N1VG Weblog

Defeating the SentriLock Realtor Lockbox

2011-05-08T19:24:00.000-07:00

It's been a long time since I've done any physical security hacking, but recently I came across an interesting vulnerability almost by chance.

For some time I've had an old SentriLock Realtor lockbox kicking around in the garage. It's the type of thing your real estate agent puts on the door while your house is on the market so other agents can get the key to show your house. I didn't have any way to get it open, so I'd never made any attempt to figure out how it worked. Last year I did a liquid nitrogen demo for a bunch of friends - we spent an evening breaking things and making ice cream. While I was gathering up things to freeze and break, I came across the lockbox. I threw it in the pile, and when we were done shattering carnations and racquetballs, we soaked the lockbox for a couple of minutes and attacked it with a sledge hammer. The box held up reasonably well, but a solid blow to the key compartment door shattered it.

The unit sat on a table for about a year, and recently I saw it there and realized that with the compartment open, the only thing holding it closed was a pair of screws. I took them out with my Leatherman and opened it up.

(Pictures to follow later, I left the unit in the shop and I'm blogging from home on a dull Sunday night.)

There's a single circuit board in the unit with the contacts for a rubber keypad on one side and components on the other. The only actuator is a small gear motor that drives the latch mechanism. This is where I noticed a design flaw.

The motor's leads connect to the PCB near the '1' button on the keypad, and the pads are exposed on the keypad side. The keypad itself is soft silicone rubber, and the PCB is separated from the front of the housing by the thickness of the silicone sheet. Therein lies the problem: If you rip off the '1' button (or the do-not-disturb indicator) you can stick a couple of angled probes (I used curved tweezers) into the hole and inject a voltage directly to the latch motor. With properly constructed probes, you could probably do this by piercing the keypad and not have to damage it significantly. As it is, you could easily stick the button back on with some silicone adhesive around the edges and very likely avoid detection.

My unit was pretty significantly damaged by the beating it took from the sledge hammer, so I can't do a proper demo here. If anyone happens to have an undamaged unit they'd like to contribute, I'd be happy to give it a shot.

I emailed the company to inform them of my discovery, and to my surprise I received a response from the founder and CEO, Scott Fisher, within an hour. He stated that the model I've got hasn't been made in a few years, and that there have been improvements since then. Based on the white paper for their new model, it sounds like they're meeting significantly more stringent security standards these days.

The chances of anyone using this flaw to break into a house are pretty slim, especially when a rock through a window will accomplish the same thing. What's most interesting to me is the gap in their analysis of the threat space that this vulnerability would imply. The mechanical construction of the lockbox seems to be more than adequate - I'd certainly have had a lot of trouble forcing it by less violent means than I used, especially if it was still hanging on a door. And presumably the smart card system has a reasonable degree of security (though this is something I'd also like to check out if I had time), but it's like they didn't anticipate a direct electrical attack on the PCB. Simply relocating the motor leads would have made it considerably more difficult to exploit - there could still be other interesting traces accessible through the keypad openings, but they'd take considerably more precision to tap into.

It also seems likely that it was an economic decision that led to the flaw. Using a single PCB to handle both the control functions and the keypad undoubtedly reduced component costs, mechanical complexity, and assembly time, but compromised the design in a way that would not be tolerated in something like an electronic safe or an alarm system.

In fact, next time I'll cover the cheap Chinese safe I just got on eBay - and how they got the keypad separation right, but still managed to leave the safe vulnerable to a simple, non-invasive attack that lets an unskilled intruder open it in seconds without any tools. It's simultaneously an interesting flaw and kind of a bummer, since I'd intended to actually keep stuff in the safe.

Update (5/9/2011): Scott Fisher at SentriLock says my approach won't work with an undamaged unit, but declined to elaborate. If anyone has one that hasn't been beaten on with a sledge hammer and frozen to -320 F, let me know and we can see if he's right.

Black Rock City Navigator

2011-02-14T14:42:00.000-08:00

Black Rock City 2010 Satellite Image

For those not familiar with Burning Man, the week-long festival is held on a dry lake bed in Nevada's Black Rock Desert. The ephemeral Black Rock City, temporary home to more than 50,000 people, is shaped like a giant 'C' and features a network of streets arranged in a polar grid. While navigation is usually simple -- provided the navigator is sufficiently sober to read and comprehend street signs -- blowing dust can create frequent white-out conditions with near-zero visibility, and all of the street signs are traditionally swiped as souvenirs toward the end of the event.

While the fine folks at Burning Man Earth do an excellent job mapping the city each year and can provide maps for hand-held GPS receivers and smart phones, I decided that I wanted to build something more unique and specialized for navigating at my first Burn.

In the customary manner of many Burning Man projects, this started out as a grand concept involving a lot of blinking lights and machined brass, and ended as something considerably less grand and more rushed, but surprisingly functional nonetheless.

My initial idea for a ‘golden compass’ style device turned out to be a bit beyond my machining skills – or at least my time-management skills. Instead, I chose a 4” black sewer pipe end cap as the housing for the navigator. I did apply some green metallic star stickers, though, which I think really added something.

The size meant it wouldn’t be suitable for carrying in a pocket or on my wrist, but it would fit on my bicycle handlebars just fine. I even found a ball and socket swivel with a quick-release that worked beautifully for this purpose. I’m still not certain why I had a box of swivel mounts in my shop – most likely Electronic Goldmine had a sale on them a few years ago – but sometimes my pack rat nature pays off.

The next challenge was the display. I considered a cross-needle meter, but they're hard to find, and would be hard to see in the dark. I also thought about a persistence-of-vision display with a rotating LED array, but not having dealt with slip rings before, I wasn't sure I could get rotating contacts to work right on the first try. I looked at a few other options and decided on a linear array of LEDs rotated by an R/C servo, underneath an engraved acrylic map of the city. The servo would move the array into the proper position and a single LED would light to indicate the user's location.

I'd never used servos before and I'm not great with mechanical design, so I was a little worried about that part. I had a few servos kicking around in the shop, so I plugged one in and started experimenting. They turned out to be easier than I expected to work with, but I quickly discovered a flaw in my plan: the servos only had about 170 degrees of travel, and I needed to cover at least 240 degrees on the semicircular city map.

I decided against trying to modify a servo (or rather, I broke one in the attempt and decided it wasn't worth the trouble) and didn't want to use an expensive sail winch type, so instead I made the pointer board with two LED arrays at a 90-degree angle. By selecting one array or the other, I could move the pointer LED across 280 degrees.

Electrically, I kept the design about as simple as I could. The main board has a Freescale MC9S08AW32 microcontroller, voltage regulator, and hookups for the pointer board, GPS receiver, and servo. The pointer board has another MC9S08AW32 and two arrays of 32 super-bright green LEDs. The MCU on the pointer board simply turns on and off LEDs in response to serial commands from the main MCU. I'd considered a few designs with specialized demultiplexer/driver parts, but realized there wasn't much point when I had a tray full of suitable MCUs on hand (costing somewhere under $4 each), and the slave software would only take a few minutes to write.

Disassembled

The software for the main board mostly reused bits and pieces that I'd written for other projects. The NMEA 0183 parser for the GPS receiver data and the routines to calculate distance and bearing were the most important of these. These were swiped straight from my Tracker2 source code, which is GPL'd and available at www.argentdata.com/community. I tweaked the distance calculation (a rough approximation since the Tracker2 doesn't need exact distances) for minimum error at the latitude of Black Rock City, but left the rest unmodified. Everything else was fairly simple logic to glue it all together, move the servo, and select an LED to turn on.

The best map I could find of the city was in PDF format, so I imported it into Photoshop, cleaned it up a bit, and exported it to the Dr Engrave program that came with my MDX-20 milling machine. Of the fluorescent acrylic sheets I had on hand, orange and green seemed to work best. I chose green to match the LEDs and my bicycle. Getting good engraving results took some experimentation with tools and settings, but I only wasted a few 6"x6" acrylic sheets before I got it right. For the depth I needed, a 1/32" end mill did a better job than a 60-degree engraving bit, and I found that engraving the back side worked better than engraving the front.

