Author: Ed

KMyMoney Exports: Don’t Use Double-Quote Marks

So when I entered that impact socket in KMyMoney 0.9, which is how I do my exceedingly simple bookkeeping, I entered it just like that: 1-1/16″.

That worked fine, right up to the point where I exported the summary of transactions report in CSV (comma-separated-values) format and tried to open it as an OpenOffice spreadsheet: only the first third of the file made it into the spreadsheet.

Having screwed up exactly like this before, I knew where to look: CSV format wraps fields with double-quote marks and KMyMoney isn’t bright enough to escape the double-quote mark, resulting in a broken file. That may be fixed in the current version (1.0.2 right now), but I’m still running Xubuntu 8.10 with some KDE-based programs spliced in because KDE 4.x still has problems with rotated dual monitors.

That escape mechanism is actually part of the CSV standard, such as it is:

Fields with embedded double-quote characters must be enclosed within double-quote characters, and each of the embedded double-quote characters must be represented by a pair of double-quote characters.

I knew better than that, but it’s an easy mistake to make.

What really ticked me off, though, is that KMyMoney breaks the transaction into two parts (it’s a double-entry bookkeeping system, after all) and, even after I changed the double-quote to the word inch, refused to update the other half of the transaction. Furthermore, I couldn’t get access to that half; the only description I could find had inch.

Had to delete the whole entry and add it back to get it right… which was better, long term, than hand-editing the CSV file every time.

2010-01-18
Money for Nothing: Nielsen TV Survey

Just got a check for twenty bucks in the mail:

Nielsen Survey Thanks

That’s in addition to the ten dollars folding cash money enclosed with the survey as, I suppose, a motivation to not chuck the whole thing in the trash.

The survey told us that our household had been “scientifically selected” to ensure a valid sampling of the TV viewing population, so it was very important to return the survey. I was astonished that they’d pay thirty bucks for a survey, but that’s probably a good indication of their desperation.

OK, sez I, I’ll play along; every man has his price.

It took ’em until Question 4 to get to the heart of the matter: how many television sets does our family own? Surprisingly, the first choice was “None” and, because that best describes our situation, that’s what I picked. Most of the other questions didn’t have a “Hell, no!” response, but I picked the smallest numbers, hours, and viewers they allowed.

While there is, in fact, a TV in our house, it’s parked on a basement shelf with its cord wrapped around it and hasn’t been turned on in years. Sort of like the “iron phone” I keep in a box nearby; it comes out when I must verify that the phone company’s problem is upstream of the jack on the side of the house.

And, besides, it’s an analog TV and we all know what that means: ain’t none of those signals on the air these days. Yes, we have a cable connection, but the only thing crossing the jack is Internet data and, IIRC, the Cablevision diagnostic channel.

We have a lot of time for interesting & productive projects. They didn’t ask about that sort of thing, though.

Our results were, most likely, something of a disappointment.

[Update: OK, three times is enemy action. I will delete further comments asking to be signed up for the survey. ‘Nuff said.]

2010-01-17

Thinkpad 560Z Configuration

Turns out the ancient $20 Thinkpad 560Z I’d been using to capture WWVB receiver data didn’t have the IBM configuration utility on it, which made it tough to tweak the LCD timeout. The key parameter for this laptop is that it runs at about 8 W with the LCD turned off, which is just what you want for long-term data collection.

The thing runs from a 2 GB CompactFlash card stuck in a CF-to-IDE adapter, so it has a (rather slow) solid-state hard drive. The nice part is being able to just jam the CF into the card reader on my desktop box, make appropriate changes, and pop it back in the 560Z.

Xubuntu automagically mounts all the partitions, so that part is easy. It has a FreeDOS partition that runs the DOS-only config program, a swap partition (not heavily used), and an Ubuntu 8.04 command-line-only installation.

