Category: Tech/Geek

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USB charging for the RV-12

I decided that the only thing I would ever use the 12V power point in my RV-12 for would be to plug in USB power supplies.  So, I figured, why not bypass the middleman and just install a USB charging plug?

It’s trivially easy to find a dual-outlet USB charging jack with the same form factor as the Van’s supplied 12V outlet.  The only downside I could find was a constant 10-15 mA current draw.  The USB power point is a switching regulator and an LED.  Even after clipping one lead to the LED it still draws about 10 mA.  Now, normally the 12V power point is wired directly to the battery positive terminal with an in-line fuse holder.  It would probably take a long time for that 10-15 mA drain to make a real impact on the capacity of the PC680 battery in the RV-12.  It would only be a factor if the battery were weak anyway — precisely when you don’t want any excess drain.  Plus, the old repair guy in me just doesn’t like the idea of cheaply produced electronics left under power all the time, unattended in an airplane parked in a hangar.  Just to be sure I could shut everything off, I moved the supply lead from the positive battery terminal to the switched side (inboard side) of the master contactor.  Now I have USB power controlled by the master switch.

It may be that at some point I will want to plug in something that requires 12 V – like a tire inflator, for example.  I plan to put some leads and small battery clamps on the old power point and keep it around just in case.

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ADS-B followup

Fun stuff…  so I’m playing around with several different aviation apps on my Android tablet, with a Stratux setup just sitting on the window sill of the spare bedroom where it can “see” enough GPS satellites to get a position fix.  I’ve got one SDR radio receiver on it, set up for 1090 MHz to catch transponders in passing aircraft.  I went in to plug the power in to charge the tablet — I’d left it in there overnight — and saw half a dozen targets displayed.  I zoomed in a little and there’s an American flight at 31,000… A Virgin flight headed for Newark…  Hey, wait a minute — one looks familiar!

Screenshot_2016-03-16-13-01-03

N151MH – a friend and fellow EAA Chapter 80 member, out in his ADS-B “out” equipped RV-12.  Absolutely beautiful day for it, too!  Have fun, Mike!

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Adding ADS-B IN

I really wanted to add ADS-B to the RV-12, for some pretty obvious reasons.  Getting weather and traffic data for improved situational awareness seems like a really good idea.  I’m also not thrilled with the tiny buttons and small screen of the Garmin 496 currently mounted in the panel.  So, I started looking at various alternatives for ADS-B IN.  I figured I had several choices…

  1. Do nothing.  No weather, no traffic, no expense.  Punch flight plans into the Garmin 496 by hand, let that drive the autopilot.  It’s not the worst fate, but there are better ideas.  Cost: None.  Benefit: None.
  2. Pay a ridiculous amount monthly for XM WX, still get no traffic.  No freakin’ way.  Cost: High (several hundred per year).  Benefit: Very low.
  3. Replace the Garmin 496 with a 696 and GDL-39.  I was almost there.  I bought and repaired a used 696 and it’s very nice.  The GDL-39 is not cheap, but I’d have traffic and WX.  Flight planning is easier, but the maps need updating ($$).  Plus it would take MAJOR surgery on the panel — like rip everything out, rearrange it all and rebuild the entire panel with everything custom.  Cost: Mid-high, even after selling the 496 (it’s a little scuffed and gouged on the edges).  Benefit: Mid-high.
  4. Foreflight running on an iPad Mini, with Stratux.  It’s almost a perfect solution…  but it won’t drive the autopilot, which means I’d have to enter the flight plan twice (once in FF, once on the 496) and any enroute changes would need to be done in two places to keep the AP on course.  Foreflight would require an annual expense, though it’s not too bad.  And of course iPad Minis are not cheap.  Cost: High.  Benefit: High.
  5. Avare running on a Galaxy Tab S2 8″, with Stratux.  Avare is completely free including charts, maps, approach plated, A/FD, all of it.  It’s not QUITE as nice or as smooth as ForeFlight, but fairly close.  And it will drive the autopilot with a bluetooth-serial converter, which FF cannot do.  I can keep the 496 in the panel as a backup just in case.  Cost: Medium.  Benefit: High.

I seriously considered 3 through 5.  If I’d been able to figure out how to reduce the amount of panel rework for the 696, or if the cost of the GDL39 wasn’t so high ($400+ used) I’d have probably done that.  As it is, I picked up a used 696 cheap, repaired the battery connector, and will sell it — probably for enough profit to pay for the Galaxy Tab.  That would make my total ADS-B/EFB setup cost under $200, even after mounting good antennas on the plane.