I wasn't quite sure how I was going to mount the servo, so I started by cutting a disc from 1/16" black G-10 Garolite - basically printed circuit board material without the copper. I did this part early on and made a cutout for the small servo I was using, but broke that servo and had to use a larger one that wouldn't fit the hole. I'd intended to use standoffs to mount the disc to another disc, or to the bottom of the housing, but somewhere along the line I discovered that it fit snugly at the bottom of the end cap and that I could hot-glue the larger servo directly to it. This turned out to be good enough, and actually made it easier to align everything later on.

Note the complete lack of use of the mounting holes

The build process took an evening or two of design and PCB layout work and most of a weekend of building, coding, and testing. With the exception of the green LEDs (the ones I had weren't bright enough), the PCBs, and, of all things, a simple toggle switch (why didn't I have any of those?), all of the parts and materials were already available in the shop.

Some final tweaking was done in the RV on the drive to Nevada. Of particular concern was the need to get the servo and map disc aligned. To this end I wrote a self-test sequence that would rotate the pointer to the leftmost road, wait a couple of seconds, and then rotate to the rightmost road, all while cycling through all of the LEDs on both arrays. This made for a nice start-up demo and let me easily adjust the disc to match the servo.

Finished display in operation

Calibration of the map requires three elements: the map center coordinates, the compass angle of the first street, and the scale of the map. The first I got from Haggis at Burning Man Earth and was well-known in advance since the entire city is laid out around a marker spike driven at that point. The second wasn’t explicitly stated on the map I had, but I made an educated guess. The last was the least certain, but again I made a guess and got it pretty close. I refined my guesses using readings from a handheld GPS receiver once I was on the playa.

The indicated position was still off a bit in some parts of the city and I never had the time to track down the source of the error (perhaps some non-linearity in the servo’s response?) but everywhere it was within half a block, good enough for basic navigation. If I’d had time to add the planned LCD character display it would have been easier to debug.

Responses to the gadget ranged from the jaded but polite (“Is that a playa compass? Cool.”) to the… ah, ecstatic (“Ohmygod that is so &%@#ing AWESOME! YES! Can I take a picture? I LOVE it!”)

Ooh... shiny!

The source code is full of unfinished and unused junk and the board layouts were quick and dirty, but both are available here (C source for CodeWarrior, schematic and board layout in Eagle PCB). I've also got several extra sets of boards on hand - I don't want money for them, but I'll consider on-playa trades for food, shiny objects, or what have you at Burning Man this year!

Parts sources:

Digi-Key for processors, LEDs, and such
Strike Models for servos
Delvie's Plastics for fluorescent cast acrylic
McMaster-Carr for Garolite sheet, screws, and end mills
Argent Data Systems (i.e., from my own warehouse) for the GPS receiver
Orchard Supply Hardware for the ABS sewer pipe cap

Eye photo courtesy of Flickr user Monkey Boson (CC-attribution license)

SugarSync disaster

2010-08-09T12:29:00.001-07:00

It's not often that I have such a bad experience with a product or service that I feel like I need to write about it, but I'm downright angry with SugarSync. I set up this service several months ago to keep files (source code, business documents, and reference materials mostly) in sync between my home desktop, office desktop, workbench, and laptop. It seemed to be working OK at first, but things got progressively worse as time went on.

Here's the shared folder where I keep my Quickbooks files:


Argent Data Systems (from Jupiter) (Backup Apr 04,2010  06 26 PM).QBB
Argent Data Systems (from Jupiter) (Backup Jun 05,2010  06 40 PM).QBB
Argent Data Systems (from Jupiter) (Backup Mar 01,2010  08 04 PM).QBB
Argent Data Systems (from Jupiter) (from Workbench).QBW
Argent Data Systems (from Jupiter) (from Workbench).QBW.ND
<dir> Argent Data Systems (from Jupiter) - Images
Argent Data Systems (from Jupiter).QBW
Argent Data Systems (from Jupiter).QBW (from Workbench).ND
Argent Data Systems (from Jupiter).QBW.ND
Argent Data Systems (from Jupiter).QBW.TLG
Argent Data Systems.QBW.ND
Argent Data Systems.QBW.TLG

Keep in mind that I only have Quickbooks installed on one machine, so these files have never been opened or locked on another PC. Yet the files show up like they were edited in multiple places at the same time and the service couldn't resolve the conflict.

Much, much worse is what it did to my source code. I'd work on a project, come back a few days later and edit some more, and then find out that when I'd opened it the second time it had synced an old copy from another PC and I was editing that one. I've had to spend a lot of time with a diff utility trying to merge the changes.

Their support is worthless. All I can get out of the SugarSync people is that it's working as designed and making duplicates of locked files. Yet somehow it also manages to do this with files in my music collection that haven't been edited since 1997. It's also truncated photo files and made them unusable immediately after they were synced.

It looks like I essentially paid $99 to have an application trash my files in insidious ways. Avoid this service. I still need file sync, so I'm going to look into Dropbox or another competitor, but I'm very unhappy with how this turned out.

Cuyama Balloon Launch

2010-06-20T16:25:00.000-07:00

Just got back from a very successful high-altitude balloon launch. The original intent was just to prove some hardware and software modifications prior to a bigger upcoming launch, but at the last minute I decided to fly a camcorder in addition to the tracker payload. I put together a housing for the camera yesterday in about 10 minutes, milling out a chunk of foam on the MDX-20 and taping on a piece of scrap polycarbonate for a window.

The kids and I left home around 6:15 this morning and set up in a field by Cuyama Elementary around 7:30. We had some ground equipment hiccups - my netbook (normally good for 4-5 hours on one charge) was totally dead, for starters. Apparently either the serial adapter or the USB GPS receiver I'd plugged in the night before had kept it from hibernating properly. My TH-D7 also refused to turn on, despite having been on the charger all night.

The nuvi 350 and Tracker2 combination was working just fine, though - the only deficiency being that I hadn't set it up to be able to see the balloon's altitude. The D7 provided that, so long as it was plugged in to the car, so it wasn't a major problem.

Launch was at 7:45 in very light winds. It was immediately clear that the balloon was rising more slowly than planned - I think I miscalculated when setting up my calibration weight. The ascent rate was about 400 feet/minute rather than the planned 1000 feet/minute. This pretty much threw my predictions flight path predictions out the window. We drove out to Mettler anyway and stopped there to see what it would do.

When it looked like the balloon was going to keep heading east at 50+ MPH, I decided to take 138 out to 14 and hope that it'd make it over the mountains. Before I made it to 14, though, the balloon turned completely around and headed west again. We circled all the way up to 58 and were somewhere between Tehachapi and Arvin when the balloon burst. Bill Brown, WB8ELK, called me at about this point to provide his landing prediction.

Rod, WB9KMO, had joined in the chase not long after the launch and was first to the landing area - which turned out to be only a few miles from where we'd stopped in Mettler. We met up with him about a mile from the last APRS fix, and followed that to within 1/4 mile of the landing site. I got about 50 yards from the car before I spotted the foam payload housings and the remains of the balloon in a plowed field.

Everything was intact, and I got about 2 hours of video from the Flip camera. Not enough to capture the burst and impact, unfortunately, and it spins about as much as I'd expected, but for a 10-minute job I can't really complain.

The maximum altitude reached was 113,876 feet - not too bad for an 800-gram balloon. Payload weight was about 350 grams, most of which was the camera. The lowest recorded internal temperature was -19 Celsius, and the lowest pressure was 381 Pascals. Total flight duration was about 3 hours 20 minutes.

This whole thing involved rather more driving than I was expecting, but I'm very satisfied with the results. The updated tracker firmware performed flawlessly, the GPS receiver worked as expected at high altitude, it withstood very cold temperatures over a much longer than expected flight, and the lighter, less tangle-prone 16" rubber duck antenna proved to be more than adequate, even at 500 mW.

