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hardware

A Two-Arm Monitor Stand for the Raspberry Pi

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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

Odd Lots

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LED Bulbs, RF Noise, and a Crazy Idea

Carol and I were in Costco last week, stocking up on consumables (everything from toilet paper to Hoody’s Peanuts) when we spotted something that made me do a double-take: a package of four Feit LED dimmable 60W equivalent light bulbs for $10. I’ve never seen them for less than twice that. We grabbed a pack to try at home, because our new house here contains a lot of 60W bulbs.

How much of a lot? There are nine Hampton Bay ceiling fan/lamp fixtures, each holding three 60W bulbs. (We found later that the fixture over the dining room table had three 75s in it.) That’s 27 bulbs right there, plus another twelve or fifteen in bathrooms and outside light fixtures. Figuring 40 60W bulbs, that’s 2,400 watts. Granted, not all of them are on at once, and several fixtures (like the one in the guest room and the two outside on the patio) are rarely on at all. However, there are another eighteen 65W ceiling floods, so I’m guessing our typical evening use is about 2,500 watts overall. It adds up. If bulbs are now as cheap as Costco was offering them, I was ready to jump.

A sidenote: There was some sort of utility company instant rebate, so the register price was about 1/3 less than the package price. Outside the Phoenix area, your prices may (and almost certainly will) vary.

This being Arizona, there was a thick layer of brown dust (over and above the dead bugs) on the lamp globes and on the existing bulbs themselves. We ran three loads of lamp globes through the dishwasher because their spatter finish tears threads off the ScotchBrite pad by the sink. I put three bulbs in the fixture in Carol’s office, then stood back to gauge the quality of the light.

Marvelous! Three $2.50 LED bulbs gave brighter and slightly whiter light for a total power draw of 28.5 watts. We went back to Costco and bought 24 more, plus a test pack of 65W equivalent LED ceiling floods. I spent a day on a ladder swapping out bulbs, and although the ceiling floods aren’t all done yet, we’re looking to cut our lighting power draw to 1/6 of what it would be on incandescents.

This isn’t all about money. It gets hot in Phoenix in the summer (duhh!) and the heat that you pay for when you light your bulbs you then have to pay to pump out of your house with the AC. Ok, so maybe it is all about money. In some respects, LED bulbs are a twofer.

Now, there’s a downside. Both CFL and LED bulbs require power at entirely different voltages than incandescent lamps. Every bulb has a little power supply in it, and to keep the power supply circuitry small, the supply uses a technology that generates a lot of RF noise. If the whole house is running LED bulbs, I’m guessing that my IC736 will deliver audio that sounds like the center of a raging thunderstorm, only 24/7. I don’t have my shack wired up yet, but it’ll be interesting to see what happens when I run a temporary longwire out to the pool shed later this year.

Now, it won’t happen this year and perhaps not next year, but the 5-year plan includes a new building in the NW corner of our 5/8 acre lot to house my workshop and radio shack. (I’m using the small garage for now, and although I was clever and got everything in, it’s…cramped.) I’m sure I’ll hear our LED bulb symphony (and perhaps the neighbors’) but if I don’t use LEDs or CFLs in the shack, things may be a lot better.

So…what are the chances of opening up the bulbs, pulling out or bypassing the power supplies, and running them at the LEDs’ native voltage? This isn’t an idea original with me, and in fact one chap has a very nice article up on Instructables. The 40W bulb he dissected delivers 30VDC to its LED array, and he had to do some major surgery to rewire the array to take 12VDC instead. My approach would be to figure out what DC voltage a given type of bulb generates for its LEDs, and then build a high-current passive (i.e., non-switching) power supply to deliver exactly that voltage to all the modded bulbs in the building. (Note that there’s nothing magical or standard about his 30V figure. That’s just what the maufacturer happened to use in that particular model of bulb.) This would require running a separate 30VDC (or whatever) power network inside the workshop building, but since it’s going to be a custom building, I can do that.

We’re not nearly done with the house and landscaping here yet, and I won’t have a great deal of loose time until the summer. (We still have work to do on our Colorado house before we sell it.) I’ll start a research binder on LED bulbs in the meantime, and maybe allow myself a few hours at some point to pull a cheap bulb apart to see what its LEDs are eating. If any of you have played around with LED bulb internals, (or have come across any pertinent links) by all means share in the comments. I have a hunch that a lot of very clever guys are pondering this problem right now, and I’m looking forward to hacking the hardware myself. I haven’t done much building in the last couple of years for various reasons, and damn, I miss it!