 

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Sorry, I don’t read Chinese…

For the past several weeks I’ve been getting a fairly large amount of Chinese language spam leaking through. Since nearly all of the data (From:, subject, etc) are Chinese characters, my regular Postfix spam filters have not been effective in eliminating it. I finally got tired enough of it to do a little Googling. It’s trivially simple to just reject any incoming email with Chinese characters in the subject line:


/^Subject:.*=\?GB2312\?/ REJECT Sorry, this looks like SPAM (C1).
/^Subject:.*=\?GBK\?/ REJECT Sorry, this looks like SPAM (C2).
/^Subject:.*=\?GB18030\?/ REJECT Sorry, this looks like SPAM (C3).
/^Subject:.*=\?utf-8\?B\?[456]/ REJECT Sorry, this looks like SPAM (C4).

I made the change last night, and this morning came in to find no Chinese spam and several rejects in the mail log… all from pretty obvious spam sources, like this one:

Jul 6 01:12:51 newman postfix/cleanup[30385]: 99EB31A6D3: reject: header Subject: =?utf-8?B?44CQ5Lqk6YCa6ZO26KGM5L+h55So5Y2h5Lit5b+D44CR5bCK6LS155qEZGFpbmlz?=??=?utf-8?B?6I635b6XMTAw5YWD57qi5YyF5aSn56S85rS75Yqo6LWE5qC877yM6aKG5Yiw5bCx5piv6LWa?=??=?utf-8?B?5Yiw?= from spamtitan2.hadara.ps[217.66.226.109]; from=<wkh@p-i-s.com> to=<dale@botkin.org> proto=ESMTP helo=<spamtitan2.hadara.ps>: 5.7.1 Sorry, this looks like SPAM (C4).
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How much is your time worth?

Lord, I hear this question so often as justification for an overpriced widget or service.  Apparently some people think one should spend any amount of money to avoid doing a few hours’ worth of work.

The latest example is a neat little box for use on experimental aircraft.  It replaces the traditional master battery and starter contactors, as well as a current measuring shunt and maybe a fuse or two.  I think there may even be a diode or two thrown in for good measure.  It would simplify the wiring on the firewall side of an experimental plane, sure.  It might even shave one or two nights off of your build time.  Maybe.  You’ll still need to do some wiring, and of course there’s a nice canon plug on the back side, so you’ll still need a crimp tool and it’ll need to be connected to various switches and stuff on the panel.  All in all, I’d say it would be a nice little $200-$300 box.

The problem is, they’re apparently going to want about $1200 for  it.  Say what?  that’s about $1050 or $1100 more than I’d spend on the parts to do the job the old fashioned way.  On one of the very few online forums I use any more, there is a little bit of discussion about it.  And just as sure as Godwin’s Law it’s only a matter of time before someone chimes in with, “How much is your time worth?” – as if that justifies any expenditure, no matter how ridiculous.

Well, I’ll tell you.  For one thing, my “internal billing rate” — how much time I’m willing to expend to avoid an expense, or conversely how much money I’m willing to spend to avoid work — varies greatly with how much I enjoy or do not enjoy the work to be avoided.  Self-surgery?  Yeah, sure, I’ll pay a professional to avoid doing that work.  Mowing the lawn?  It better be cheap, I’m not shelling out $40 a pop for that.  Wiring work on an airplane I’m building?  Well, let’s just say $1200 will buy an awful lot of hours.  I figure it will probably take about 2 evenings of work — let’s be really generous and call it six hours — to do that wiring, of which maybe half would be saved using the new whiz-bang box.  So that works out to – oh, let’s see, carry the one…  roughly $350 an hour, and if the bloody thing ever breaks I have a plane out of commission for God only knows how long, versus a trip to Auto Zone for parts.  I don’t know how long they will be manufacturing and supporting these, but I’ll bet my airplane is flying for longer than that…  meaning that some day this thing is almost certainly going to cause a time consuming and expensive problem.  Hmm, there goes all that time we “saved” on the front end.

I’m sure they’ll get some customers, but I’m afraid I won’t be one of them.  And I won’t even feel like a tightwad.

 

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Various stuff…

First of all, sue me…  I’m loving the iPhone.  I never thought I would.  There are a few little annoyances, but overall it’s a great little widget.

Went to the Ak ARC flea market Saturday.  I had a table to sell kits, but I don’t know why I bothered.  I did (just barely, maybe) cover my breakfast, the table and my gas to drive there and back, so I guess it was OK.  Honestly, I think most of the stuff for sale was the same crap I’d seen last year.  There was, however, a table set up by the Omaha Maker group, and separately a ham had a 3D printer running printing out something or other, I never did figure out what.  So why did I go?  It was good to see and talk to some of the hams I only see once in a while.  Jack WA0SAQ was there, Dave WJ0Z and some others I seem to only see once every year or five.

