Show me a geek, and I’ll show you someone who would love to know their current latitude, longitude and altitiude to within one thousandth of a arc-second. I’m going to go out on a limb here and say that GPS tracking is a common interest amongst geeks. I’m not talking about some enterprise-level GIS system here, but rather the simple ability to query a device and find out “where am I, where do I need to go, and how long will it take me to get there?”
Until recently, GPS units tended to be an all-in-one unit like the Garmin or eTrex units, with a GPS receiver, LCD screen, and software to display position, waypoints, and maps. One could also use a wired GPS receiver connected to a laptop or palmtop, with GPS display software on the connected device. Now, with the SiRF Star II/LP GPS chipset becoming almost commoditised, and bluetooth chipsets even more so, a plethora of compact, wireless GPS receivers have come onto the market. For US$150, the Holux GR230 is a fine example of such a device.
Coupled with Symbianware’s Power Navigator 2, the GR230 turns my Nokia 6600 into a fully-fledged GPS navigation system.
The GR230’s operation is supremely simple. Entirely self-contained, you simply switch it on, then connect to it with a bluetooth capable device (cellphone, laptop, PC, whatever). Like any handheld GPS unit, the GR230 needs to see a good amount of clear sky before it will attain a ‘Fix’ after a cold start. Once this first fix is attained, I found it did a very reasonable job of retaining a fix even in all but the worst urban canyons. The main issue I found is that when a fix was lost (e.g. on entering a building) the unit had trouble re-acquiring a fix until it again had a clear sky-view (I’m guessing maybe 25% of the sky needed to be visible). I understand this is normal for compact GPS units. On the upside, the GR230 was extremely fast to obtain a cold-start fix (~30 seconds) from the dashboard of my car in normal suburban conditions. It also has a connector for an external antenna, which might help if reception is a problem in certain areas.
The unit’s ‘user interface’ consists of three LEDs:
- GPS Status: orange; blinks when GPS Fix is valid, solid if not.
- Bluetooth: blue; rapid blinking when searching for a device, slow blinking when transmitting data.
- Battery: two-state; orange when battery low, green when charging, off when charge complete.
The only slightly awkward thing about the GR230 is that it has a hard-coded bluetooth pairing password. I suppose this provides slightly more security than some similar devices that have no pairing code, or 0000. It caused me a tiny bit of consternation when the GR230 attempted to pair with my PC, and I was asked for a pairing code. This was the only time I had to defer to the manual to discover that the code is hardcoded to “6268”.
Once connected, the GR230 simply starts spewing NMEA-formatted data down the serial connection. As a software developer, I was interested enough to whip up a small application to read and decode the NMEA data, and display my current position, heading, and speed on the 6600. I was planning to go further and attempt to render my position on a moving map, but then I discovered Power Navigator 2 (PN2).
PN2 does pretty much everything you would want from GPS display software. It does basic things like displaying location, heading, speed, and altitude in a simple, clear layout that makes for easy reading even on the 6600’s small screen. For more advanced users, PN2 will happily take manually entered waypoints, routes and bearings. PN2 will also display your track as a moving line, and this track information can be overlayed in realtime on a map image. Map images can be imported into a freeware Windows application, which can be used to ‘calibrate’ the image by entering coordinates of a number of known points. This means that any source can be used for map data (e.g. scanned maps, downloaded aerial photos), but beware that some maps and photos are not ‘rectified’, meaning that positions will never line up exactly.
Overall, Power Navigator 2 is very simple and intuitive to use. The separate views are mapped to numeric keys, so switching between views is very quick. Other keys do what you would expect (e.g. joystick scrolls the map around), and all options are nicely grouped under the menus.
The full range of views available from Power Navigator are:
- Track View: displays current position and historical track, optionally overlayed on a map image and/or grid. Can also display overlayed lat/lon, speed and altitude.
- Compass View: displays a fixed or rotating compass, overlayed with positional and speed information. If a waypoint is active, this view can display bearing and distance to waypoint.
- GPS Info View: displays satellite information, including how many satellites are ‘visible’, the relative signal strength of each, and the polar location of the satellites. Also displays ‘Fix’ status (none, 2D or 3D).
- Information View: extra track information, including a speed or altitude over time graph
- Settings View: lets you change all the PN2 settings, including display units, waypoint/route editing, map configuration etc.
For geocaching fanatics, PN2 can import and export waypoints in GPX format. Geocache locations can be downloaded in GPX format from www.geocaching.com. Through my local GPS user group, I was also able to find GPX files of local Points of Interest. This includes such things as hills, beaches, scenic spots, etc..
In summary, if you have a Series 60 phone, the Holux GR230/Power Navigator configuration is an extremely efficient way of getting a full GPS navigation solution.