Odd Notes on the Samsung Galaxy Note 4

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Way back in my entry for November 24, 2015, I explained how we lucked into a pair of Samsung’s Galaxy Note 4 smartphones. The Note 5 was out by then, but I didn’t want it. Why? It has a non-replaceable battery and no internal card slot. That was a deal-killer for me, and something I’ll go into more detail on a little later. We stayed with Verizon, because several people said Verizon has the best local network in Phoenix. (I’ll state from experience that they did not have the best local network in Colorado Springs.)

Why did we want a Note phone at all? I have a lot of Samsung gear, and for the most part it’s been reliable and delivers what was promised of it. The Note 4 is bigger than my 2011-era Droid X2 (a feature I wanted, irrespective of the ghastly coinage “phablet”) but still small enough to fit in my shirt pocket. (I made scale cardboard cutouts of all the major phones I was considering and did the test on several shirts.) More compute power was basically assumed, since my Droid was almost five years old. I wanted a larger, brighter, higher-res display. I wanted S-Health, a piece of Samsung software that does several useful things, like tracking steps and measuring blood oxygen. Carol wanted a stylus. Her fingers have a somewhat strained relationship with touchscreens, and unlike me, she texts a lot. The stylus works perfectly for her.

I didn’t really intend for this to be a review, because by this time I’m guessing it’s pretty hard to find anybody selling Note 4s. Several people have asked me what I think of it, and what I’m doing here is gathering my thoughts on its first ten or twelve weeks in my pocket.

I like the phone a lot, and most of that cooks down to one thing: It consolidates several functions into a single slab. Prior to getting the Note 4, I did most of my ebook reading on my Kindle Paperwhite, which is still a marvelous item. However, it’s another slab, and if I’m running around it has to be carried somewhere. I was poleaxed at how good the Note 4 display is for text, assuming you’re not out in the sun. It runs the Kindle app, and it’s in my pocket any time I’m awake. So if I need an e-reader to kill some time in an unexpectedly bad line at the Post Office, it’s always there. In the photo above we have, L-R, the Kindle Paperwhite, the Galaxy Note 4, and the Droid X2, all running the Kindle app. I still lean toward the Paperwhite when I’m sitting in my comfy chair at home, but the Note 4 comes very close to the same experience.

It has a surprisingly capable digital camera, which (given sufficient light) takes very good HD video. The pedometer/blood oxygen/heart rate monitor serve specific needs of mine right now. I’ve tested the phone performing those functions against other instruments I have at home, and it agrees with all of them. I actually measured out a two-mile walk on MapPoint and walked it with the Note 4 in my pocket and its pedometer feature active. It agreed with MapPoint on the distance to within a couple hundred feet. I’m guessing that GPS helps out a little, as S-Health makes no attempt to physically measure my stride.

On the downside, battery life is nowhere near as good as on the Droid X2. I suppose that’s reasonable, given the device’s greater compute power, but it is annoying. When I’m at home, I find myself plugging it into the charger no later than 3PM and sometimes sooner. I’m not entirely sure how well it would handle a full 14 hour day. When the battery falls below 40%, I simply stop using it. If I had to be away from a charger for over a day (unlikely but possible) I would carry an extra charged battery.

Which brings me to the second point of this entry: The mysterious disappearance of replaceable batteries and SD card slots in modern smartphones. I specifically wanted the Note 4 because the Note 5 has no SD slot, and a non-replaceable battery that limits the useful life of the phone to the life of a single battery. Some say it’s a cost issue, which is nonsense, especially on a $500 high-end phone. Some say it’s a security issue, which puzzles me, since the phone can be set not to deal with apps installed on an SD card. No, these are excuses. I am pretty damned certain that the carriers are putting enormous pressure on the manufacturers (who sell most of their phones through carrier upgrades) to get rid of the card slots. The reason is simple: The carriers want to charge you bigtime for network data, and if you can sideload all your music and movies onto a 128 GB SD card, they won’t get paid when you don’t have to pull them down from the cloud. The battery is collateral damage, because the best excuse for a missing SD slot is to give the phone a back that can’t be removed.

Planned obsolescence is a particular loathing of mine. When I like a piece of gear, I want to be able to use it as long as I choose. (We drove our 1995 Plymouth Voyager for almost 20 years. We’ve had our 4Runner for 15 years now, and intend to go for 20 there as well.) Microsoft’s enormously pesty Windows 10 upgrade offer falls into that category. I like Win7, and feel that it’s by far the best version of Windows yet. I see no reason to stop using it. Sooner or later, MS is going to make the upgrade mandatory, or at least slip it in under the door in the middle of night, rather like Congress did with Obamacare. What happens then I don’t know and probably won’t talk about, except to say that I will keep on using Win7. Or perhaps switch to a Linux distro that’s been tweaked to look just like Win7. I have Zorin (if not the latest version) and may consider something like RoboLinux that runs Win7 in a VM. We’ll see.