I did some CNC engraving on the end panels for a new flavor of PicoKeyer.  I think it turned out pretty well.  It will be a little extra work — OK, a lot of extra work, but I think it will be worth it.  This will also probably be the motivation I need to finally break down and make a better fixture for the end panels I use for the boxes.  Maybe something I don’t have to stand there and hold each one in place.  It would be a worth a lot to me to be able to not stand there the whole time the mill is running, holding parts and trying to avoid getting an end mill through a thumbnail.  McMaster, here comes an order!

And…  some days I miss not having something that looks like airplane parts in the garage.  In a couple of weeks, though, I should have a “canoe” going and by Spring it should be looking airplane-y again.

That is all.

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Technical stupidity.

It baffles me how people let their stuff get so messed up, and how companies will go so far out of their way to NOT be there for customers.

I got a phishing scam email supposedly from First National, where we used to have accounts.  Being the nice guy that I am, I figured I’d let them know the specifics.  After all, some people are dumb enough to fall for stuff like this.  A fake “IRS agent” almost managed to convince my 88-year-old mother to wire a few thousand dollars to avoid going to jail — never mind that she doesn’t owe the IRS a penny, never has and has never tried to cheat on her taxes.

Well, of course the only way to contact FNBO or FNNI is via a web form.  So I spend several minutes sending detailed information to them — the target web link, the email header, etc.  Then I hit the “Submit” button…

And got an error message.

Screw ’em.

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Into the dark side. Or whatever.

apple-logoMy Droid 3 has been giving me fits for a while.  The phone itself is fine…  there doesn’t seem to be a hardware problem.  A couple of months ago, though, it started nagging me daily to install a slew of app updates, including “Google Play Services”.  Half the apps I use regularly finally refused to run at all until I installed Google Play, which I resisted because it wanted access to everything on my phone.  All data, all history, location, email, everything.  I finally had no choice but to dump the phone or install the damn thing, so I installed it (and the subsequent dozen or so other app updates).  Since that time the phone has been plagued with odd behavior.  It will periodically freeze up, require reboots, not be able to place a call for several minutes after a restart, and I’ve had to pull the back off and remove the battery a couple of times when it froze up and started getting uncomfortably hot.

My employer offers me the option of having a corporate owned cell phone.  We’ve currently got a choice between Blackberry and iPhone.  I can understand their refusal to allow Android phones to connect to the corporate network — the ease with which an Android can be rooted and bent to the owner’s will is great for experimenters, developer and hackers (a term used in the proper, good sense here) – but it also removes any surety that an app can actually be trusted.  Anyway, the Blackberry phones are locked down tight and everything (web, email, etc) goes through the corporate proxies.  The iPhone situation is different; there’s a secure VPN app that handles all the corporate traffic, but outside of that app web browsing and email don’t pass through company servers.

I opted for the iPhone, so as of yesterday afternoon I have a shiny new iPhone 5S.  It is, I believe, the first Apple product I have ever owned, aside from a garage full of Lisas that passed through my hands back in the late 1990s. I have not used any Apple products for more than a few minutes since the Apple ][e.  No iPod, iPad, iPhone, Macs, iMacs, nuthin’ more than a passing familiarity.

So far I’m impressed.  The phone itself is a thing of beauty, which is to be expected of any new cell phone.  The Samsung Galaxy S III that Lisa carries (and the IV and V, I assume) are nice too.  So no big surprise there.  The thing is quite responsive, and almost everything is simple and intuitive.  I especially like being able to uninstall an app without having to wade through setup menus to do it, and the ability to effortlessly pull up the flashlight, timer, camera and calculator without even unlocking the phone — very nice.  It will even show me text messages and the first couple lines of new emails without unlocking the screen.

There are several areas in which iOS seems to really outshine Android OS.  The email client is a bit nicer than any I have used on the Droid.  iBooks has far and away the best PDF reader I have used on any platform.  The voicemail management is so well integrated with Verizon voicemail that I honestly didn’t realize it was there at first.  I see that there is a built-in flashlight app (lacking on the Droids) and timer/stopwatch.  The camera and its app is much better than anything I have seen on a phone before.  Overall, the UI seems a little smoother, a little quicker, a little more intuitive.  I can see why people rave about their iThingies.  And Siri works pretty well.  I even like the Lightning connector, though the cable they included could have stood to be about a foot longer — easily and cheaply remedied on Fleabay.  And while more of a hardware thing, the fingerprint scanning button is slick as all hell.

A few areas could use improvement.  For one, I do miss the “back” button.  I really do.  I get the whole single-button idea, but I’m constantly reaching for the back button.  A nightstand/dock mode like my Droid has would be awfully nice (maybe I just haven’t found it yet).  And for the love of all that’s good in the world, why can’t I just drag and drop files from my PC??  Using iTunes to copy PDFs to the phone is just plain stupid.

