Silicon Valley Redneck

Grumble grumble modern WiFi grumble

Fry's had wireless grouters on sale for $15 again - the Airlink 101  AR430W - so I picked one up, on account of my existing access point being a mere 802.11(b) slowpoke, and me having the notion that fastish access to the house network with modern security features might be appropriate.  (What I actually want is an access point, not a router, but access points weren't on sale.  I may eventually get a nice access point and stick the cheap router behind my mother's PC so's to have secured wireless access at my parents' house.)

Anyway: set it up (pretty much trivial), give it 256 bits worth of /dev/random for the key (enabling WPA-PSH/WPA2-PSK), and....

The SSID shows up.  My shiny new (well, new in 2005) dinky laptop, running Debian-stable, doesn't know how to talk to it, even after I install wpa_supplicant from source; the supplicant keeps saying authentication timed out (and logging strange errors, including "operation not supported").  If I reboot in Windows, it works.  Hmmm....

Much futzing around.  Eventually I fire up the old laptop running new Kubuntu-Heffalump, plug in the PCMCIA WiFi card, move over the same wpa_supplicant.conf... and it works.  (Well, it connects to the router; then I need to do 'ifup ath0' manually at the moment.)

Well, it could be an ipw2200 driver issue; that's an old version of the driver.  Or, mayhap, a kernel issue.  Must be time to update that system; it's still on 2.6.18.  Or maybe I have to update the whole system to -unstable, which is really not something I want to do, as the configuration is somewhat brittle (though I suppose the current -unstable might actually have better support for that oddball laptop than the version I'm running now).

Update: fixed sources.list; did a dist-upgrade to the latest -testing (which, being a several-month upgrade, needed quite a bit of manual intervention); rebooted (which worked); now it's running the 2.6.26 kernel, and wpa_supplicant tells me that I need to use the wext driver instead of iw.  OK, so I do that, and try to set up the interface/supplicant using one of the newfangled utilities, which apparently doesn't work... but now, mysteriously, when I do an ifup on the WiFi interface, the supplicant wakes up and uses my configuration file, hooray!

So, I guess if you're using a reasonably current release of Linux, WPA does in fact work, though the mechanisms may be obscure.

I also (as long as I was working on it) installed a dinky USB Bluetooth adapter, and, attempting to follow someone's slightly dated instructions that didn't really match my system, eventually did manage to pair it with my cellphone, after which a minor change to the kppp configuration let me use EVDO with the phone still in my pocket.  So, the USB-to-cellphone cable is now optional, though potentially useful for charging the phone's battery.

Well, this is annoying.

What with Firefox 2.0.x having officially reached the end of its supported life, I switched to 3.0.4 last week.

There were a couple of transition annoyances - mainly, it lost many of my newer bookmarks until I deleted all my bookmarks and did an explicit import from the old 2.0 bookmarks file, and of course I had to go out and find compatible versions of some of the extensions I use.

There's an ongoing problem, though: duplex printing.  I don't find any references to this on the Web, so there doesn't seem to be an answer (if I find one, I'll post an update).

Now, here's the thing: I have a duplex-capable printer (Brother HL-5250DN), Linux (Debian-unstable), and CUPS.  The .ppd file and lpoptions quite clearly specify DuplexNoTumble as the default... and yet Firefox insists on defaulting to DuplexTumble every freaking time I go to print something.

It doesn't seem to be one of those KDE-vs-Gnome things, either; I just fired up the Gnome CUPS manager, and it thinks NoTumble is the default.  So, unless I switch to the Page Setup tab, and change the duplex setting every time, my printouts get formatted for flipping along the short edge instead of the long edge.

Ah, well... printing from browsers has been problematic for a long time (and not just Mozilla products, and not just under Linux), but this is just plain bad integration.

A session of slow-motion head-bashery winds down

On and off for the last few weeks (IMCFT, what with work being in Busy Mode), I've been trying to add support to AGROS for the USB device interface on the LPC2148 (and thence the LPC23xx and such).

Well, it's been frustrating.  The NXP documentation isn't very good, and the various sample code isn't set up to show just how the interface actually works.

Eventually, looking at Micrium's code, I figured out what I think is the last bit of magic: Set Address needs to have the command issued to the protocol engine once (so it takes effect on the next Setup packet), not twice (to take effect immediately), and the Set Address command needs to be ACKed with a zero-length packet.

Anyway, instead of seeing a half-second (or five-second) timeout and bus reset as with the various b0rked attempts, I'm now seeing a Get Configuration Descriptor command immediately after Set Address... and I'm not responding to it, because I haven't built a configuration descriptor yet.

