9/14/2001
Bought a Magellan 310. Works fine, seems to lock onto the satellites well, but the display isn't too great and the buttons definitely need more debouncing.
9/15/2001 eve.
Bought the basic Garmin Etrex. Seems harder to work with one hand, and the UI is somewhat clunky, but then again it's more complex. Shows a trip route, which is not a must for me, but neat. Could have used it earlier today when driving around.
Entering new waypoints could be easier. I guess one can upload them from a computer. Will try to use the old G3 for that.
I'm now almost certain I'll get the Magellan 315. Higher resolution display, and - judging by the 310 - probably more reasonable GUI that the Garmin. Considered Garmin 12 also, but it doesn't seem to do more that the 315, is older, and some of the menus seem overly complex. I don't want to have to read the manual while using it...
Plus the Magellan antenna seems to be better; the Etrex couldn't get a fix on the first floor of the house, while the 310 had no such problem. Garmin announced a new model 72 with a better antenna, but it has buttons above the screen (which looks inconvenient) and I don't want to wait until November.
9/16/2001
Returned the 310 and the Etrex, bought the 315. A bit more money, but better screen than either of those, easy to use, does all I need but not too much more. More intelligently designed, I think, than the other two. So far I'm very happy with it.
Went to www.mapquest.com, entered the coordinates from recent trips, zoomed the map, and BOOM -- that's _exactly_ where I was at the time... quite eerie. As I understand, SA was turned off on May 2, 2000. The 315's averaging function usually indicates an error of at most 25 feet or so (sometimes as little as 6 feet). This thing is even more accurate than I expected.
Switching from DD MM' SS" to DD.DDDDD format so as to get maximium precision and compatibility with many sites. The last decimal won't matter given the accuracy of the receiver, but it's useful for comparing multiple readouts.
To get a MapQuest map, use the URL: http://www.mapquest.com/maps/map.adp?latlongtype=decimal&latitude=41%2e97617&longitude=%2d88%2e72575
Even better, Google maps: NIU Watson Hall, using the URL
href=http://maps.google.com/maps?q=41.93383,+-88.76988+(NIU+Watson+Hall)&iwloc=A&hl=en&zoom=2
To get a Terraserver image: http://terraserver-usa.com/image.aspx?Lon=-88.72575&Lat=41.97617&w=1&ref=G|-88.72575,41.97617
Another source of maps (added 5/16/2003): http://www.acme.com/mapper/
9/19/2001
Rigged a simple connector for the 315. Tried my older G3 with GPSy (works fine, but a bit rough and limited as a demo), then with a DB-9 connector for the SunBlade's serial port. Used gpsutil from freshmeat.net (only had to change the serial device to /dev/term/a). OK for very basic up/downloading.
Apparently the 315 won't do any serial communication if it isn't tracking. But it talks when set to "simulate"; the speed etc. is of course bogus then, but waypoint up/downloads work.
9/20/2001
Fiddling with software; GPSy on the Mac OK but it didn't exactly awe me, esp. for a demo of a commercial product. MacGPS doesn't do Magellan.
Compiled gpsutil by Brian Henning, and it miraculously works on a SunBlade 100 (only had to change the port to /dev/term/a). It's very limited, but I might tweak it myself.
gpsman (Tcl/Tk) looks fairly promising, but despite a note about Magellan support found in the changelog, the newest version I could find only lists Lorance and Garmin. And it's hard to figure out what exactly it's doing and when. Seems to receive NMEA from the 315 but displays them only after an arcane sequence of button presses and menu selections is made.
Tried writing some rules for parsing the various lat/long formats floating about, and it's hopeless. I guess I'll stick to decimal (most unambiguous and accurate) or DDMM.MMM{N|S} DDDMM.MMM{W|E} (this is what the Magellan seems to send as waypoint data, and it's also the format used by http://www.waypoint.org/).
9/21/2001 eve.
Got the Magellan protocol specs; it still doesn't tell me how to get the serial data output coordinates with more precision than ddmm.mmm (although it should be possible, internally the values are stored with more digits), and how to get/set waypoint creation dates.
For now I'll use DD.DDDDD for all data, with a PHP translation to DDMM.MMM for those who want it.
9/22/2001 eve.
Still very happy with the 315 after a few longish trips. All menus logical and easy to use, buttons on top work well for me, good display (although I'd like more customization on some screens and slightly stronger backlight).
Used Rayovac NIMH rechargeable for a few days; other than showing lower voltage (as it should) the 315 worked fine for about 10 hours with them.
7/5/2005
The GPS 315 finally died. A few months ago it developed a few blank vertical lines on the LCD. They were getting worse, so I decided to cut the case open. In case anyone wants to see the inside, here goes.
The delicate flat connector was apparently getting unstuck right next to the top edge of the LCD, and nothing I tried helped - quite the opposite, it was getting even worse. I could try and find a cheap broken 315 or 320 and hope the screen works (it's easy to replace), but that might be a waste of time. Plus it would be nice to have a newer GPSR with WAAS.
The Explorist series seems to be a real step backwards. Sportraks are getting hard to find. Everything else is either of suspect reputation (Cobra?) or way too expensive. I'm looking at several Sportrak Map units on eBay now.
7/11/2005
Got the Garmin GPS V on eBay. So far I'm extremely happy with it. Very nice hi-res screen, the basemap is probably all I need (it came with all the accessories but no software), the design is great. It has no problem getting WAAS correction for all satellites and shows high accuracy most of the time (6-8 ft). The cigarette lighter cord means I can keep it turned on all the time. All this for less, in 2005, than I paid for the 315 in 2001...
Check out: gpsdrive and Milbert's GPS software page (hmm, not much there). Also pyGPS and gpsd. A Mac OSX package but it supports Garmin only? Also see Magellan Waypoint Manager for OS X, which isn't quite there yet, but looks promising. A beta of Mac SimpleGPS looks nice, but mangles waypoint data from my GPS V. A Japanese program GPSe and a companion package MAPe. There is also a Mac GUI version of the powerful GPSBabel. A comprehensive list of Mac GIS packages by Stephane Gueritte.
Interesting uses:
Finding the car at a big parking lot.
Tracing where your cat goes at night.
