geolocation

GPS Logger Tomfoolery: Getting the GlobalSat DG-100 Working On a Mac (Successfully!)

One of my intentions this year is to track more of my movements and document them in photographic form. One of the downsides of the GlobalSat DG-100 GPS logger is that there is no support, at least not officially, for Mac users to retrieve tracking information, necessitating a trip to Windows and then back to get the photos matched up with the coordinates at which they were taken. Many have tried, and failed, to hack it in, and after spending a couple of hours today, I can now declare myself as part of those who have failed. But I came oh so close.

GlobalSat DG-100 GPS On WestJet

Spurred by Richard Akerman's writeup and screenshots of HoudahGeo for the Mac, and especially his sidebar comment about support for the GPS logger we both own, mixing metaphors like few have mixed before me, I dove into the swamp of programs and yak shaved until the cows came home. Or, rather, until an error message that I couldn't debug appeared on my Terminal screen. Cough. Here are the steps I took to get where I got to before giving up.

First, I downloaded the GPSBabel command line program and graphical interface, but not before spending a few minutes looking at the gpsbabel.org documentation. It's not clear from their downloads page, but you have to click through another link to get through to the SourceForge project page. SourceForge, despite improvements in their interface, is still not easy enough to use, and not easy enough to get a direct download link for a package (which I often need when at the command line using wget). That's another story. After downloading the Mac OS X package, and hopelessly futzing around with the command line supplied for the DG-100, I searched around a bit and found someone who had also tried GPSBabel with the DG-100 and found out that indeed DG-100 support wasn't built into the 1.3.4 release. They suggested checking out the HEAD version from the SourceForge CVS repository. If none of that previous sentence made any sense to you, consider yourself part of the blissful majority.

That of course meant compiling software. And what do you need when you compile software? A compiler! The compiler I needed was gcc, and seemingly the only way to get gcc is to install it from the DVD that comes with your Mac. People like me lose stuff like that. Not yet, in my case, as my DVDs are in a cabinet at my apartment, but having done most of the work at the office, they needed to be at the office. Good thing I work with Mac users.

After a couple of tries at installing gcc (I needed the SDK for Mac OS 10.4), I was able to compile a developmental version of GPSBabel. Somewhere along the line, it occurred to me that I didn't know how to access the USB port via the command line, that is, which argument to use. The command line suggested at gpsbabel.org recommended /dev/ttyUSB0, but there was no such 'device' on my Mac. I came across a forum post about DG-100 support for the Mac, which tipped me off to an open source driver, which has something to do with a Prolific PL-2303X USB-serial adapter on the DG-100. That got me closer.

(We break into regular programming to note that a "Jaako" posting in the forum was able to get the DG-100 working with his PowerBook, but that all the dates of the readings were from the fist day of 1970. Is that the same Jaako that went driving around Taiwan and reported it on Good Fishies, the blog of his and his incomparable girlfriend Cathy Wang's trip to Japan and China? If so, he got closer than I did. Now back to the thrilling conclusion.)

After installing that, and restarting my MacBook (along with the customary baby feline sacrifice), satisfied that my yak had been sufficiently shaved, I modified the command line slightly to look like the following: gpsbabel -t -i dg-100 -o gpx /dev/cu.PL2303-0000103D outputfile.gpx I get the following response: dg100_recv_byte(): read timeout

And that's where I'm left. Looking at the C code that does the work for the DG-100 with PHP-coder eyes, it's not clear what could be changed to make it work. Searching for the error message or the function name only gets me the C code or forum posts I've already looked at. Any ideas?

Time passes and Jaako reports in the comments on how he got the GlobalSat DG-100 working on a Mac. You'll need gcc to compile the C file, in which I've changed 3B1 to 0000103D. The software is GPL, so I distribute it under the same terms. Thanks Jaako for the pointer, and thanks to Mirko Parthey for the original work.

2008 New Year's Intentions

Three years ago, I posted my resolutions for New Years 2005, and updated two months in with my progress. This year, instead of resolving to do something, that is, committing to a change or continuation of something, I'll simply declare my intentions. That way I can be honest and won't feel bad about breaking a promise to myself. Regrettably, this isn't as clever as I thought it was before looking up the phrase 'new years intentions' in Google.