Off to do some real work now (you know, the kind that pays the bills).  Once I get my USB driver working properly, I expect I'll post some nice sample code that shows just how the interface gets used.

Having USB device support in AGROS may come in handy for real work soon... toss in an ACM layer and a SCPI interpreter, and it looks like part of a line of quick'n'easy custom test equipment.

(Update: the USB class for something that speaks SCPI should of course be TMC, not ACM.  I think I have a copy of the TMC spec squirreled away somewhere... and it can't be any more perverse and incomprehensible than the ACM spec... can it?)

Grrrr...

Dusting off, for the moment, my work on AGROS, I decided it was time to support the USB device interface on the LPC2148 working... 'cause that'd be a handy way of talking to gizmos.

Well, I wrote some initialization code, and a skeletal interrupt handler that just reports what the interrupt was, loaded it onto the Keil MCB2140 board, and proceeded to plug in the cable.

I got a status-change interrupt, but nothing else.

So, I looked at various other people's code, and they're all basically setting things up the same way I am, and I fiddled with stuff, and tinkered, and tossed in lots more debug kprintf()s to make sure my register definitions and settings all look right....

After much further futzery, I found someone else's precompiled USB demo application that's meant to run on the same board... converted it to hex... loaded it... and it didn't work either.

Guess there's something wrong with the board.

Maybe I should dig out the prototype beetlebot board.  That's got a USB connector on it... but I don't remember what it has in the way of a serial-port connection.  Probably needs a magic cable, perhaps connecting to one of my new USB-to-logic-level-serial boards with RESET and ISP control functions (not yet tested).

(I'm sure a USB protocol analyzer would have come in handy this afternoon, or on Friday evening for that matter, but that's not something that fits my personal budget just now.  Also, I don't know where I'd get one off the shelf on a Sunday afternoon.)

Update: Consult the LPC2148 errata sheet.  I have a very old rev chip, on which the USB interface Does Not Function if VBUS is low.  I've got the jumper installed; why isn't it working?  Oho!  Somebody at the Keil factory exchanged R38 and R39, with the result that VBUS is at 0.44V instead of 4.56V.

Guess I'll try a resistor swap this evening.  Now, it's time for breakfast, a quick hikelet, and work.

Updates 2 & 3:  The resistor swap didn't fix it.  Maybe the USB interface on the chip had gotten damaged somewhere along the line.  Time to swap in a spare 2148 I have lying around... even if it is the same antediluvian silicon revision, and just a few weeks newer than the one that came with the board.  Whoops!  Botched the removal - I was thinking I should have taken it to the office today, and used the fancy-schmancy desoldering station!  Now the board is minus a few pads, some of which were important, and #36 patch wires are such a pain... maybe I need to order a new bargain-version board from Spark Fun, and perhaps meanwhile work on the LPC23xx version of AGROS (what with having a perfectly good LPC2378 board handy).

Sometimes it is about race

Hmph.  Been mucking about with Verilog again, IMCFT, and having a frustrating time with a simple design sometimes working and sometimes not.

If it were C, or some other customary compiled programming language, I'd order the compiler to show its work... invoke -S, and look at the generated assembly code.  Alas, Verilog doesn't spit out a gate-level equivalent schematic.

I figured it had to be either noise on an input or a race condition of some sort.

Now, the trouble with being used to regular programming languages and making the transition to something like Verilog is that some things that look analogous really aren't analogous.  Fer example:

        if (!sel) begin
            // Not selected; set idle conditions
            start <= 0;
           // etc...
            probe <= 0;
        end else if (!start) begin
            // Selected; not started; time to go un-idle
            start <= 1;
            bitcount <= 8;
            // etc...
            probe <= 1;
        end // else if ...

Now, looking at that from a C programmer's perspective, it's obvious that, the outer conditions being met, if sel was false (thereby causing start to be false) and is now true, both start and probe should be set to 1.  There's no way that probe can sometimes fail to be set.

Well, the thing here is that those assignments within the if block actually happen concurrently.  So, in fact, it's entirely possible for start to get set on one clock cycle (the enclosing condition involves a clock edge), some of the other assignments not to happen on that cycle, and then, owing to start having been set, not to happen on following cycles either.

Sure enough, a race condition.

Synchronizing sel to the clock solves the problem.

Good against remotes is one thing...

Stephen Fry rants about universal remote controls.

Those things have always struck me as being a bit like Esperanto, really: universally pointless.  The concept seems good enough, but when it comes to implementing it, well....