Video to follow shortly.

Balloon Launch

2010-03-23T10:39:00.000-07:00

Just launched a new balloon payload this morning. As I write, it's headed for Point Arguello at 16,000 feet. More info here later. Above is what the payload looked like the other day during testing.

http://aprs.fi/?call=N1VG-11

The payload is a custom board with an OpenTracker+ RT series tracker, temperature and barometric pressure sensor, SRB MX146LV transmitter, two CR123A batteries, a USB interface for configuration, and a Prolific GPS receiver (not the one pictured here). It's all sealed in 2" heat shrink tubing. The temperature just reached 1C, hopefully it'll stay warm enough.

Standalone MON08 Device Programmer

2009-10-08T14:22:00.000-07:00

Abraham Lincoln once said, "Give me six hours to chop down a tree and I will spend the first four sharpening the axe." In that spirit, I spend a lot of time building and refining the tools I use. So far, I've never regretted a minute of that effort, regardless of how much of a pain it was at the time.

My packing bench automation system is probably the best example of that, and I'll devote a post to it some other time, after I've added a few more of the features I've got on my list. But here's what I've been working on for a good portion of the past week:

It's a prototype of a standalone device programmer for Freescale HC08 microcontrollers, like those used in the OpenTracker+ and Tracker2. It's shown here with anMC908JL16 processor for the OT1+, which is presently the only thing it's set up to work with.

The hardware required to connect to an HC08 is actually very simple. I built my first programmer (way back before the OpenTracker 1) with parts I found in my junk box. I later upgraded to a board I bought from an outfit in the Czech Republic, and eventually to a USB pod from P&E Micro, of which I now have roughly a double handful thanks to package deals on development kits, freebies from Freescale, seminar handouts, and so on.

But all of those have required the use of P&E's programming software. Fortunately it's available for free, but they don't make it easy to find, and more importantly, they don't want you using it for automated production programming. For that, you'll need one of their $500 or $900 gadgets, or a nicer ($1200 + programming algorithms) system from one of their competitors.

I've never bothered, because with some creative use of a keyboard and mouse scripting tool I've been able to reduce the programming process to a single keystroke. Programming takes 30 or 40 seconds, much of which is avoidable overhead caused by P&E's software. It's a good job for a temp, and when the kids are out of school for the summer I can put them to work building up a stockpile of programmed MCUs.

Still, it's far from perfect. It could be much faster, and on occasion it'll choke and require some attention from a trained operator to get going again. More importantly, it requires a PC and it isn't something I can easily send off to a contract manufacturer. I'm making a major effort right now to reduce all of the post-assembly programming and testing operations to automated, standalone processes that can be easily run by anyone with minimal training - i.e., put the board in the programming fixture, press a button, and get a pass/fail result and maybe a test result printout on receipt tape.

Since I really need several of these things, and the $500 units aren't exactly what I want anyway, I decided to spend some time doing it myself. It's meant a few days at my workbench muttering and cursing - the programming process requires having the target processor boot a built-in program in ROM, then communicating with that program to load another program into RAM (which I had to write), starting that second program, and then communicating with it to actually do the erasing, programming, and verifying. And the one I/O pin you're guaranteed to have access to is not connected to any serial hardware, so it's all bit-banged. That tiny program, roughly 200 bytes, required several hours of coding and debugging. But the worst is over, and it's up and running now.

The unit shown above programs and verifies an OT1+ MCU in roughly 8 seconds. Pop the MCU in the socket, hit the button, and wait for the 'done' message. Lather, rinse, and repeat. P&E's "high speed" algorithm takes 20 seconds just to do the program and verify operation, not counting algorithm loading and user interface overhead. I haven't put any real effort into speeding up the process yet, but I think I can cut it down to 4 or 5 seconds without much trouble.

The code is still immature and doesn't elegantly handle error conditions (it just stops and displays a message, with no automatic retries or anything) but I've already added one useful feature I haven't seen elsewhere - it automatically detects when you've removed the target MCU, so it can clear the 'done' message and avoid any possible confusion when the operator gets distracted and forgets whether the chip in the socket is really done or if they just haven't pressed the button yet.

Total cash outlay for this prototype was roughly $10, including the perfboard (I hate FR-2, but the FR-4 perfboards were $30 and weren't the right size), button, ribbon cable, and connectors. Everything else I already had on hand. The green PCB is an AW-PROTO board, one of several dozen I had made for in-house prototyping of circuits build around the MC9S08AW series MCUs. I've got a big pile of those 16x2 backlit LCD modules, probably from when Electronic Goldmine or someone had a clearance sale. I actually got it mounted upside down, but I decided it doesn't really matter which way the board faces.

When the device is more mature, I may offer it as a commercial product. Might not be worth the effort required to document and support it, though. But in any case, I ought to be able to distribute a few to my overseas resellers to handle re-flashing of corrupted OT1+ and Tracker2 processors, and I'm looking forward to integrating it with the new automated OT2m test fixture that's in the works now.

OT2m Version 2.0

2009-09-21T12:03:00.000-07:00

Pictured above is the first hand-assembled OT2m prototype with the new version 2.0 PCB. It's working well, but I think I'm going to make one or two small tweaks before it enters production.

The most obvious difference between version 2.0 and version 1.0 is that the demodulator is a CML Micro MX614 instead of the NJM2211 from NJR. Getting consistently good performance from the 2211 has been a pain. The switch to the MX614 is going to mean a cost increase of at least a few bucks, but I think it'll be worth it for the improved RX performance and decreased testing and tuning burden.

Less obvious is the addition of ESD suppressors on all external connections. I have yet to attack it with my ESD zapper, but it should be considerably more resistant to static discharge than the previous version. I won't guarantee that it'll survive a nuclear EMP, but it should tolerate some rough handling. The ESD suppressors also introduce some capacitance that should help improve RFI immunity, though that's never really been a problem with the 1.0 board and its existing inductive filtering.

The power supply section's be rearranged a bit and has proper reverse-bias protection now, that also protects the VN920 solid state relay - correcting an oversight in the last version that resulted in a couple of accidental magic smoke releases. D11 is undersized in this picture because I forgot to order the proper part.

The solder jumper SJ1 is there to bypass the reverse bias protection. This is in case you want to power the unit through the high-current pads and still want the supply voltage measurement to work.

What you can't see under that pretty black solder mask is that the board routing has been completely redone, mostly by hand. Eagle PCB's new follow-me router makes it much easier to lay out traces manually and resulted in a better arrangement of components, especially in the sensitive audio input section. The most critical traces are 14 mils wide there (version 1.0 was mostly 8 mil traces) and only a few of the shorter traces are under 10 mils anywhere.

This batch of boards was also made with twice as much copper - 2 oz per square foot, versus 1 oz for the version 1.0 production boards. This means more power handling capability in the solid state relay section in particular. The prototypes were done with a lead-free HASL finish, but I've had the production boards quoted with electroless nickel / immersion gold like the OT1+ boards.

The only other real change in this version is that the (never used) FRAM expansion has been removed, and those four I/O lines have been rerouted to the MON08 header at the front of the board. This should make it easier to wire up a keypad to go with an LCD display if I can ever find the time to finish the coding for the user interface.

Absolutely no firmware changes are required for the new board. Transmit audio is still generated by the processor, not the modem IC so it's still capable of 300 baud or PSK31 output. There's also some extra filtering on the audio output.

Decode performance is quite satisfactory. With the WA8LMF Track 2 test, it decodes 987 packets. The best I've heard reported for any other TNC is 970 for the uTNT. My KPC-3 scored 967. The highest ever recorded, to my knowledge, was 991 for an early Tracker2 connected to the output of the same KPC-3's TCM3105 chip. I'd have considered the TCM3105 for the new T2 board, but they've been discontinued for years.

