Posts Tagged Memo to Self
Even though I know heatshrink tubing contracts by (or to) 50% of its expanded size, this was still startling:
That’s a test for another repair on the never sufficiently to be damned Samsung vacuum cleaner, about which, more later.
Memo to Self: Pre-shrink the tubing about 3/4 of the way.
The Dell Optiplex 760 that I’m using as a rendering box has an internal “business audio” speaker that is not disabled by plugging an external speaker / earphone into either the front or rear audio output jack. The tiny volume control applet in the Xubuntu 12.04 notifications panel doesn’t provide any control over the sound card; it’s definitely not a mixer and its Sound Settings button calls up the Pulseaudio configuration which is oddly unhelpful.
xfce4-mixer, add it to the panel, fire it up, select the
HDA Intel “sound card”, enable all the controls, slide rightward until
Mono appears, click the speaker button under the slider to mute it, and you’re done.
Memo to Self: there ought to be a BIOS setting for that.
For reasons best left to the imagination, we needed some large signs for the front yard. I must look this up every time I do it, so here’s the process…
- Create document in LibreOffice (or whatever), save as PDF
- Convert PDF to EPS = Encapsulated Postscript
posterto enlarge & paginate
- Convert PS to PDF for ease of printing
Bash does the heavy lifting, after you install whatever packages your Linux distro may not have included:
pdftops -eps OnePage.pdf PosterPage.ps poster -v -m Letter -p20x28i -o PosterMulti.ps PosterPage.ps ps2pdf PosterMulti.ps
Then it’s a simple matter of a cutting mat, a razor knife, a glue stick, and some tape…
Memo to Self: Align the lower row along the hardwood floor planks!
Our Larval Engineer reports that the current techie-thing-to-do involves having a tattoo artist or other unlicensed medical technician implant a tiny bar magnet in one’s finger, a process that adds a sixth sense to one’s built-in repertoire after the anesthetic shot of whiskey wears off. Evidently, converting magnetic field variations into mechanical force tweaks those little nerve endings wonderfully well, provided that your finger doesn’t subsequently rot off.
I point out that a magnet epoxied to a fingernail would probably get you within a few dB of the same result, minus the back-alley surgery thing. She counters that’s tacky and lacks style.
I point out that her medical insurance (for which, harumph, we are currently paying) probably doesn’t cover self-inflicted damage. She counters that most
victims people have no problems at all.
I point out that a steampunk-style wristband incorporating a Hall effect sensor, LEDs, and maybe a vibrating pager motor would be at least as cool and probably marketable, to boot. She returns broadside fire by observing such a device requires power and she knows how I feel about batteries.
Game, set, and match.
In the interest of science and so as to not be rendered completely obsolete, I’ve epoxied a small neodymium magnet to my left little finger to discover what the world feels like. It’s surrounded by epoxy, which ought to prevent corrosion & deterioration until it eventually falls off or the nail grows out. It came with a white ceramic layer on one pole, which means it’s completely encapsulated:
She’s absolutely right: it’s tacky and lacks style.
I used JB KwikWeld fast-setting epoxy. The magnet attracted a tendril of uncured epoxy, so the “steel filled” part of the description seems accurate, and the magnetic field produced a nice smooth coat over the entire side of the disk.
It buzzes gently inside a Sonicare toothbrush handle, snaps firmly to steel surfaces. and is otherwise inoffensive. I must run some calibration tests to figure out what sort of magnetic field intensity a fingernail can detect. I’m certain it’s less sensitive than an implanted magnet, but I’m down with that.
Memo to Self: If you should occasionally use your little finger to ream out your ear or nose, that’s just not going to work any more…
Two lots of linear Hall Effect sensors arrived from halfway around the planet, labeled AH49E and OH49E, and roughly corresponding to the original Honeywell SS49E. The Honeywell datasheet has a non-obvious pinout diagram (that one is better), so I poked one of them into a breadboard and tried it out.
Fortunately, I got it on the first try. Facing the tapered side, with the leads downward, pin 1 is on your left:
- Power – typically +5 V
- Output – 0 gauss = 2.5 V
The chip [may | may not], depending on which datasheet you use and which part you have, include an internal 65 μA load on the current source, so you [may not | may] need an external load resistor.
Without a load resistor, this one worked fine. Old-school ferrite and ceramic magnets push it about 1 V off-center, neodymium magnets saturate the output.
That Honeywell / Micro Switch handbook should dispel many misconceptions about proper use, calibration, polarity, and suchlike.
Memo to Self: verify the output voltage for both units with typical load resistors.
I’ve completely offloaded remembering my appointments to the Kindle Fire, which now lives in the right thigh pocket of my cargo pants (it’s a sartorial thing). While waiting for a meeting (which it had correctly reminded me of) to start, I did my usual “What do we find in the way of open WiFi networks?” scan, found one, and connected to it. Unfortunately, it was one of those open WiFi networks that subsequently requires a password, but … then I noticed something odd with the time displayed at the top of the screen.
A bit of tapping produced the Date & Time settings screen:
Evidently, that not-exactly-open WiFi network also features a defunct time server that’s happy to clobber any device asking for a time update. As you might expect, snapping back forty years does horrible things to many Kindle fire apps. The crash handler can only suggest re-downloading the app from the online store, which turns out to not be necessary after a complete shutdown / reboot.
Ah, if I knew then what I know now… I’d certainly get into much more trouble. Not surprisingly, there’s a book about that; maybe it’s better not to know how things will work out.
Memo to Self: watch the time!
Back in December 2007 I printed four copies of a picture on various papers with the Canon S630 and hung them up a floor joist over my workbench, directly below a fluorescent shop light. Having just hung those screwdrivers where the pictures used to be, it’s time to see what’s happened.
The pictures, scanned on an HP C7670A (aka Scanjet 6300C) against the neutral gray of the ADF platen:
The papers, clockwise from lower left:
While the scanner isn’t renown for its color fidelity, the overall results look about right; the platen really is that shade of gray and the upper-right picture has a sickly green hue.
The faded edges along the right side of the left-hand image show where the adjacent sheet overlapped: the colors didn’t fade nearly as much. The small rectangles on the lower left corners of the right-hand images show where I put clothes pins to keep the sheets from curling.
All of the images have a blue overtone; the magenta dye fades out with exposure to UV from the fluorescent fixture.
As you’d expect, the glossy paper looks best, with very crisp detail. The inkjet paper is next, followed by the matte, and the plain paper in the upper right obviously doesn’t support the ink well at all.
Of course, after five years I no longer have any of those papers and am using entirely different ink…
To show that the scanner really does matter, here’s the same set of images from a Canon LiDE 30:
In both cases. that’s without any color correction / gamma compensation / whatever. I should fish out my scanner calibration targets and go through the whole color calibration dance again; with any luck, the Linux color management infrastructure will be less inadequate by now.
Memo to Self: If you love it, don’t expose it to UV.