The IBM config stuff is in a directory on a hard-drive image (saved from the picture frame project), so mount that and copy it over:

sudo mount -o loop,uid=ed,ro,offset=$((63*512)) develop.hd /mnt/loop
cp -a /mnt/loop/ThinkPad/ /media/FreeDOS/

While figuring out what to change, it occurred to me that I should just make a batch file with all the proper settings. Here’s a cheat sheet for the available settings:

Refer to ps2.msg for raw help file
 some commands/options do not apply to 560Z

1. Power Management
DEFAULT     suspend time, screen off, HD off, standby time, proc speed
DISK        power-down timeout
SAfe        safe suspend
S2H         suspend to hibernate time
PMode       power mode
ON          auto-on date/time from suspend
RI          resume on Ring Detect from serial port
HSWITCH     hibernate on power off
SErial      serial port enable
HFile       create hibernation file
HTimer      time to hibernate
CPUPower    stop clock when idle
POwer       time to suspend
Cover       suspend with closed cover
TImer       Power command = suspend or hibernate
PCIBUSPower PCI power saving
LCd         time to display power off
DOCK        suspend when docked
LBattery    suspend / hibernate with low battery
SPeed       CPU speed selection

2. Display Device
SCreen      select LCD / CRT
HVEXPansion expand 640x480 to 800x600
F8          F8 selects LCD expansion

3. Alarm Related
BEEP        beep settings

4. Thinkpad Setup
IRQ         interrupt assignments
JStick      joystick config
PCIIRQ      PCI IRQ assignment
DMA         DMA channel assignment
PARallel    parallel port config
IR          IR port config
KRate       keyboard repeat rate
SERA        serial port config
AUdio       sound system config
FNSticky    sticky Fn key
STARTup     display startup screen
MIDIport    MIDI config
TPOint      Trackpoint enable / disable
PRESENtation  disable screen, standby, suspend
AUDIOCTRL   audio control port config

5. Others
SUSpend     suspend NOW
FDD         diskette drive int / ext
OFF         turn off NOW
HIBernation hibernate NOW
TURN        turn off NOW
BRightness  LCD brightness on battery

And then the batch file:

ps2 default
ps2 disk 0 ac
ps2 pmode custom ac
ps2 serial off
ps2 hfile c
ps2 htimer 0 ac
ps2 power 0 ac
ps2 cover disable
ps2 lcd 5 ac
ps2 speed auto medium ac
ps2 hvexpansion off
ps2 jstick disable
ps2 parallel disable
ps2 ir disable
ps2 krate fast
ps2 sera disable
ps2 audio disable
ps2 midi disable
ps2 audioctrl disable

The time-of-day clock drifts with breathtaking speed, which may have something to do with the CPUPower option that shuts the processor clock off when there’s nothing useful going on.

2010-01-16

Character-string Histogram

I’m in the midst of counting glitches on a WWVB receiver, a glitch being any pulse with a duration that isn’t close to 200, 500, or 800 ms. It’s useful to know the pulse width distribution, which is what a histogram does for a living.

Rather than a graphic histogram, though, I’ve been using a character array (a string!) with one character for each possible pulse duration, measured in units of 20 ms. The value of each character indicates the number of pulses having that duration during the previous minute.

The counting sequence goes like this:

No counts: . (a period)
1 to 9 counts: 1 .. 9
10 to 35 counts: A .. Z
36 to 61 counts: a .. z
More than 61 counts: !

So a minute with no glitches (and a valid WWVB time code frame) looks like this:

.........4S9............462............322.........

The three clusters show the three valid pulse widths. The pulse widths from the receiver have an inherent jitter, plus the usual ±1 jitter you get for free when you digitize something, plus (this being RF from half a continent away) whatever the Lords of Cosmic Jest do to the signal. So each width usually occupies two or three cells.

