The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Author: Ed

  • Windows KB967715 Doesn’t Install: Fixed

    I fire up the Token Windows Laptop more or less monthly, to download data from our gaggle of Onset Computer Hobo dataloggers. As a result, the laptop gets broadsided with Windows updates from the Mother Ship and, although I look at ’em before installation to see wassup, I don’t really remember any particular update from month to month.

    It seems that, in order to solve the really-disable-Autorun-dammit problem, the patch described in KB967715 must update a registry entry that’s nailed down by some other program. As a result, the patch either doesn’t install, installs-but-fails-quietly, or installs-but-fails-loudly.

    It eventually percolated to the front of my dim consciousness that I’d seen all of those outcomes over the last few months…

    A bit of trawling turned up the usual collection of uninformed blather, plus what seems to be the Definitive Answer direct from the Mother Ship. Go there for the details.

    Update 967715 may be reoffered if the HonorAutorunSetting registry setting that is described in this article is not added to the registry hive. This issue may occur if some other program that is installed on the computer blocks the update from writing the registry entry. Such software may block the update during the installation of the update or may remove the registry entry after the computer is restarted.

    (“Registry hive”? WTF?)

    Basically, you download the patch as an executable file, save it somewhere convenient, reboot in Safe Mode (hold F8 down as Windows starts up, then pick Safe Mode from the menu), clickety-click on the patch program, and give it permission to have its way with your PC.

    So far, it’s all good. Maybe I won’t have to remember this for another month…

    Memo to Self: if all else fails, MS doesn’t charge for security-related patch assistance phone support.

  • Where To Put Too Many Clamps

    Clamp storage plates on floor joist
    Clamp storage plates on floor joist

    Not in a drawer, that’s for sure…

    Whack a narrow rectangle from some random scrap of thin wood-like substance, squirt hot-melt glue along one edge, stick it to the floor joist over your tool chest, align it pretty much horizontally, take two deep breaths while the glue solidifies, then neatly affix your clamps.

    Repeat as needed when you get more clamps: you can never have enough clamps!

    The red-handled spring clamps on the far right hang from a row of nails where, this being directly in front of my tool cabinet, they don’t quite knock me on the head. I really wish the original owner of this house had sprung for one more course of concrete block; another nine inches of headroom would have been just ducky.

  • Experian Triple-Alert Signup: FAIL

    So batteries.com had the usual security breach, lost the usual list of customer info, and sent out the usual letter advising the victims that they could get a free signup with Experian’s credit-report monitoring service.

    So I signed up, which involved the usual exposure of sensitive parts of my ID anatomy, and was eventually told (despite answering everything correctly, AFAICT) that they couldn’t verify that I was, in fact, me and would send a paper form to my (presumably known-to-them) USPS address for confirmation.

    The next day I get an email from “Triple Alert Redemption Customer Care <mumble-mumble@consumerinfo.com>” with this helpful offer:

    We employ a rigorous identity verification system in order to protect your personal information. Unfortunately, we could not validate your identity due to either technical difficulties with the system or information submitted that could not be confirmed.

    To continue the order process, please contact customer care at 1-866-mum-bles, Monday-Friday from 6 a.m. to 6 p.m., Saturday-Sunday 8 a.m. to 5 p.m. Pacific Time.  Please provide this Reference number (required):

    Reference number: make-up-your-own

    A representative will attempt to confirm your identity by asking you questions based on the information contained in your credit report.  Please be sure to familiarize yourself with data such as the names of your lenders and account balances before you call.  Once your identity has been confirmed, you will be provided access to your Triple Alert(SM) Credit Monitoring membership.

    Now, it’s highly likely that the email is on the up-and-up, but this seems to be precisely one of those situations they warn about:

    • you get an official-looking email
    • call the phone number
    • talk to the nice person
    • answer a bunch of probing questions
    • be assured that something pleasant will happen

    Instead, I called the “Contact Us” number from their website. The nice lady didn’t see anything wrong with them sending out an email like that. Nay, verily, she offered to do the deed right over the phone. I respectfully declined… I can wait.

    It’s worth noting that although it’s an Experian thing, the websites & email addresses involved include:

    • experian.com
    • consumerinfo.com
    • experiandirect.com

    It’s enough to make you think longingly of cutting up your cards, digging a hole, climbing down, and pulling it in after you.