It looks like the OT2m is going to be out of stock for a little while. The existing stock is enough for maybe two weeks at this rate, and it's going to take at least twice that long to finish testing the new board, make some minor tweaks, source all of the new parts, and get production started - which means new pick and place programming and a new solder stencil. I think six to eight weeks is more realistic.

I'm also going to have to have more enclosures produced, which doesn't usually take that long, but I've been a little unhappy with the consistency of the last batch or two from my current supplier. I've got a small pile of case pieces that just won't fit with the others. It wastes parts, and wastes time when you get an out-of-spec cover or end panel and have to disassemble it again.

Accident

2009-04-23T17:45:00.001-07:00

Just my luck... Car accident exactly on the city line. Police and CHP are still trying to sort it out. No one hurt, thankfully. Car's going to be out of commission for a while, though.

Vacuum Molding

2009-03-06T21:34:00.000-08:00

I picked up a vacuum former the other day for under a hundred bucks, figured I'd see if I could put it to use making radomes and such, or at least to prototype packaging. I ordered a bunch of different plastics from McMaster-Carr, and Charlie and I spent the evening molding shapes out HDPE, ABS, PETG, Acrylic, and (unsuccessfully) PVC. Haven't tried the polycarbonate yet. I'll post more of my results later, but shown above is the most functional thing we've come up with so far.

We used Jeff (the same scarab carving that served as a test subject for the MDX-20's piezo scanner, 3-axis milling, and urethane casting) to make a mold in 1/32" FDA-approved HDPE and then mixed up a batch of Jello Jigglers and cast a Jello Jeff. Shown above are the original, vacuum-formed mold, and Jello casting. Jeff's got a bit of an undercut around the base, so de-molding the Jello is tricky. Still, it worked reasonably well.

Spider

2009-02-03T10:56:00.001-08:00

Found this guy on my office floor this morning. I hate spiders. Didn't squish him, though. Kept him around long enough to check him out under the microscope and then dumped him outside. The camera on the new boom microscope can't get any lower magnification than this - I had it on the 1x objective and 0.5x reducer. Works well for PCB inspection and assembly, though.

Working on commercial tracker stuff today, and trying some tweaks to my SSTV gadget to try to make it work reliably with the new camera modules. They're driving me nuts, and I think I may have destroyed at least one of them.

Finding a New Bank

2009-01-05T10:55:00.001-08:00

When I set up my business checking account back in '04, I decided to go with a local bank - Mid-State Bank & Trust - on the theory that they'd be more likely to provide decent customer service. I'd had bad experiences in the past with both Bank of America and Wells Fargo, and I'd vowed that Wells Fargo in particular would never get another dime of my business. (The reasons are numerous - look up their class action lawsuits and take your pick.)

Some months ago Mid-State was acquired by Rabobank, and I'd hoped that being part of a big multinational bank might improve some of their online services; the website had always been terribly clunky and difficult to use. Alas, it's gotten far worse since then. I can no longer make payments on my line of credit, the system won't work with Firefox, and doing the most trivial of tasks is frustrating.

Worse, their service has really gone downhill. I'm currently missing a wire transfer and despite promises to track it down, I've heard nothing. It's a common pattern - call them up with a problem, they promise to look into it, and then nothing. I'm also missing mailings from them, important stuff like a routing number change that ended in me having to destroy 500 unused checks. And every time I send a wire transfer, the confirmation email comes from (and the return receipt goes to) a domain held by a squatter. Rabobank won't acknowledge the problem - like maybe they don't think that could be a massive invitation for phishing.

So today I decided to contact a few big banks with the same simple set of questions - can I make international wire transfers through your online banking system, can they be in foreign currencies, and what's the transfer fee? How the banks respond to the message (sent through their online contact form) will be as important as the actual answer - I'm tired of dealing with a bank that won't get anything done unless you park yourself physically in a branch.

I'll update this as it progresses, but here are the results so far. All questions were submitted at around 10:00 AM on Monday, January 5.

Union Bank of California
Immediate auto-confirmation by email promising response in 1 business day.

Received an email at 2:30 PM stating that online wire transfers are possible and to call a representative.

Called 800 number at 4:10 PM, got a recording (in English and Japanese) telling me to leave a message for a call-back within one day. Left a message.

Got a call back at 10:00 AM the next day seeking more information to direct my call. Was promised another return call within 30 minutes. Nothing yet, two days later.

WaMu
Got a response at 5:54 PM on Wednesday. Looks like a form letter pieced together from several canned paragraphs, not all of them quite relevant to what I asked. Wire transfers must be made from a bank; no response to the fee inquiry.

HSBC
Email response came in on Wednesday at 7:09 PM.

Called toll-free number (it has a 'Z' in it!) and spoke to a very friendly rep after navigating a reasonably short voice menu. Found out that they offer $15 wires (incoming and outgoing) and several currencies, and that they have an option for 5 free transfers a month. Also found out that I can't open an account because there's no branch close enough and they have to make a site visit. I was very pleased with the customer service, but it unfortunately it does me absolutely no good!

Wells Fargo
Got an email response at 11:53 AM on Tuesday. Wire transfers are available through their Commercial Electronic Office. Got a URL (no fees listed that I can find, mostly fluff and a lot of clicking to get a few nuggets of information) and a phone number.

Called the number provided and got a human after a short recorded announcement. I thought this was a good sign at first, but then it turned out the number I'd reached was only for password resets and token reassignments. The poor guy was confused and didn't seem to know why that number would have been given to me, but after a couple of minutes of awkward silence while he conferred with his team lead by IM he got me another number to call.

This turned out to be the main catch-all customer service number, which dropped me into a voice menu system. It kept insisting on an account number to speak to a banker, but after a few tries it gave up and transferred me anyway.

The next person I spoke to (after a hold of a couple of minutes) couldn't talk to me if I wasn't a customer, and put me on hold for a couple minutes longer while I was transferred to someone who could.

At this point I finally got some questions answered. Wire transfers can be done online for $15 in numerous currencies, and incoming wires are $7.50, but there's a 6-month waiting period before you can enroll. Until then I'd be stuck doing $30 transfers from a branch.

The fees are acceptable and they seem to offer a broad selection of services, but the 6-month delay would be hard to swallow, and what I went through trying to find this out tells me that Wells Fargo is still the same bureaucratic hell that I remember.

Bank of America
1:30 PM - Got a form letter response advising me to call the wire transfer department. Called, got a voice response system. Got to a live operator, was informed there's no online wire transfer option. Outgoing wires are $45, she didn't know incoming rates or currency exchange fees.

Verdict

Of the 5 banks I contacted, HSBC is the only one that seems to offer any real improvement over Rabobank in terms of fees and customer service. And it's the only one that won't take me on as a customer. Union Bank of California could still redeem themselves by calling back with the information I requested, but I'm not holding out much hope at this point.

I'd be happy to pay travel expenses for an HSBC rep to come up here and make the required site inspection, but alas, I don't think that's going to happen.

Looks like I'm stuck with Rabobank for now, unless another option presents itself.

Update

Things are getting even worse with Rabobank. I submitted a payment yesterday on my business line of credit - used to be you could manage it directly and it worked pretty well. Now, to make a payment, you go to 'Messaging' and select the 'Line of Credit Payment' form letter. Apparently they print that out and enter it manually. Only this time they took the money from the line of credit and put it in checking.

So this morning I started Round 2 of the bank search, and started checking with local banks instead of the big ones:

Santa Lucia Bank
Santa Barbara Bank & Trust
Community Bank of Santa Maria
Heritage Oaks Bank
Mission Community Bank
Los Padres Bank

Only those last two don't have so much as an email address on their website, so I'm going to have to call or visit in person, and I don't think there's much hope of them having online wire transfers if they don't even have email. Community Bank of Santa Maria sent back an out-of-office response, so at least there's one person there with email. When she's in.