  • Start a savings and/or investment account and make regular deposits. Unexpected income used to go to debt. Now it will go to savings. I took a step towards this in December, and now with a real job, I can think more clearly about my retirement.
  • Fix Urban Vancouver.
  • Go on a real vacation where I don't check work email. At all. I even intend to write one of those very boring "I'm on vacation" autoresponder that everybody hates. I'm thinking a few days in Portland, then a few days on the Oregon Coast, with a day or two to document my adventure when I get back. I haven't decided when, but May or July look right.
  • Continue bookshelf sustainability. So far so good, though with Christmas came 4 books, meaning I must now give 4 away.
  • As a belated yet environmentally-friendly protest of TransLink's fare increase, I intend to bike to and from work each weekday for a month. I would buy a one zone pack of tickets and a two zone pack of tickets for trips elsewhere. How does buying fare tickets send a message to TransLink that fares are too high? It would save me—i.e. they would forgo—$50 (which would go straight to my savings account), and make me more fit. And I would save the tickets for later if I don't use them during the month. I'm thinking of doing this in March, and maybe make a meme out of it, that is, see how many people I can get joining me.
  • Take a full weekend and get rid of stuff in my closets. Spring cleaning, hoorah!
  • Write Christmas cards to my friends. I've set a reminder in November to do this.
  • Rediscover my sense of wonder.
  • More GlobalSat GPS logger tomfoolery. Richard Akerman reminded me in a comment to a photo of mine about his article GPS on a Plane and his subsequent article GPS on a Plane II. Transferring position data from the GlobalSat DG-100 unit is still more cumbersome than it needs to, involving a trip to Windows.
  • Dance again.
  • Learn to sing, mostly to harmonize with Radiohead songs. The only karaoke song I'll sing, however, is Eurythmics "Here Comes the Rain Again". Any others and you'll have to get me even more drunk.
  • "Accidentally" break the kit lens on my camera and replace it with something decent. Also: power through my frustration with this expensive hobby of mine, photography.

That's not an exhaustive list. Lists are rarely exhaustive. What do you intend to do in 2008?

Patterson Explorer

Yesterday afternoon, needing some exercise and fresh air having spent Saturday indoors, I walked around the neighbourhood surrounding Patterson Station in Burnaby as part of the recommended walks in SkyTrain Explorer by John Atkin. Getting there by bike instead of SkyTrain was the main difference from the others I've taken, cycling down Gilmore, the Sea-to-River Bikeway leading along Patterson, it turns out, right to my destination. I locked my bike up at the station and proceeded on foot, with my GlobalSat DG-100 GPS logger in hand, taking photos with my RebelXTi. You can see the set in Flickr, as well as the map made out in Yahoo! Maps (zoom in a couple of times to see in more detail where I took the photos). I also mapped the walk out in Google Maps, since Atkin's directions were a little confusing initially.

Patterson

A couple of other notes: the switch to daylight savings time made for some mislocated photos. I'm not sure if it was the camera or the GPS unit which had the hour ahead, and luckily GPSPhotoLinker has a button to view where individual photos fit on the map, aiding in discovering this fact. God may strike me down for this, but I manually edited the GPX file that the DG-100 exports via its Windows-only utility, moving all the hours (all in GMT) back one hour. The map on Flickr is a fairly good representation of the houses in the neighbourhood appear.

Some discoveries: Patterson has two entrances, which I didn't know until visiting it. One closer to Burnaby's Central Park, and one above the bus loop. Also, I'm pretty sure that the house 5575 Jersey I photographed is not the same 5575 Jersey that Atkin mentions in his book. He says it's “a fabulous house which is almost lost from view because of the overgrowth of vegetation around it.” Either someone removed the vegetation or someone removed the house.

Needing a short break biking back home, and to make it officially an exploration worthy of the book's name, I hopped on a SkyTrain for one stop from Gilmore Station to Brentwood Town Centre Station.