    [Update: after a month or so, I got an email telling me that all was quiet on my Triple-Alert front and my delicate personal bits were in fine shape. A few days later, the long-awaited paper arrived with my confirmation numbers. So I suppose it’s working, but sheesh it doesn’t inspire much confidence.]

  • Tour Easy + BOB Yak = Useful Cargo Capacity

    Tour Easy + BOB Yak Leaf Hauling
    Tour Easy + BOB Yak Leaf Hauling

    As mentioned there, I use a BOB Yak trailer to tote stuff that doesn’t fit into the panniers on my Tour Easy recumbent bike.

    We shred dry autumn leaves, bag up the chips, store the bags under a tarp beside the garage, and then Mary mulches the weeds to death in her gardens in the spring. I usually haul a pair of bags to the garden when we ride out for groceries: never waste a trip.

    The Yak’s rear fender is a nice stiff aluminum arch with stout steel stays, built to take exactly this sort of abuse. The trailer is utterly reliable and tracks perfectly: highly recommended.

    It does turn the ‘bent into a 12-foot-long vehicle, so urban assault riding is pretty much out of the question. On the other hand, nobody begrudges me a parking space of my very own. Which is a good thing, as puny little bike racks quake at my approach.

    This looks scarier than it really is, although having the center of gravity up that high does tend to make the trailer shimmy a bit over 20 mph… which speeds I reach only going downhill.

    Update: I have a pair of Nashbar cargo nets (their deep links rot quickly, so site-search for net) to hold bulky stuff in place. One normally does the deed, but some loads demand both!

  • Tone Encoding/Squelch vs. APRS Packet Reception Reliability

    We’ve been using ham radios on our bikes for years, but last year I put together an interface that connects a TinyTrak3+ GPS encoder to the helmet mic amp. This year I’m building two more, about which I’ll write later.

    The problem is that listening to APRS data bursts isn’t all that pleasant, although it’s bearable, but it’ll get much worse when we use 144.39 MHz as our intercom frequency so we can both talk and be tracked: we’d hear all the APRS traffic within digipeater range.

    Now, admittedly, talking on 144.39 isn’t standard. The local APRS wizards have given tentative approval, as we can’t figure out a better way to talk, give position reports, and not carry two radio / battery / antenna / electronics packages on each bike. As long as we don’t do a lot of yakking, we shouldn’t interfere with the digital traffic very much… and we don’t do a lot of talking while riding.

    So I figured I’d send a 100 Hz tone under the audio and enable tone squelch, so we wouldn’t hear packets from anybody else. We’d still hear each other blatting away, but if I set the TT3+ encoders to send a position report every 10 minutes, it ought to be bearable.

    The catch with this is that some receivers / APRS decoders can’t handle subaudible tones. I considered Digital Coded Squelch, but one of our radios doesn’t include that feature, alas.

    To get some idea of how tone would work with the APRS setup around here (which is where we do most of our riding), I set up an HT on the bench with the TT3+ and my interface. The antenna is an HF/VHF discone, indoors, on the basement floor, beside a window. The GPS receiver can see a slice of sky from its perch just outside the basement window under an awning. That’s about as terrible a setup as we have on our bikes: low power, bad antenna, obscured line-of-sight.

    Each test ran 10-14 hours, the TT3+ sent a packet every 5 minutes, and I checked the raw packet results on aprs.fi.

    With tone off and the TT3+ waiting for 3 seconds of audio silence before transmitting, 39% of the packets got through to the APRS-IS backbone.

    With tone on and, thus, the TT3+ unable to hear / avoid other traffic, 47% of the packets got through on one test and 42% on another. The higher rate was overnight, when (I think) there’s less traffic on 144.39.

    Putting the gadgetry back on the bike, parking it beside the garage, and letting it run for 5 hours on a Saturday afternoon showed that 81% of the packets made it to the backbone. Some of the packets were received by stations over 30 miles away, which probably coincided with the the closer receivers hearing transmitters hidden from the more distant ones.

    The only conclusion I can come to is that tone squelch isn’t going to hurt anything around here, where the APRS wizards have done a great job of getting the decoders to cope with subaudible tones. How it’ll work elsewhere is up for grabs, but we’ll burn that bridge when we come to it.