Space Station Parts

2008-12-03T10:18:00.000-08:00

Went shopping for furniture at a local surplus warehouse and wound up buying some old ISS hardware. Got a good deal, but I don't know what I'll do with them - they're not even compatible with my space station.

DHL

2008-10-30T22:29:00.000-07:00

I've always liked DHL. They've always been great when it comes to delivering stuff in a hurry to odd places all over the world, even when being shot at. When I needed a domestic courier for overnight packages, I went with DHL because I was already using them for import and export shipping, and because I could get really good prices on prepaid shippers through Costco.

Lately, though, I'm having second thoughts. For quite a while I used their overnight services with no major problems - the worst was a rural delivery that got lost for a few days. When they moved the cutoff time for shipments from 4:45 to 3:45 it was tolerable, if annoying. But several weeks ago, I discovered that two days after dropping off a couple of urgent packages at the local depot well before the cutoff, they hadn't even been removed from the drop box in front of the depot!

Apparently something like half of their drivers just walked off the job. After pleading with the woman at the desk for about 10 minutes, I finally got her to give the packages back, since they weren't going to make it out that night and one of them absolutely had to be delivered the next day. I had to carry that one over to UPS myself and pay about $50 for UPS Red next-day shipping. Fortunately UPS has a much later cutoff time.

I never got my money back on the wasted prepaid shippers. They've never made good on any delivery guarantee, for that matter. I've filed a couple of claims and never got a thing out of it.

The worst was last week when I got a call from a customer who'd ordered a part to be delivered to their hotel room while they were briefly in the country on business. It hadn't shown up on time, and when I called DHL to inquire about it, I was told that since it was outside of a major metropolitan area they couldn't provide next-day service. Ok, I thought, two days should still be plenty. Nope - turns out that they don't even try, they just hand it over to the post office. Estimated delivery time on this 'overnight' package? Eight days! For under $5 I could have handed it to the post office myself and had it there in two days.

Turns out DHL is scaling back their US operations. I'm sorry to lose what was, for a while, a very attractive shipping option. I shipped a lot of stuff crammed into reasonably priced flat-rate mailers. Guess I'll have to work on some UPS or FedEx options.

I think it's worth mentioning that the USPS does an awesome job about 99.6% of the time. Even after all of the rate increases, you can still get a 1 lb package coast to coast in about two days for around $5, even to remote rural addresses. I've shipped thousands of pacakges by first class and priority mail, and they've lost or seriously delayed maybe half a dozen. The local clerks deserve some credit, too. Mario, Dave, Esther, Lynn - you guys are great. Edgar - you're new, so I'll cut you some slack.

SARCity

2008-10-14T09:54:00.000-07:00

A couple of weeks ago I volunteered to help out with a session on APRS at SARCity, an annual search and rescue conference in Barstow. I'd actually been to SARCity twice before, as an Explorer with the Santa Maria SAR team, so I was looking forward to seeing what had changed in the 15 years or so since my last visit.

Originally the class was supposed to be on K9 tracking, but thanks to some cancellations I wound up doing the whole 90 minute session myself and had the focus of the class shifted to general APRS use for SAR - I'm really not a dog person and didn't have much to show in that area.

Byonics and BigRedBee gratiously loaned me examples of their latest integrated tracker/transmitters, and I tried to keep the talk vendor-neutral. I had one of the first prototypes of my transceiver package there, but it's programmed for 12.5 kHz channels and won't tune 144.39 Mhz, so I didn't have it running as part of the demo. The final, 5 kHz/6.25 kHz radios are due in this week - I'll try to get something posted on them soon.

The class went pretty well, I think. I managed to run a bit over my time limit without really looking at my talk outline. This is probably the third or fourth time that's happened - I think I need to learn to just put the outline away once I'm satisfied with my slides and know what I want to talk about.

In all, the weekend was a blast. Surprisingly, I didn't see anyone I recognized from the Santa Barbara County team. Which was probably just as well, I suppose. There are some great people on that team, but I'm still bitter about how my association with the team ended and there are a couple of people I'd rather not have to deal with. I can't even write about it without getting angry all over again, so I'm not going to try to explain.

It was very gratifying to hear from members of several other teams that they thought I had something valuable to contribute to SAR, though. I've been invited back to talk again next year, so hopefully next time I'll have a lot more to demonstrate and I'll be able to do some more hands-on exercises.

Maybe I'll be able to overlap it a bit with the GIS track put on by ESRI - from my motel room in Barstow I was able to hack together a new output module for the Tracker2 that produces the same format as the Thales radios they had already interfaced to ArcMap, and on Sunday morning we were able to successfully plot APRS stations. ArcMap/ArcView/ArcGIS and that whole family have a steep learning curve and a hefty price tag, but apparently ESRI has some sort of grant program for SAR teams, and they're so far beyond the usual mapping applications most teams use that there's really no comparison. Assuming you've got a ton of computing power and a trained operator, anyway.

Croatia

2008-08-12T17:26:00.000-07:00

Wow - I'm way behind in my blog postings. I'd better start catching up now or I'm never going to get it done. I guess I'll start with my vacation in Croatia.

I flew to Dubrovnik by way of LA, Frankfurt, and Zagreb on June 18th. Arrived at the apartment (just across the street from the right-most tower in the picture) a little before midnight on the 19th. My friends Noelle and Rachel arrived separately on the 20th, from Iraq and Florida respectively.

The old city is absolutely beautiful. We spent a day visiting all of the local museums, another island hopping in the Elaphiti Islands, took a day trip to Mostar in Bosnia, went horseback riding, attended a very touristy 'authentic village dinner' party, went on a scuba trip, and after Noelle and Rachel left on the 27th, I made a day trip by myself into Montenegro to see Kotor and Budva. The Bay of Kotor is gorgeous, but Budva is way over-touristed.

A couple of chance occurrences on the trip happend to contribute to my decision to leave my day job when the vacation was over. First, the guy seated across from me at the dinner party in the village turned out to be the former head of research for a major water utility in the UK - and had experimented with some of the same approaches we were working on in our project, and abandoned the effort because of the same problems that have always made me doubtful about our prospects for success. And over a bottle of Havana Club back in the apartment, Noelle described her personal experience with the Army system we were in the process of writing a proposal for. Turns out the system was an even bigger boondoggle than I'd guessed. And something she mentioned about another, entirely unrelated program, turned out to be directly relevant to what the company later tried to convince me to stay on to help with.

I had a 7-hour layover in Zagreb on the way back, and a local OpenTracker user picked me up at the airport and took me out for a beer. I found out a little more about commercial use of my trackers in the country, and maybe even got myself a legitimate business expense deduction for part of the trip.

I'll post pictures to my Flickr account when I have time, but I think that's enough for tonight.

More Machining Fun

2008-06-12T20:40:00.000-07:00

Here's the scarab I mentioned before - I scanned the original with the MDX-20 and cut a new one out of machinable wax. It was finished with a 1/16" ball-nose end mill, which did a surprisingly good job of reproducing small details. It's also a lot more resistant to breaking than the smaller, more expensive tools I'm learning to use. So far I've broken two 1/64" end mills, both in their first 60 seconds of operation.

Here's another experiment. It's a model of Mount St. Helens, based on USGS digital elevation models. I'm sure there must be an easier way to generate stereolithography files from DEMs, but for this test I had to make a VRML file and convert it to STL format using an evaluation copy of Rhino.

I still haven't had much opportunity to mill PCBs with the machine, but I'm still finding other useful things to do with it. Today I fabricated a replacement lens for my Maglite out of Lexan. I figure that saved me at least $2. Or rather, it would have if the original lens had actually been broken. But at least I've got a spare, just in case.

Water, Water, Everywhere

2008-06-12T20:13:00.000-07:00

I suppose it can't quite compare with the flooding in the Midwest right now (we were in Des Moines for the 1993 installment, and I hear it's worse this time) but we had quite a mess here over the weekend. The hot water hose on the washing machine burst on Friday afternoon, and fortunately I was home at the time, but I was working upstairs and didn't discover it for half an hour or so.