You'd think a multi-function remote with soft controls implemented using a touchscreen ought to be useful, though expensive.  (Isn't there a Palm app for this?)  Apparently, though, they're not.  Useful, that is.  Expensive, they are.

But, then: a lot of the non-universal remotes provided with appliances are hard to use... because they try to be more than one thing.

I have (pops off to living room for a moment) five remotes, plus the cordless keyboard/trackball.  They are:

• Projector: 22 buttons, of which I routinely use ON/OFF; the three input-select buttons see occasional use, and the rest are for setup and maintenance.  This one is pretty well designed, just for the projector.
• Receiver: 51 buttons, of which I routinely use four.  Three others get occasional use.  Six of the buttons select which device it's controlling... which might be handy if I had a bunch of gadgets all made by Onkyo, which I don't (just this receiver and my old one from college, which has no remote-control capability whatsoever).  Were I to venture beyond the few buttons I actually use, this remote would become horribly confusing.
• VCR: 24 buttons, reasonably well set up for controlling a VCR... though it also has modes for controlling a TV set, a cable box, and something or other else.  As a control for those other things, I expect it would be a horrible mismatch.
• DVD player: 33 buttons, 17 of which have more or less obvious uses.  Only controls the DVD player.
• Computer: this is one of the ATI RF remotes, and I've set Xine up to understand it reasonably well.  52 buttons, not well suited to any particular real-world usage, but I've mapped about 20 of them to useful functions.

It would kinda-sorta make sense to have a single remote to handle the "usual" functions for the projector, receiver, and computer.  (Actually, if I added an IRDA transceiver to the computer, this could be a use for an old Palmoid device... I think there's a Grand Vizier still in working order around here.  If I learned to write little Palm apps, it could be a nice refinement to the home theater.  Also, it could, when talking to the computer, receive context menus over the IRDA... assuming I wrote context menu software for Linux.  Which I'm not likely to do.  So much for that idea.)

Anyway, what I was about to write, before I started counting remotes and buttons, is this: the remotes which come with appliances are often confusing in their own right.  I sometimes find myself trying to explain, to one older person or another, how to turn the TV on.

Now, you might think that turning the TV on would be simple.  But, when you look at the typical basic home TV setup these days, you have four components: the TV, the VCR, the DVD player, and the cable or satellite box.

Each of these components comes with a remote.

Each of these remotes has features for controlling the other three components.  Only those features don't work, because they're not all the same brand, nor the same vintage.

So the first order of business is to determine, and explain, which remote controls which device.  In so doing, it is not helpful that, for example, the DVD-player remote has a button which purports to turn the TV on and off.

The next thing to explain is that pressing certain buttons on any of these remotes will cause it to cease controlling the device with which it arrived, and instead attempt to control some other device which you don't have.  You may find the remote for your Zenith TV set is sending messages to someone else's Zenith DVD player, while your Panasonic DVD player ignores it.  This necessitates a recovery plan: if it stops working, push this button to make it start controlling the TV again.

Then there's the whole business of finding the input-select button on the TV remote, figuring out how it works on that model, and explaining how to use it.  It doesn't help that the VCR and cable box have their own input-select functions, which generally don't do what you want, and are labeled based on a topology that doesn't match anyone's actual installation.  (Yeah, of course you route the video from the DVD player through the VCR.  It's the obvious thing to do, when the VCR was there first.  Then you learn about Macrovision.)

So, yeah, remotes are a serious aggravation... but the universal ones are neither the solution nor the problem.

A crazy weekend follows a crazy week.

Today: living room infested with thundering herd of poodle.  (I got up early to take my parents to the SF airport, and now I'm looking after their dog for the day, pending availability of their dogsitter.)

Tomorrow: up early to drive down to the Salinas airport to watch the thundering herd of lickety-split machines.

And somewhere in there, I need to get a bit of yard work done, and do some real work on a project for a client... 'cause I'm kinda behind on that project, and in another week I'll become the bottleneck.  Besides, it's revenue work.

Must be time to do the yard work now.  Then take the poodle for walkies in the hope that a bit of exercise will quiet her down.  Then, assuming no further distractions, get the client's code at least to the point where it'll compile for the new model (leaving actual implementation of the new features for Monday).

Update: Quince season is officially over.  Quinces, you say?  Yep.  I've neglected the care of my three-in-one pear tree, and somewhere along the line it seems that two of the three ¶eargrafts died off, leaving one scraggly pear-bearing branchlet and what I guess must be rather a lot of suckers from the rootstock.  Which, app(e)arently, was quince.  So, come late summer, it's raining quinces!  Get your runcible spoon!

