The Deliverator – Wannabee

So open minded, my thoughts fell out…

My GPS Adventure

Posted by Deliverator on June 7th, 2007

My Holux GR-213 GPS “mouse” and Evermore DL-200BT Bluetooth Gps & Data Logger arrived today and after wrapping up the day with an un-fun data recovery project (thankfully someone else’s for $ and not my own) I gleefully got down to the ritual unboxing and ignoring of manuals.

I slapped the Holux on the trunk of my car (it has an integral magnet to hold it in place) and plugged it into a USB extension cable and thus into my carputer. I fired up the carputer and it was instantly recognized and assigned a serial/com port. There is an included driver cd, but I didn’t need to use it, probably because the carputer already had the necessary usb->serial driver installed from the previous Holux GPS. I did a milk run down to Factoria as an excuse to test the new Holux out. It got a fix impressively quickly and maintained a connection with at least 7 satellites at all times, except for one brief drop to 5 while driving under the super wide I-90 overpass. This impressed me greatly as the previous Holux GPS rarely maintained more than 4-5 on the my hill, likely due to the large number of very tall trees. I guess all the good things I have been hearing about the SiRF III chipset are true.

The DL-200BT I tested later in the evening after giving its lithium ion battery a few hours to charge from my computer’s USB port (with the included USB->power adapter). In addition to the unit itself and battery, it came with a non-slip mat for mounting on a car dashboard, car charger and a CD with tools and drivers on it. Sadly missing from the box was a USB data cable to plug into the unit’s proprietary ps2 like USB connector. As I hate pointless proprietary connectors (and companies looking to “Nickle and Dime” their customers by selling overpriced cables), I might do some soldering work and add a standard USB mini port at some time. I will post the pin out when I get around to it.

I painlessly paired the unit with my computer at home and played around with the included software for a few minutes just to make sure it was working. I picked up the DL-200BT and my Nokia N800, put on my coat and went for a walk. As I walked out the door, I downloaded a few podcasts onto my N800 using gPodder to listen to while I walked. I then went into the control panel and paired the DL-200BT with my N800. I then fired up Maemo Mapper, went into the settings menu and had it scan for my GPS. It added the GPS’s MAC immediately and within a couple minutes Maemo Mapper auto centered onto my position. I’d downloaded fairly detailed maps of Washington onto a SD card a while back, but just for fun I decided to fire up the EDGE connection on my phone and let Maemo Mapper download maps on the fly. The connection was fast enough to keep up with my walking pace, but I am unsure whether this connection speed would be adequate for on the fly downloading of maps at highway speeds. Maemo Mapper has a nice built in display showing the number of locked satellites and signal strength of each. I kept glancing at it while walking around the hill. Unfortunately, the GPS used in the DL-200BT is nowhere near as good as the one in the Holux. Over most of the hill, the GPS ping-ponged between 2 and 3 solid locks and fairly often lost lock entirely. Only rarely did it have four satellites locked, which is necessary for vertical positioning. I also noticed several occasions when the map showed me walking through the middle of someone’s back yard when I was walking in the middle of the street or showing me on the wrong side of the street. Both of my Holux GPS units have exhibited far better positional accuracy and higher number of locked satellites than this Evermore unit. If you need a robust GPS data logger for some fairly critical application, I would suggest looking elsewhere.

When I got home, I launched the included data logger application and easily exported my logged routes and exported it to Google Earth with the click of a button. The data logger application is easy to work with and can export to a wide variety of common data formats including OziExplorer, .gps, Waypoint+, NMEA0183, GPS Exchange and the KML format used by the various Google mapping apps. For visualization with Google Earth, there is a single button export option which will launch Google Earth and zoom to show your route. The software is definitely this unit’s strong suit.

Here is a screencap of my route from within Maemo Mapper and a cropped screenshot from Google Earth. I purposefully started my logging from several blocks from my home to avoid all you crazy internet stalkers :)

Maemo Mapper

Google Earth GPS Log