Carol and I have now had enough experience with our phones to decide that we’re just not going to have a landline put in down here in Phoenix. We haven’t had one here for two months now, and haven’t missed it a bit. That’s a first for us: Neither of us has ever lived for more than a few days without a landline. (We also bought an indoor TV antenna and so far have not missed cable, either.)

The note 4 runs all the apps I’m used to running: Voice Search, Google Maps, Weather Underground, Sky Map, Waze, GPS Test, SoundHound, a couple of dumb puzzle games, and whatever else comes with the phone. Response is more than perky enough for my needs, which are nowhere near as smartphone-centric as a lot of people’s.

Bottom line: It’s a good phone. It can be loaded to the gills with Flash memory, and you can keep a spare battery in your pack. If you have one, take care of it, because given the carriers’ data-based business model, we may not see its like again.

Odd Lots

Odd Lots

Odd Lots

  • I posted The Cunning Blood on the Kindle Store 61 days ago, and in those two months it’s earned just a hair over $3,600. 46% of that came from KU page turns. Fellow indie authors, I think we have us a business model.
  • Tom Roderick sent me a link to a very nice graphical COSMAC ELF emulator, designed to look as much like Joe Weisbecker’s unit from Popular Electronics (August, 1976) as possible. You can toggle in opcodes like we did almost forty years ago, and run them. (The Q line drives an LED.)
  • In cleaning out the garage, I took a look at the motor/battery module of my robot Cosmo Klein (which I built in 1977-1978) and realized it wouldn’t take much to get it running again. The original Cosmo had two COSMAC systems and a glass-screen TV for a head (which made him very top-heavy) along with a cranky robotic arm. (Here are some photos of my COSMAC projects and Cosmo himself.) I could hide an RPi2 in that thing and you’d never find it. Funny how stuff changes in 38 years…or maybe not funny at all.
  • From Astounding Stories: Spacemen beating the crap out of one another in zero-G with…yardsticks. By Edmond Hamilton. Not sure of the year, but you can download the whole thing.
  • From the Weirdness-I-Just-Learned-About Department: The tontine, a financial arrangement in which a pool of people contributes equally to buy a pool of assets, and as they die, each deceased’s share is distributed to survivors. Apart from an inceptive to murder your tontine siblings, what could go wrong?
  • In the fever of a house hunt, I missed this item: Amazon is going to create its own line of house brands for food. I have a peculiar curiosity about house brands, which is a sort of shadow business that doesn’t get much press. Why would an industry-leader cereal manufacturer sell its cereal in bulk to other companies to sell as competing house brands? It happens, but nobody wants to talk about it. Big store chains have house brand versions of many products, including most mainstream cereals. There’s a book in this somewhere, though I don’t intend to write it.
  • If you’re not a balls-out supporter of nuclear power generation, I don’t want to hear a word out of you about global warming. We need base load, and neither Sun nor wind can provide base load. In truth, all that stands between us and a completely nuclear future is fear (i.e., political tribalism) and money. The money issue can be fixed. Alas, the gods themselves, etc.
  • It’s been 119 months since a major hurricane (Class 3 or higher) has hit the American mainland. Unless Joaquin goes ashore along the east coast somewhere in the next several days (and current winds argue against that) it’ll be 120 months–ten years–come October 24. That’s an all-time record since records have been kept. Global warming causes everything else; why not better weather?
  • And you wonder why I’m a global warming skeptic. Hey, fellow (potential) morlocks: I hear that our Educated Elite is delicious with melted butter.
  • Americans are embracing full-fat foods, thus spitting in the face of government advice. As well they should: The War on Fat is based on fraudulent science put forth by ace scientific con-man Ancel Keys, whose only real talent was getting government to take his side. Go butter, eggs, and meat. You’ll lose weight, and feel better.
  • Yes, I bring that up regularly, because I’m trying my best to ruin Keys’ reputation. His deadly advice has killed tens of millions, and is still killing them. “I’m supported by the government. I’m here to kill you.”
  • Some good news: A judge kneecapped champion patent troll eDekka by invalidating its only significant patent.
  • And more…for some people, least: Charlie Martin pointed me to an article from Harvard summarizing a study on the beneficial effects of coffee. Coffee appears to delay, improve, or prevent just about everything but insomnia. And what’s my main problem?
  • There! A month’s worth of grouchiness in one Odd Lots! (With a few other items thrown in for spice.) I don’t do that often, but it feels good when I do.

Odd Lots

Odd Lots