The 200 ms binary zero pulses form the cluster on the left: that “S” is equivalent to 10 + 18 = 28 counts. Add in the 4 and 9 on either side and you get 41 binary zero pulses.
The middle cluster has the 500 ms binary 1 pulses: 4 + 6 + 2 = 12.
Each WWVB time code frame has exactly seven 800 ms frame markers, which form the cluster on the right end: 3+2+2 = 7.

Add them up: 41 + 12 + 7 = 60. That’s exactly the right number of pulses in a minute. What a pleasant surprise!

A minute with three out-of-spec glitches looks like this:

1...1....6NC2............82.......1.....51.........

And a minute with very high noise that pretty much obliterates the WWVB signal:

f!!jHC6AB746312.2121..2.1..........................

Here’s how all that works…

The histogram counters form a character array that’s also a string. There are 50 20-ms Jiffies in each second (given by the obvious constant), so the histogram has 52 entries: 50 valid counts (0-49), 1 for “more than that”, and 1 for the null byte at the end of the string.

char    Durations[JIFFIES_PER_SECOND + 2];

Initialize each counter (character) with the starting value and jam a binary zero at the end:

memset(Durations,'.',sizeof(Durations)-1);
Durations[sizeof(Durations) - 1] = 0;

And then tick the appropriate counter as each pulse arrives:

Index = min(PWM_Width,sizeof(Durations)-2);

switch (Durations[Index]) {
 case '.' :
 Durations[Index] = '1';
 break;
 case '9' :
 Durations[Index] = 'A';
 break;
 case 'Z' :
 Durations[Index] = 'a';
 break;
 case 'z' :
 Durations[Index] = '!';
 break;
 case '!' :
 break;
 default :
 Durations[Index]++;
}

The switch statement maneuvers the counting sequence through the digits, uppercase and lowercase alphabet, then enforces a stall at the maximum count value of “!”. You can’t just increment each element without some checking, because you do not want unprintable control characters in the string.

Then you print the histogram as you would any ordinary string. If you’re using an Arduino, as I am, this will suffice:

Serial.println(Durations);

All this depends on the ASCII character set’s numerical sequence. Ponder the charts there and all should become clear.

Here are the histograms from an hour of WWVB reception during the late afternoon of New Year’s Day: watch the noise floor rise up and eat the WWVB signal…


.........7OD............36............133..........
 .........BID1...........37.............6.1.........
 .1.......9O91..........262.............43..........
 ........27V2............272............421.........
 .........4Y41...........46............124.........2
 .........AP71...........2811..........123.........2
 .........AN9............731...........1.6..........
 12.111..28IB11.........1623.......2..1.42.....2....
 1412...125Q911..........461.....1......41..........
 1........8Q81..........137...1.........15..........
 .12....119N912.........116..........1.132..........
 1521..1.17O931...1......27...........1..5..........
 .12....12BKB2...........332....1......132.......2..
 25211.1.3AHB5......1...1143........1...14.........3
 45412...4BDA4..12.......25111..1.....1..22.........
 6A44322.26CI53.2.1...1..343...1.......1.11.........
 5D75531113FG511...12..212313.1........1.2..1.......
 1432.1.119GB41..........262.1...11.....14..........
 .5211..115MB4...........441............14.2........
 .4.1....25JB6...........442.........1..231.........
 6B443...27I772..........2322.....1.....1221......2.
 4555411.27HA321........3232......1....114..........
 3232.1.129GI1...1.......4321...1.1.1...111.........
 ...1..1.19O8..1....11...262............24..........
 11......2AN62...........622...........124..........
 111.....2BJ551..1......1522........3..141........21
 1421....29N611.......1.136............1231........2
 1.12.....AIB3........1..38...1........312..........
 7F42..1.28FE341.1.1.....351........1...12...1.....2
 .23......8GG2....11....2423............33..........
 112..13.1AK931.....2....142....2.11.1..3.1........2
 423111..44JD4.2..1.....1433........11111...........
 1413..1.3CL812..11......242..1....11...21.........2
 474112.34AI84.2...3.1...16.2.....1...1.11..........
 8LHC734657D857411..11...131......1..1.1...........2
 JuSFDCCDDCD662412...1..............................
 VmG376788AC8671.21.1..3.......1....................
 IlCB4576CFE532131.11.1..1.1........................
 KxN798EB98A7422...2.1...1..........................
 AYL96853CF7742121311.13..21....1...................
 8TDEB6649A7952..32.41..124.....1.....1............2
 DeO78638C9GA6142.15111..........1........2.....2...
 AcPC83426BD4823.122..11132.1.......................
 7SF31121AHFB73..2.111...321..1.1...................
 7F3221414GG5411.111121.133...1.1.1.................
 6RD9669647F7361.31.2..1212...1.....................
 6L71.2444ALB21...221.212321..2...1...1.............
 4LHFD7638C9B12.31341.22113...2..........1..........
 264321112EFA5.112.22.2.14111..1.....1...1.........2
 235511445BEC3.12..1131.131..1.1........11..........
 7UC741635AAC442.1..112.1..11311.......1.1.........2
 EVLCAB3598E752252133.111.1.1..........1...........2
 JnTE9913A59A452331.13..1222.............1..........
 f!!jHC6AB746312.2121..2.1..........................
 !!!iMB772.4532..1.1.1.1..1.........................