    And it turns out that the radios take about half a second to wake up and activate the audio output with tone squelch enabled, so we don’t actually hear the data bursts: they’re almost always finished and we may hear dead air for a fraction of a second. Because the TT3+ can’t do collision avoidance, we sometimes hear other packets from other transmitters before the squelch closes again, but it’s not objectionable. Whew!

    Update: with the TT3+ set to transmit every 3 minutes, it works fine!

  • BOB Yak Trailer: Storage Thereof

    Grocery Hauling Setup
    Grocery Hauling Setup

    Bicycles, in general, aren’t set up for heavy load carrying, so I use a BOB Yak trailer for groceries, garden goodies, recycling, dead PCs, and this and that and the other thing. It works surprisingly well, tracks nicely, and tends to push cars another half-lane to the left.

    Word: if you want plenty of clearance in traffic, haul a 20-pound propane cylinder in your bike trailer!

    Anyhow, storing the trailer is a bit of a nuisance, as it’s not particularly stable on its own and takes up a remarkable amount of floor space.

    BOB Yak on garage door rail
    BOB Yak on garage door rail
    BOB Yak hanging against shelves
    BOB Yak hanging against shelves

    I finally figured out that it would hang neatly from the garage door tracks, just beyond where the door stops at the top of its travel. There’s a set of shelves against the wall, filled with the usual crap found on garage shelves (well, maybe you don’t have beekeeping supplies, but you get the idea), so the trailer isn’t blocking anything really important.

    I lean my bike against those same shelves and the trailer hangs neatly between the seat and the fairing. The ladies’ bikes are just out of sight to the right.

    We have a two-car garage that’s the right size for one minivan and three Tour Easy recumbents…

  • Byonics TinyTrak3+ GPS Power Control

    GPS power from MOSFET relay
    GPS power from MOSFET relay

    The Byonics TinyTrak3+ GPS encoder has a “Power Control” output that can switch the power to a radio or GPS interface. J6 provides the interface: pin 1 = common, pin 2 = high active.

    With the “Power Switch” option enabled in the config program, you can set the number of seconds to allow the GPS unit to get up to speed before the next scheduled transmission.

    I glued a surface-mount MOSFET relay to the back of the PCB with urethane adhesive; it fits neatly between the DIP microcontroller’s pins with one output lead soldered to the 5V pad of J7. The other lead goes to the center +V pad; because the relay uses back-to-back MOSFETs, the polarity doesn’t matter.

    That replaces the normal solder bridge across J7 that provides power (on pin 4) to the GPS2 plugged into the DB9 connector. When the relay’s on, it connects the GPS to the power supply. When it’s off, the GPS goes dark.

    The relay input is an LED with a forward drop of 1.3 V max and requires 4 mA to turn on: figure 3.7 V / 4 mA = 925 Ω max. I kludged an 890 Ω resistor by paralleling (stacking!) 1.5 k and 2.2 k resistors; you could probably use anything near that and it’d work fine.

    The relay is an OMRON G3VM-21GR1, part number A11171 from Electronics Goldmine, but I suspect any teeny little solid-state relay would work. The max on resistance is about 1 Ω and the receiver draws about 65 mA. I measured about 20 mV of drop, so the actual resistance is a lot lower than the spec.

    I initially set the power-on delay to 10 seconds, which seemed to be OK: the GPS (green) LED would blink a few times, then go solid. Alas, the warm-start spec for the Byonics GPS2 (see the GPS3 for details) receiver is really 38 seconds, average, and it was definitely producing bogus position data. So I set the delay to 60 seconds and we’ll see how that works; early reports indicate the coordinates still have plenty of jitter.

    [Update: 60 seconds is iffy. 90 seconds seems to work pretty well. A bit of rummaging says that the satellites broadcast their ephemeris data every 30 seconds, so 90 seconds allows for two complete update cycles. Maybe 100 seconds would be even better. Some old background info for Garmin hand-held receivers is there.]

    It’s obviously a tradeoff between accuracy and battery life. This is for use on a bicycle and, believe me, I don’t want to tote a huge battery!

    If the control signal was low-active, then you could use a cheap PNP transistor as a high-side power switch.

    The white/orange wire routes regulated 5 V through an otherwise unused pin to the homebrew interface that combines the GPS data with helmet mic audio. The tiny rectangle is a 1 µF cap that helps cut down digital noise. There’s no need for a connector on that end, as it’s wired directly to the interface circuit board inside a small enclosure.