Field trips

A few weeks ago, I went on that one-day business trip to Inner Ruritania.  Seems a bit excessive, to spend all those hours on various planes just for one day of work at the customer site.

Well, now there's talk of sending me off to Klatch.  Way over there by the Mediterranean.  For a couple of hours.

I'm hoping I can solve the problem by some combination of e-mail and telephone.  It's gotta be something simple; the gizmo worked in the lab, and it worked in Upper Whatchacallistan, but send it off to Klatch and the computer can't talk to it.  Maybe it's the writing.  Do the serial ports run MSB-first in that part of the world?

Silly decimal points.

(Imagine that being said in a Daffy Duck voice.)

OK, it wasn't a decimal point exactly....

On Wednesday, I went to an open house at a company with which the consulting company might be doing business in the future.

They had a contest: guess the number of peanuts in a prolate-spheroid jar.

Being completely no good at such guessing, I counted peanuts around the equator, and from the approximate circumference calculated the approximate radius in peanuts, and thence the volume of a sphere in peanuts.  Applying a fudge factor to account for elongation, I came up with a number a good bit higher than I would have guessed.

Well, the results (including the peanut count) came out this morning.  I was high by just about a factor of two.

Think maybe I had a math error in there somewhere?  A brilliant plan foiled by a silly miscalculation?

I may be a bit Daffy this morning, but I have the feeling I was Wile E. on Wednesday.

Well, that went smoothly. Mostly.

Up two hours earlier than usual, deal with essential morning stuff, leave the house about the time I normally start to think about waking up, drive to San Francisco Airport in plenty of time for my flight to Ruritania International (actual destination omitted to protect the client's identity), arrive on time, meet up with the boss's brother, proceed to a small town in Inner Ruritania, find the small unmarked building we're looking for, get the tour, have a productive discussion with the owners, return to Ruritania International about 40 minutes before flight time, check in, have a few minutes for reading before boarding commences, get on plane, arrive at Regional Hub on schedule, find the gate for the connecting flight, grab a slice of overpriced airport pizza, dig out the laptop and hook it up to the cellphone (Ruritania International had banners advertising free Wi-Fi, but I didn't have time to check it out; Regional Hub has Boingo, which redirects to what I assume is meant to be a show-me-your-credit-card page, but it was broken, at least with Konqueror), make a quick scan of e-mail and news, return to reading the book I'd brought, board the third plane of the day, return to SFO about 15 minutes early, get home about 1-2 hours past normal bedtime.

Whew!

Three planes in a row running on time, with no sitting around burning fuel while waiting for a turn to take off, and no problems with security.  (Flight #1 was Skywest as United; #2, Skywest as Delta; #3, Delta.)

The seats are still made for people without shoulders, though.  Luckily, on flights #2 and 3, the seat next to me was vacant.

Oh, and the windows on the CRJ200 are evidently meant for children, or at least for someone a lot shorter than I am (and I'm not exactly uncommonly tall).

I was a little confused to find that the flight from RI to RH had two numbers, with the same digits but not in the same order; the sign was showing both, but the number they announced wasn't the one on my boarding pass... but, it was at the right time, from the right gate, to the right destination, with the right airline, they let me get on, and there wasn't somebody else in my seat, so I guess it must have been the right plane.

The real confusion: SFO.  The signage there sucks like a bilge pump.  I wanted to park in short-term parking for Domestic Terminal 3, which I think should have been Garage F... but following the signs for "Short-term parking" got me dumped in Garage A, with an option for Garage G.  OK, so I park in A, and head for the terminal.  Now I'm in International Terminal A, and there don't seem to be any signs directing me to the domestic terminals.  So, I wander around, and eventually find the "AirTrain" thingie (not to be confused with AirTran, for which there were also signs), which goes around in circles and eventually delivers me to Terminal 3.  Getting off the plane, I'm confused again, and it take me quite a while to find the AirTrain.  Then, exiting the garage, I attempt to follow the signs for the freeways, discover that signs are sparse and often lacking arrows at complex intersections, and find myself driving a long way past a cargo terminal with no reassurance that the road eventually leads to the freeway, which I can see just over there on the left, if only my car had a teleport button.  Yes, the road did connect to the freeway, but having some clear signs along the way would have been nice.

Well, I don't in fact seem to be sleeping in this morning... got a bunch of stuff to write up for work.  It was a highly educational meeting.  Apart from the work stuff, I established pretty well that I don't have any latent vegetarian tendencies... and, surprise surprise, that NIMBYs can be a wildly dishonest bunch.  (Elaboration may follow, with identifying details suitably scrubbed to protect the client from militant NIMBYs and other radical elements.)