By that time the water was about two inches deep in the laundry room and had run all the way through the office, under the door, and down the driveway. I got the water shut off and started a siphon with the garden hose. Once that was going I grabbed the wet/dry vac from the garage and started slurping up five gallons at a time and dumping it outside. Took two days for my back and leg muscles to recover from that, but it got most of the water out.

Tory made it home about then and started making phone calls while I continued damage abatement. It took the water damage cleanup people three or four hours to show up, and we spent that time continuing to haul stuff out of the office and storage area while Charlie worked the vacuum, extracting as much water as he could from the carpet.

For the next five days that part of the house was sealed off, full of blowers and a giant dehumidifier. The temperature got up to about 105 F in there, so I didn't get a lot of hardware work done over the weekend.

In the end, the damage wasn't too bad - maybe a hundred bucks worth of packing materials ruined, some cables destroyed, and a bunch of camping and emergency gear made very soggy.

The lost time is the biggest inconvenience, I suppose. That was supposed to be my last free weekend this month - this weekend we're going to Magic Mountain, and I'll be in Dubrovnik for the two weekends after that.

It's over!

2008-05-22T21:56:00.001-07:00

Hamvention 2008 is done! Dayton is my most stressful annual trip by a wide margin. This year went fairly smoothly, and I think the display was the best we've had yet. Jason did a great job putting together the nüvi / T2-135 display and it drew a decent size crowd.

I was definitely more busy this year than last - I got out of the booth a couple of times on Friday and managed to see at least some of the other exhibits, at least in passing, and even had time to eat a cold hot dog over the course of about an hour. Saturday was a little more hectic, and I don't recall even getting a bathroom break for about eight hours, and no food at all. Can't say I really noticed until it was over, though.

Financially I think it was probably a wash, as usual. Between booth space, airfare, hotel, shipping, and so forth it's hard to turn much of a profit at Dayton, but it's worth doing for the exposure.

I'm still about a hundred emails behind thanks to the trip, and I've got a ton of other stuff to get done this weekend. I did finally get a chance to try making a PCB with the MDX-20 today, though. And broke my first tool in the process - not one of the $6 ones, either. It was my sole $48 1/64 inch end mill, of course. I had it cutting just a bit too deep and a bit too fast, and it lasted about 5 or 10 seconds. Did a nice job right up until it snapped, though!

Somehow I wound up with a bunch of 0.062" Garolite G-10/FR4. It's the same stuff the PCB substrate is made of, but colored. I cut some shapes out of one of the black sheets and they look cool, but they seem to be very prone to scratching.

I'll have to pick up some more polycarbonate and play with that. I've only got a 1" thick slab, which is a bit more than I want to start with.

I got the scanner option running the other day, too. We put Charlie's little stone scarab carving in it and generated a model with 0.008" resolution. Took a few hours. I then had it cut a new scarab out of machinable wax. It came out pretty good, but I'm still learning how to properly set up roughing and finishing processes.

I even managed to make a useful production item with the machine. It took me a few tries, but I got it to do the required cutouts in the ABS end panels for the ADS-SR1 repeater. I have a couple hundred aluminum panels already fabricated and paid for, but I should be able to do the next batch in-house. It's amazing how much more mess a small amount of ABS makes, compared to the machinable wax. I think it must be a result of its electrostatic properties. It coats every surface in the machine, while the wax just piles up nicely to be vacuumed away.

New toy

2008-05-12T20:52:00.000-07:00

I'm totally swamped with Hamvention preparations, but my new Roland MDX-20 CNC milling mchine came in today and I had to try it out. It's been working great, at least since I figured out that one of my serial ports was bad and was causing the machine to try to throw chunks of wood at me.

Right now it's running through one of its sample files - a banana, which it's cutting from machinable wax.

Anyway, back to flyers and price lists and demo hardware!

Mila Rainof, 1980 - 2008

2008-04-26T20:26:00.000-07:00

No project updates this week, just a farewell to a friend. I met Mila through Tory - they were in the same draw group at Stanford and had been very close ever since. I didn't know Mila nearly as well, but she was one of those people whom it's almost impossible not to like, and news of her death came as a shock.

Mila was finishing her last year at Yale Medical, and was set to start her residency as an emergency room physician back here in California. She was struck by a car and killed while crossing the street on the way to her apartment last week.

My last email conversation with Mila was about trauma cases we'd both seen, oddly enough. She was on anesthesiology rotation at the time, which she said mostly involved jealously watching other people sleep.

What a horrendously unfair end for a wonderful, bright young woman who should have had a long and productive medical career ahead of her. It's been a week and still the refrain from Depeche Mode's Blasphemous Rumours runs through my head when I think about it. A sick sense of humor, indeed.

You'll be missed, Mila. The world is without a doubt a worse place without you in it.

Making Progress

2008-04-15T21:28:00.000-07:00

The simplex repeater project has been coming along more slowly than I'd hoped. That's been partly due to the difficulty in getting the software-based DTMF decoder working, but I think it's good enough at this point for a beta release at least. But mostly, everything else imaginable keeps getting in the way.

I've got what must be my tenth cold of the season. Charlie brought this one home. Fortunately it's not a bad one, and I haven't been totally out of commission.

I started buying parts for the first production run last Friday. Ran into two problems - first, the flash ICs are being phased out in favor of a new model. It's not the end of the world, since I made sure there were other parts out there with the same pinout that'd work. Trouble is, the new chip doesn't have one particular feature I'm using, and coding around it would take a bit of work. Adapting the code to an entirely different vendor's chip would take a significantly larger amount of work, and it'd probably mean a major rewrite of the SSTV encoder, which uses the same chip. Fortunately I found a good source for the old part, so I've got 500 on the way, due in on Friday.

The next problem was the switch. I designed around a model that I had several examples of on hand, and I was careful to make sure it was available from at least two other vendors. Only I didn't think to check on availability of the caps. Who would have thought that sourcing a stupid plastic cap of the appropriate size would be such an ordeal? I spent two or three hours hunting online and calling vendors. The closest thing I've found is too big to fit in the hole, and I'd rather not throw out a couple hundred custom-made end plates. I think I can modify the holes to widen them by about 1 mm without ruining the finish, though. Might have to move the switch back a bit on the next PCB revision to accommodate the longer cap, but there's tons of space for that.

No major hardware glitches with the PCB so far. The footprint for the flash chips is wrong, but it's close enough to work with a little care. I routed the external squelch input to an I/O pin with no interrupt function, which pretty much kills my power save scheme when operating in that mode, but if you've got an external squelch then you're probably using a mobile rig and have external power anyway. Besides, if you've got any announcement or ID timers enabled it's not going to be in deep power save mode anyway. Worst case, it'll mean 30 days of idle battery life instead of six months.

The prototype pictured above has a laser-printed paper label on it. It was my first attempt, but I think it'll do. I don't want to clutter it up with more text and graphics than necessary. I'll add a page to the manual with a quick reference guide on a strip to cut out and fold up to fit in the battery compartment.

The 10-mil Lexan graphic overlay on the production version will cost nearly as much as the case itself, at least to start with. Still, I think it'll be worth doing, and I'd like to get experience working with the material.

Oh, and after all of the component troubles, I was finally ready to get some work done on Sunday, but there was a fire in the lot of the packing company down the street from my office. It took out power to a good portion of the town, along with cable TV and Internet. Fired up the generator for a bit, but didn't get a lot accomplished.

Charlie's off at Outdoor School this week. I remember my own week there, two decades ago. I hope he has an easier time on the 9-mile ridge hike; the wind must have been blowing 50 miles per hour at the top, and was driving rain and hail on the day I made the hike. I think it was also uphill both ways in those days.

New Prototype

2008-03-18T21:57:00.001-07:00

The new Tracker2fc prototype boards came in late last week, and on Friday I built two of them and got one installed in a sample of a low-cost 5-watt synthesized UHF transceiver module. It's working great so far, aside from some minor mechanical fit issues. And I think maybe I broke the antenna lead on this sample, but the other one had the modem header installed wrong and would need some work to get the board to fit.

