum. 24 really does look to be the weakest cycle in 100 years or more.
  • And if you don’t think the Sun influences Earth’s climate, read this, about the Sun’s indirect effects on climate and why they make climate so hard to predict.
  • I doubt the payback would be more than the cost of the equipment and the electricity, but you can mine bitcoin with a Raspberry Pi–or better yet, a whole farm of them. (Run them from a solar panel?)
  • Speaking of the RPi: I burned a new NOOBS micro-SD last week, and used it to install the latest stock Raspbian. What I discovered is that this latest release has a terrible time detecting any monitor that isn’t straight HDMI. I’ve been using the RPi with older 4:3 DVI monitors through an adapter cable ever since I got my first board, and the board had no trouble figuring out the size of the raster. I’ve screwed around with the config file with only partial success; even telling the board precisely what mode your monitor speaks (1600 X 1200, 75 Hz) doesn’t guarantee correct video.
  • When I was much younger I wanted a PDP-8. And then a PDP-11, which I almost got because Heathkit actually made a hobbyist PDP-11 desktop. I settled for an S-100 8080, because there was actually software for it. I recently stumbled on a hobbyist PDP-8 system based on Intersil’s IM6120 chip. It’s not hardware you can buy; you download the PCB design and the software, get somebody to make the board (not hard these days) and then stuff it yourself. Runs FOCAL-69 and OS/8. Paleocomputing at its best!
  • From the It’s-Dead-But-the-Corpse-Is-Still-Twitching Department: Aetna is pulling out of the Obamcare exchanges entirely next year, citing $200M in losses.
  • You won’t believe where Earth’s atmospheric xenon comes from! (Actually, you will…but you have to say that these days because clicks.)
  • Excellent long-form piece on why we should fear an ideologically uniform elite. From the article: “If you really want to live in a world without tyranny, spend less time trying to show others why you are right and more time trying to show yourself why you are wrong.” Bingo. Because no matter what you think, you are always wrong. About everything. Nothing is simple. Nobody has the whole story. Ambiguity is everywhere. Certainty is poison.
  • How many times do we have to say this? Eat fat to lose weight.
  • We could use more research here (can’t we always?) but it’s certainly possible: Eating more salt may help you lose weight. Could be; I determined by experiment that salt doesn’t affect my blood pressure, so it couldn’t hurt to try.
  • A correlation has been found between consuming lowfat or nonfat dairy products and Parkinson’s disease. No such correlation is seen with full-fat dairy products. My guess: Your brain is mostly made of fat, and people who eat low-fat dairy tend to eat low-fat everything. So this is yet another reason to go low-carb high fat, even if you don’t need to lose weight. Fat is a necessary nutrient!
  • After decades of difficult research, scholars have finally decoded the lyrics to the “O Fortuna” movement of Carmina Burana. And…they aren’t in medieval Latin at all. (Thanks to Sarah Hoyt for the link.)

A Two-Arm Monitor Stand for the Raspberry Pi

Two Arm Mount on Steampunk Table-Cropped-500 Wide.jpg

If what I’ve heard is true, most Raspberry Pi installations consist of the naked circuit board lying atop a nest of wires on the desk behind a monitor. I think it’s true; that was certainly my Raspberry Pi installation for a long time. Now, I’ve decided to use my steampunk computer table as my Raspberry Pi 3 workstation. And I got an idea: Use one of those VESA-standard 2-arm monitor stands that clamps to the edge of a desk without any drilling into or other hacking-up of the desk. One arm holds the monitor, and the other holds the Raspberry Pi itself.

The trick is to buy one of several Raspberry Pi cases that includes a flange with VESA 75 or VESA 100 holes. VESA is a standard for TV and monitor mounting hardware. Its two smallest configurations are a 75mm square, and a 100mm square. Most modern flat-panel TVs and many monitors have threaded holes on their back faces arranged in one of the several VESA configurations. I’m pretty sure (having looked at a lot of monitors and TVs in the past few years) that the 100mm configuration is the commonest. It’s the one on the Dell 1907fp monitor that I’ve been using for Raspberry Pi boards since the beginning. VESA-compatible displays generally use metric screw threads in the mounting holes, with M4 the standard for the smaller configurations, including 100mm. M4 screws can be had at Ace Hardware, and probably also at Home Depot and Lowe’s. (I go to Ace first for such things.)

The Raspberry Pi case that I used is this one:

RPi VESA Case.jpg

It has four little wings with both the VESA 75 and VESA 100 holes. The holes in the wings aren’t threaded, and easily pass standard 8-32 machine screws, which I used to hold the case to the second arm of the monitor stand. I oriented the Raspberry Pi with its USB ports on top, so I can reach over the monitor and plug in peripherals or thumb drives easily.

This approach isn’t limited to the Raspberry Pi. There are VESA cases for the Intel NUC (Next Unit of Computing) boards, and most of the higher-end embedded boards like BeagleBone. On a small table like the one I made, there’s not a lot of flat space to park a case of any size, so whatever computer I’m going to be using on it should be able to hang on that second monitor arm. The arms on the unit I bought can hold up to 12 pounds each. Most of the small-form factor Dell machines I use are that weight or lighter. Dell’s Micro 3000 series has an optional VESA bracket, and brackets for other models may be available. And hey, you guys could rig something, right?

Odd Lots