2010-01-15

Sears Craftsman Radial Saw Elevation Knob Handle

Broken Knob

Mary’s folks visited us for Christmas and her father brought along a shelf that needed cutting; their apartment doesn’t have room for his shop equipment, alas. I cleared the crap off the radial saw, grabbed the elevation knob to crank the blade up to get it set for ripping, and … the handle broke off.

That’s not the first time this has happened, so I wasn’t entirely surprised. The knob is large enough that I could complete the mission just by grabbing the rim, but it was a near thing.

The handle is made of some wonderful engineering plastic that doesn’t solvent-bond well with anything in my armory, although Plastruct had enough bite to make me think it would work. That repair actually lasted several years of admittedly low-duty-cycle use, but obviously this couldn’t continue.

Stress raiser

The problem seems to be built into the handle design. This pic shows that the fracture spans a high-stress part of the handle: between the inside right-angle corner (upper left) that rests on the outside of the knob, across the handle’s web, to the corner of the recess in the flange at the bottom of the picture.

The red hoodickie is the latch that secures the handle in its deployed position, wherein it sticks out at exactly crotch height for average human males. That accounts for the fluorescent red tape around the handle.

Broken surface

You can see how the latch recess triggered the crack: that notch where the latch wraps around must be the highest-stress part of the handle. I suspect the original design didn’t have the latch (or had something different) and the fat web near the round feature on the left extended all the way to the angled flange on the right.

That would work!

I epoxied a pair of rectangular brass tubes across the fracture inside the web, where they fit neatly below the latch. I roughed up the web with an awl to give the epoxy more surface to grab.

Incidentally, this is one of those cases where you might think a cyanoacrylate adhesive would work. It won’t: too much shock, too much pressure. I used it to hold the parts together while the epoxy cured, but that’s about as far as I’d trust it.

I’d like to add something to the notch, but I’m not convinced a right-angle brass flange and some epoxy will have enough grip to make any difference. It would certainly require changing the latch, perhaps by thinning the left side, which would make that weaker. On the other paw, I can probably eke out a miserable existence without the latch.

Brass internal reinforcement

The picture shows the clamping in operation. A snippet of polypropylene (from some random consumer packaging) under the tip of the clamp prevents it from becoming one with the project; the clamp tip is slippery plastic, but you never know.

Perhaps this fix will last for a few more years…

Y’know, I’m beginning to believe that finite-element analysis will be the death of us all. Obviously this handle was modeled to a fare-thee-well, with only enough material to meet the expected stresses in the expected directions. Unfortunately, the real world doesn’t cooperate: the forces are always larger, the conditions always worse, and the materials always weaker than the design anticipated. A “safety factor” of three or four or maybe even ten just isn’t enough!