This system is the closest I've come to what I envisioned for the T2 a few years ago when I first started thinking about the OpenTRAC protocol and how a tactical SAR tracking system ought to work. A lot of that thinking was done on long walks through the woods at Vandenberg - I can remember where I was on the trail when I decided on certain critical features.

There's still a lot to be done before I can achieve that ideal, but at least it's a step in the right direction. The next big (and rather expensive) step is going to be getting the VHF version going. The vendor is sure they can do it, but I'm doubling their time estimates in my own planning. I might have samples to show at Dayton, but I'm not holding my breath.

I was planning to get some more debugging work done on the T2's support for the Garmin fleet management interface tonight, but when I do too much coding late at night I get wired and can't fall asleep for hours. And when I do sleep, I dream in C code and schematics.

Tomorrow I've got an appointment to check out some commercial spaces in the business park across from the airport. Things are getting too crowded here. One of the units is actually about twice the size of what I was looking for, but it might work after all. FTI needs to find a new office too, and since it looks likely that I'll be doing some consulting work with them on a regular basis for another year or two, sharing a larger place might be a good option - I'll be able to cover both without a lot of running around. FTI needs more office space and I need more warehouse space, so I think it'll work well. And if they leave town when the project is over, I can take over the remaining space or it can be split back into two units again.

I hadn't really planned on getting back into Air Force stuff again, but there's not really anyone else who knows the systems well enough to handle the modernization effort. And besides, there's a lot of satisfaction in knowing that my systems (ok, not solely my systems, but I put more work into them in the last decade than any other three people combined) are getting used on the Shuttle program, and maybe eventually Constellation as well - and knowing that we did on a shoestring budget what Lockheed Martin couldn't do for tens of millions.

Cat Tracking

2008-03-09T21:33:00.001-07:00

I've tested out one of the GPS data logger samples already on a trip around town, but I figured it was time to do something more interesting with it. Tory was out shopping and called to see if I needed anything, and since she happened to be right next door to the pet store, I suggested a small harness for the cat.

Turns out they had just the thing, from 'Outward Hound' - made for a small dog, of course, but it looked like it ought to fit. Apparently it's important for dogs to be able to carry cell phones these days.

I put it on Squeaky, and she had it off in under 5 minutes, without ever leaving the front porch. I tried it on Bella next, since she seems to be a considerably dumber cat. For a minute she'd only slink around backwards, but she eventually figured out that she could still move around just fine. She eventually wandered off and took a nap in one of her usual spots. I didn't see her again for a few hours. When she showed up on the balcony I didn't expect that she'd actually gone anywhere, but apparently she travels more widely than we thought. Looks like maybe she has some friends over at the retirement home. I'll have to try tracking her over a longer time span sometime.

Oh, I also got Robot 36 mode working on the SSTV encoder. The RGB to YCbCr conversion turned out to be not so bad after all, with the HCS08's hardware multiplier. The camera module itself continues to be a major source of frustration, thanks to undocumented timeouts and other odd behavior.

Slow Scan TV Gadget

2008-03-08T21:36:00.000-08:00

A few months ago, I started thinking about what I wanted to do for my next balloon launch. Getting live pictures back was at the top of my list, but I didn't want to commit expensive ATV gear to the launch and I didn't want to deal with lots of FEC and a high-speed data link to transport JPEGs. That got me thinking about SSTV. It's relatively simple, it degrades gracefully in the presence of noise, and it'd get a picture through fast enough to be useful.

I did some research and found that the Kenwood VC-H1 was pretty much the only compact, stand-alone SSTV device ever made. It was introduced at around $600, and still sells for around $300 on eBay on the rare occasions they come up for sale - they were discontinued some time back.

So I set out to build my own device. The first thing I needed to do was to figure out how the signaling actually worked and see if I could do it on the 8-bit microcontrollers I usually work with. Finding reliable information turned out to be a nightmare. Seems like everyone who's ever worked SSTV has felt compelled to put up their own explanation of how it works, based on everyone else's fragmentary explanations and misinformation.

Just finding exact line timing was nearly impossible. I found a site that showed line times to several decimal places, but it turned out to be the same inaccurate garbage presented in a different form. I finally got in touch with Jim Barber, N7CXI, and found out that he'd presented a paper on the subject at Dayton back in 2000, but hadn't gotten around to publishing it online. Turns out there were some quirks to the Scottie modes I was using that I'd never seen documented elsewhere. Once I had that, generating a test image was easy enough.

The next step was getting an image from a camera. I found a source of suitable digital camera modules - not high-end optical instruments by any means, but good enough and easy to interface, stupid communications glitches notwithstanding. Rather than build everything onto a development board, I started with one of my simplex repeater prototypes. It already had all of the hardware I needed, aside from a serial port.

I grafted the camera and a debugging serial port onto the processor using 30 gauge wire wrap wire, and soon had it dumping frames into flash memory. Getting the timing right to fill up the width of the frame was a little annoying, but I got it, to within a reasonable degree of accuracy. I also added a character generator to use the top 16 lines for text display.

The real challenge was getting it to do everything at once. It's got to start transferring data from the camera, storing that to flash every 256 bytes, reading back a line of data at a time (each line gets scanned 3 times for red, green, and blue), and sending samples to the PWM module every 1/38,400 second. Writing a page to flash takes about 3 milliseconds and it can't read while it's doing that. It also can't do line reads during the sync interval because of the idiotic line sequence in the Scottie modes.

It's some of the ugliest code I've written in recent years, but it works, at least for S1 mode. It's almost there for S2, but the faster scan rate is still causing problems. Once I've tackled that, I'm going to try Robot 36. I'm not looking forward to it -I'll have to convert on the fly from RGB to YCbCr color, with an odd interleaved chrominance subsampling scheme. I've got a few kilobytes to spare for lookup tables, though, and the HCS08 has a hardware multiplier. I'm sure I can come up with something.

Worst case, it'll have to wait for version 2. I'm working on a new design that'll have enough SRAM for a proper frame buffer, with an NTSC/PAL/SECAM decoder for external video input. The same hardware should work for a larger selection of digital camera modules. I'm going to have to learn some VHDL for the CPLD I'm using to tie it all together. Might also make the switch to a 32-bit ARM7TDMI processor. I was planning to use an Atmel part, but NXP has some really nice devices that are considerably faster for about the same price.

Almost Ready

2008-03-06T16:42:00.001-08:00

The contract manufacturer sent pictures this morning of the first panels of T2-135, OT2m, and OT1+ SMT boards. Looks like no major problems so far - hopefully I'll have them by next week. I've got a growing stack of orders for the OT2m - I've been able to keep up with T2-135 demand through local production, for the most part, but the OT2m is too complicated to be worth doing here.

We all caught the bug that Tory brought home - she and Charlie stayed home sick today, and I've got the sore throat and cough, but not quite as bad as those two. I'm hoping that I'll be over the worst of it by tomorrow - got too much stuff to try to get done.

I got the USB/Bluetooth GPS data logger samples today that Stephen picked up. He happened to be in Taiwan already, so I had him visit Progin's headquarters in Tainan to talk to them about a new project (not ham radio related, and I'm keeping it under wraps for now) and put in an order for some assorted samples for him to pick up as well.

They're cute little gadgets, and they seem to work well. Haven't got the Bluetooth feature to work with my smart phone yet, but that's probably more the fault of the phone. Used with a laptop they'd be good for APRS, but data logging is what interests me most. The software will output directly to KML format for Google Earth. If they'll do 3D tracks, they should be great for hang glider and paraglider pilots.

Picked up 600-odd OT1+ cases from the print shop today. Now if I can just get the sequenced axial component tapes back in stock, I can build up a stockpile of kits that might last me more than a few days.