Anyway, the message here is really twofold.  First, kudos to Apple — the iPhone is really, really nice.  I don’t know that I would ever have bought one if I had to spend my own money on it, but it’s nice.  Second, shame on Google.  It took a lot to drive me away from Android, a platform I loved for what it was and what it represented.  They just couldn’t leave well enough alone.  They have managed to make it so intrusive and so inhospitable that even I had to walk away in disgust.

Now, about that Macbook Air…  hmmm.

 

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Halt and Catch Fire premier

Last night I watched the first episode of Halt and Catch Fire on AMC.  I wanted to love it, was tempted to hate it, and in the end opted for neither one.

For those of you who don’t know me, I lived through the period in question, and in the same industry…  although not working for TI, or a fictitious Texas OS vendor, or even directly in the PC end of things.  Still, those were some pretty exciting times.  I was fixing mainframes for a living, but lived and breathed microcomputers every day.  When micros first came on the scene (we didn’t call them “PCs” until well into the 80s), it was like the Wild West, in all the good ways.  There was opportunity around every corner.  I would be hard pressed to count the number of companies making computers in the pre-IBM days; some very cool things were being done by a lot of gifted and smart people.  I remember one in particular, a machine made by Ohio Scientific that had multiple processors (6800, 6502 and Z-80 if I remember right) and could boot different operating systems depending on your mood.

Anyway, the first bit of bad news came during the opening scene — a typed-text description of the “HALT AND CATCH FIRE” machine instruction.  It’s a simple concept, easy to explain and even a little humorous.  And they got it completely wrong.  Stupidly wrong, in fact.  I felt like a doctor watching Gray’s Anatomy or a cop watching Blue Bloods.  Sigh…

It got a little better from there, but there was some really stupid technical nonsense thrown in for no good reason.  Something real and believable would have been just as dramatic, or maybe even better.  You can’t cut a soda can in half with a pencil soldering iron  – and why would you need to to fix a Speak & Spell?  I especially loved the scene where he’s tediously de-soldering connections on the back of the circuit board — then triumphantly extracts the chip FROM ITS SOCKET.  And then of course there is the biggest non sequitur: ALL of the IBM Personal Computer’s schematics as well as the complete assembler listings for the BIOS were readily available from IBM, in the IBM Model 5150 Personal Computer maintenance manuals that anyone could buy.

So building a clone of the IBM PC was really pretty trivial from an engineering standpoint, and other manufacturers jumped in early and often.  Most tried to build better machines that ran their own version of MS-DOS, and most used the same bus so that expansion cards were interchangeable.  It took a while for the tyranny of the marketplace to grind everyone into making exact clones of the IBM machine, other than some speed improvements and of course much lower prices.

The list of ridiculously stupid technical gaffes is pretty impressive.  The scene where they start reading out the BIOS?  Well, first off, there were no white LEDs in 1983.  You could have any color of LED you wanted as long as it was red, green or yellow.  And binary 1101 is a hexidecimal D, not B.  PC motherboards don’t arc and spark, and if one did it would be dead, dead, dead.  His oscilloscope was displaying a stupidly Hollywood-ized pattern, and why would they need to use one  anyway?  Could they not read the pinout from a common EPROM data sheet?  He’d just finished explaining how all the parts were off the shelf common stuff.  And why would such a hotshot engineer not rig up an interface to his TRS-80 to read out the BIOS chip?  For that matter…  why not just type in a few lines of BASIC program to read out the BIOS and save it to disk, print it or display it on screen?

From a technical standpoint the show is senselessly over-dramatized in ways that really spoil a lot of the “geek appeal”.  If you know much at all about the technical matter at hand you’ll spend half your time shaking your head and saying, “Wha??  No…”  They did, however, seem to do a fairly decent job of catching the general tone of the period, and the story line (other than the glaring issue of the whole made-up BIOS thing) has potential.  I just wish they’d have hired an actual technical consultant, or listened to him if they did hire one.

 

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Improving the Neato vacuum

If you have a Neato XV series robotic vacuum, and you don’t already have one, you need to switch to the curved/spiral brush.  This is the one Neato ships with the “pet” versions of the vacuum.  It’s far quieter than the one with the parallel straight rubber blades.  The sound of the vacuum is reduced from a dull roar to a far less intrusive sound.  I can barely hear it when the vacuum is running downstairs and I’m in my office.  I’ve also noticed that it also seems to pick up a lot more dust and debris.  Overall it’s a huge improvement.

I ordered mine from Crucial Vacuum, part number 945-0002.  Best 25 bucks you can spend on your little robot friend.