2010-01-14
Arduino Serial Optical Isolator

Optical Isolator – oops

It turns out that attaching some, but not all, of the PCs around here to the Arduino Pro board controlling the Totally Featureless Clock cause the WWVB receiver to drown in a sea of noise. In fact, just touching the USB cable’s shield to the FTDI Basic USB-to-serial adapter would bring the noise.

So this is a quick-and-dirty circuit to see if optical isolation will reduce the problem enough to be bearable.

The schematic is pretty simple: two bits in, two bits out.

Optical Isolate Schematic

The layout puts the DIP isolators on the top and the SMD resistors on the bottom. I used fancy screw-machine IC socket pins, just because I had some, but you could solder the isolators directly to the board. The FTDI Basic connects through header pins and the Arduino connects through female header sockets, both soldered sideways to the top of the board. I’ll eventually reinforce them with some epoxy, never fear.

Double-size PCB layout:

PCB Layout

Actual-size copper images. Remember that the top copper is flipped left-to-right here so it comes out properly after toner-transfer imaging.

Copper

And the placement info showing where the parts wind up. This is sort of the silkscreen for the top and bottom, both together: the backwards stuff goes on the bottom side.

Top and Bottom Silkscreen

The alert reader will note that the photo doesn’t match the rest of the images. Nay, verily, eagle-eyed readers will have picked out a few resistors on the top and two embarrassing little red-wire Xes at the connectors. Somehow, I managed to swap the RxD and TxD pins, even with an FTDI board on the desk next to me. I hate it when that happens… so I fixed the schematic & layout for the next time around.

The resistors push a lot of current through the LEDs and phototransistors, which is what you need to get decent 19200 b/s serial data pulses. Here’s what the data stream out of the TxD isolator looks like:

Optoisolator – TXD

I have the Eagle files and the CNC drill file for my Sherline mill if you must have them, but you can go from those images above directly to the hardware. It’s an evening’s work, more or less.

You might want to kludge a jumper into the Reset line so it’s impossible to accidentally reset the Arduino. Sometimes you don’t want a reset, like after a few days of data collection…

Now, does it actually do what I expected? The early reports are good, but I’m at the mercy of the atmosphere and must collect a few days (actually, nights) worth of data to find just how far down the noise went.

2010-01-13
Corelle Sliver

Mary found a sliver chipped from the outside edge of a Corelle dinner plate, which provides an opportunity to see something that’s normally invisible: the ceramic layer inside its glass coating.

Overall, the sliver is nearly two inches long and about the same width as the plate is thick.

Corelle sliver

Peering through the microscope at the left end, the glass layer is most obvious along the top edge. You can barely see it along the bottom, where the chip thins to a razor edge.

Corelle sliver – detail

On the right end the upper and lower glass layers are a bit more obvious, at least with the light arriving nearly horizontally and after some aggressive exposure hackage,

Corelle sliver – side light

The ceramic has a slightly higher coefficient of thermal expansion than the glass, so it puts the glass under a tremendous amount of compressive stress as the newly manufactured plate cools. Glass is really strong in compression (and terribly weak in tension), so the plate becomes remarkably hard to break. More details there and there.

The plate rims do tend to chip, however, if you own them as long as we have. These are the long-discontinued Old Town Blue pattern: over three decades old by now.

Oddly, they’re still under warranty: back in the day, Corning sold its then-new Corelle with a Lifetime Warranty. Nowadays, you get three years for the mid-grade line, five years for thicker plates, and a mere one year for stoneware (whatever that is). I suppose enough people actually took them up on the warranty to make it economically impractical.

I ran a fine diamond file over the chipped edge and it’s OK. Eventually, we’ll break down and get new plates, but there’s no sense rushing a decision like that…

2010-01-12