A new Tracker2 board layout designed for internal use with a 5-watt data transceiver went out to the board house the other day. With luck, I'll have the boards on hand in time to build one next weekend.

House Hunting

2008-03-03T22:45:00.000-08:00

I'd intended to mention this in my first post, but had to run off to swimming practice before I got a chance.

After Tory moved in last year, it was obvious that the old house just wasn't going to be big enough for all of us any more. We'd been renting the place for seven years - about twice as long as I'd expected to be there. The real estate market was at its peak, and we decided we just couldn't justify buying a house. I'm very glad now that we didn't.

So we rented this house, and we'd planned to stay here for at least a few years. The house is big - probably a thousand square feet bigger than any place I've lived before. The master bedroom is huge, the kids' bedrooms are a decent size, and there's room for my office in the converted garage downstairs. There's an extra storage building (built to house a spa, but never did) so I've got room for my lab benches, server rack, helium tanks, dewar, and all that good stuff in the detached garage. I did finally part with Behemoth, my old VAX 6000-510 minicomputer that I'd had in the garage at the old house for so long. It found a new home at the Computer History Museum in Mountain View - maybe some day I'll go visit it.

All was good until a few weeks ago, when the landlady called. The house is owned by a trust - it was inherited by five siblings when their parents died. Apparently two siblings had already sold their shares to one of the brothers, and now another is faced with a big tax bill and wants to sell out as well. The brother agreed, but on the condition that he would buy the one other share as well and own the house outright.

They did give us the option to buy the house, but at a price that would have been more realistic a year ago, when the market was better and we hadn't had 10 months to find all of the little problems with the place - like the electrical conduit for the wiring to the office that wasn't done to anything remotely resembling code and had to be completely replaced when it corroded away. But the brother's willing to take the place as-is, so we're out of here in the next couple of months.

It's a buyer's market right now, but it's still California, and a decent 3-bedroom house anywhere near town is still half a million bucks. We found a place we like just a few blocks away that'd be great - not huge, but big enough, and with both a shop (with plumbing and 220 volt power) and a very clean detached garage. The price is still a stretch, though. At this rate I'm afraid we're going to be renting for a few more years.

Cables

2008-03-03T22:41:00.000-08:00

I just got my first batch of custom cables in from China today. I have to say I'm very happy with the results. I'll definitely be doing more business with this vendor. They were great about providing drawings and tracking all requested changes. A refreshing change after having my radio cable supplier just entirely give up on trying to understand what I wanted and sending me exactly the same thing as the last order.

I'm reading a book on dealing with Chinese manufacturers, and it warns about exactly this behavior. The new vendor is based in Taiwan, with production facilities on the mainland. I'm sure I could get a slightly better price going directly to the mainland, but sometimes it's worth the added expense of a middle man, especially when there's such a huge language and culture gap.

I'd keep my manufacturing domestic if I could do it even at twice the price, but I can't. Last time I got a quote on over-molded cable assembly from a US company, the setup alone was more than this entire order. There's actually a place in town that makes custom cable assemblies, but I think their prices start at about a hundred times what I'm paying now. To be fair, they mostly work in the nuclear power and aerospace industries.

XO

2008-03-03T20:30:00.000-08:00

I got my XO-1 today - the cute little white and green laptop from the much-hyped One Laptop per Child project. I'm not exactly blown away, but it's an interesting piece of hardware. I'd intended to let Allie be the first to try it out; what better way to test the usability of a device made for children than to give it to an 8-year old? After playing around with it a bit myself, I decided that maybe it would be a little too frustrating for her without help.

At the moment, Charlie's got it. He's been begging to try it out since I got it out of the box. I figure it should be much less of a challenge for a reasonably computer literate 12-year old. Sounds like he's either using the oscilloscope function or the recorder right now; I can hear him making noises and strumming his guitar.

The machine's definitely not fast, at least in terms of loading applications. The applications themselves seem to be responsive enough once they get started. The keyboard is just barely usable by adult fingers. The user interface is most definitely not the simple, intuitive system I was expecting from all of the hype.

Charlie just brought it back, apparently tired of trying to get around and find applications. I don't know what he did to it, but it was running very slow for a few minutes. I managed to close a few things and it's running better now. If just loading up several things at once is enough to bring the system to a crawl, I think that's going to be a problem. It's not immediately obvious how to exit from all of the programs.

I tried to close TamTam jam, but it says 'Keep error: all changes will be lost', and gives two options: 'Don't stop' and 'Stop anyway'. Not terribly informative.

The system seems like it's designed by programmers for kids who want to be programmers. I'm all for allowing tinkering, but it's like the highly nerdy and obscure humor in Futurama - great if you can fit it in for those who appreciate it, but only if it can be done without annoying those who don't.

Some day maybe I'll work on some long-range comm hardware for it. Would be kind of cool to come up with a portable HF / amateur satellite email gateway, at least.

Dayton

2008-02-29T08:16:00.000-08:00

My new ARRL card came in. I haven't really kept up my membership consistently, but I suppose it's worth it for QST - especially since there don't seem to be many other ham radio magazines around these days.

I tried to sign Charlie up at the same time, but their online form wouldn't accept 1996 as a valid birth year. It's not like 12 is an unusually young age for a ham - he's been licensed for over a year and a half already, and I was licensed at age 10, too. I'm sure the validation is only on the client side, though, so I'll probably just hack the form and make it accept it. I reported the problem but no one seemed particularly interested.

I emailed the application for the Dayton Hamvention booths last week, and as usual I've had no confirmation, and no one answers my messages. The ARRL, on the other hand, has been emailing and leaving phone messages about advertising in their special Dayton section in QST. I'll probably skip it this year - a 1/24 page ad is more than a month's online advertising budget for me. I'd rather spend the money on a nice eye-catching display for the booth.

It continues to amaze me that Hamvention can pull in millions of dollars and still be such an amateurish production. Their website is straight out of 1997 (and they've refused offers of free web design help), they're difficult to contact, even for those of us shelling out $1,700 for booth space each year, and when things go wrong, no one is accountable. Last year we were without Internet access (that we'd paid in advance for) for half of the show, and it cost us dearly in lost credit card sales.

They were blaming problems on an outside vendor, but they didn't even have the cable run to the booth until a day into the show - they claimed they'd lost the order. I'd specifically paid for wired access because I didn't trust their ability to get wireless working. At least we had working power - the year before, we didn't even have that when we got there. Nor did we have the table drapes that the website had promised - I had to fire up my broadband card and bring up the website before I was able to convince someone that it really did say that. The only compensation they've ever provided was a refund of half of the Internet access charge.

Hamvention will keep on going out of sheer inertia, I'm sure. Everyone comes because it's the biggest thing around, and at least from a vendor's perspective, if you're going to go to one show a year, Dayton's it. But at this rate I don't expect the show to ever get any better. I know a lot of volunteers put in a lot of work, but I really think they'd be better off handing the management over to a paid management service.

From my phone

2008-02-28T18:39:00.001-08:00

Time to see if my idiotic, infuriating Windows smart phone can be put to good use. This thing - a new Samsung model - annoys me to no end. It's a mediocre PDA and a lousy phone. The ergonomics are awful. The user interface is laggy, and while you're typing it has an annoying tendency to randomly jump to the address book. Oh well. I've attached a picture to see if that feature works - it's Allie after she fell asleep in the middle of a homework paper.

So it begins

2008-02-28T17:29:00.000-08:00

I don't think I've actually managed to maintain a personal webpage since about 1996. I'm hoping a simple wysiwyg blog will be easier to keep up with - especially when I can update by email.

The week started out badly, with the sewer backing up and both downstairs bathrooms and the laundry room flooding. The carpet got soaked in three places - two of them in the office, and one in the den. The plumber got the problem taken care of in a couple of hours, but cleanup took half a day and we've had fans running ever since, trying to finish the drying process. The whole house smells like wet carpet and carpet cleaner.

Time to take Allie to swimming practice. I'll have to try posting from my cell phone.