The GPS-enabled BlackBerry 7520 and 7100i used to be the only Research In Motion (RIM) devices that could be used with location-based services.  With the advent of Bluetooth GPS peripherals (like the GPS 10 from Garmin) along with the Bluetooth chips in other recent BlackBerrys, you can now leverage global positioning with most any RIM handheld nowadays. One of the most entertaining and widespread applications of GPS devices in general is an activity called Geocaching.  Geocaching involves enthusiasts from around the world hiding small, waterproof containers called "caches", recording the exact coordinates using a GPS device, and then uploading some general information to the Geocaching Web site so others can try to find it. 

If you've never tried it, do a search on the Web site for caches hidden near your address—you'll be shocked at the number of caches within a short distance of wherever you happen to be.  It's all free and it's good, clean fun for the whole family.

A nifty application called Spot for BlackBerry turns your BlackBerry 7520, 7100i, or any Bluetooth-enabled BlackBerry device connected to a GPS receiver into a full-fledged Geocaching machine.  Spot is available for $49 from a company named Skylab Mobilesystems. 

There's an over the air (OTA) install for the program, so just point your BlackBerry Browser to this URL to download and load Spot onto your handheld. Different versions of Spot exist for whether you're using a device with a built-in GPS chip or any other BlackBerry with Bluetooth enabled - so be sure you select the proper download.

Once you install Spot for BlackBerry, look for the icon that looks like it's been shot with a green paintball.



Main BlackBerry Screen

When you start Spot, the software confirms its connection type to the GPS and then takes you to the main menu.  To verify that you're actually getting a reading from the GPS chip, go to the Position Info item on the menu and look for your current coordinates.  These will update every few seconds as it periodically polls the GPS chip.  If you're not getting a proper reading, the coordinate fields will be blank


Position Info Screen

Pick Your Cache & Enter the Coordinates
Once you've identified the Geocache that you'll be hunting for, you need to enter the coordinates into Spot as a waypoint.  There are two ways to accomplish this.  The first way is to simply enter the coordinates by hand (well, by thumb) by going to Waypoints from the main Spot menu and selecting Add Waypoint. 

Spot wants these coordinates in degree decimal format, which is not the default format on the Geocaching Web site.  However, on each cache's page there is a convenient link that will convert the coordinates to a variety of formats, one of which is labeled "DegDec" - that is the format you want.

You can also choose a slightly more difficult, but less error prone route.  The cache's page will have a link to a .LOC file which contains the coordinates and brief description of the cache in a standard format that Spot supports.  Unfortunately, the Geocaching site requires that you log in to retrieve this file, so Spot can't download the file directly from geocaching.com.  You can, however, download the file yourself and make it available on another Web site that you have access to. 

I downloaded the .LOC file for a cache that I planted and uploaded it to my blog so I could test the import feature in Spot.  Under the Waypoints section in Spot, choose the LOC Import (web) menu item and enter the URL for the .LOC file.  Spot retrieves the coordinates automatically and creates a new waypoint for you.  Although this is a little more work, it prevents the possibility of you entering the wrong coordinates - a mistake that can ruin an afternoon (I speak from experience on this one).

 
Download Screen

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Geocaching Cache

It's important that you name your new waypoint with name that is suggested on the Geocaching Web site.  This will allow you to use one of Spot's excellent Geocaching integration features: automatically downloading the description of the cache as it appears on the web site.  To do this, go to Manage Waypoints and then select the waypoint you just created. 

Click the trackwheel and select Details.  On the next screen, click to select Get cache description to retrieve the description.  The only issue I had with this is that the entire description is downloaded - raw HTML tags and all.  Perhaps in a newer version the HTML tags could be removed.


Getting Cache Description

The Hunt Begins
To put Spot in the navigation mode that you might be familiar with if you've used other GPS devices, go to the Manage Waypoints section and select the waypoint that corresponds to the cache.  Use the trackwheel and select Route To from the menu.  This immediately puts you in navigation mode and points you in the direction of the target coordinates.


Navigation Mode

Just like the navigation mode in any GPS device, it assumes you are holding the device directly in front of you and that you are walking straight ahead (it doesn't function as a compass, where if you spin around the arrow always points north).  If you're new to GPS devices, this can take some getting used to.  This is because the device doesn't know which direction you're facing, it only knows which direction you're heading by polling the GPS every second or two.  This is worth reviewing with anyone that's along for the ride.

Smart Feature to Conserve Battery
If you've used GPS software on your BlackBerry before, you'll quickly notice the drain it has on the battery.  In fact, these devices sometimes don't carry a charge past the psychological breaking point of 24 hours under normal use.  In navigation mode on my Garmin GPS, it polls the GPS chip every second no matter how far away you are from your destination, for example. 

The makers of Spot recognize the battery life issue on the BlackBerry and use some intelligence in the way it polls the GPS for its current location.  When you're relatively far away from the cache in navigation mode, Spot polls less frequently.  Spot will poll the GPS chip more often as you get closer to the ultimate destination, where the frequency of the updates becomes important.  In fact at far distances, I thought that the software might not be working at all since I was used to the frequent updates of my Garmin.  This took a little trial and error to figure out what Spot was doing.

Other Features
In addition to Geocaching, you can use Spot for BlackBerry to do other things that standard GPS devices can do. 

For example, it can plot your location on a map in real time.  Spot can also keep a track of where you've been overlayed on a map.  The maps are downloaded using the data connection on the fly.  This is an important advantage over standard GPS devices that have a limited amount of memory and a very undetailed map by default. 

If you want more detailed maps  with a regular GPS, you have to buy them and load them on your device.  Even then, you have to pick and choose which areas you'd like to have a detailed map.  With the always on data connection of a BlackBerry, very detailed maps can be downloaded on demand without excessive memory requirements on the device.

Conclusion
If you like to Geocache or if it sounds interesting to you, I'd consider this an excellent addition to your BlackBerry.  The convenience of the GPS-enabled BlackBerry devices is fantastic and I'm looking forward to seeing other ways that software developers can use the device to do creative things.

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About the Author
Dave Mabe, the author of the O'Reilly book BlackBerry Hacks, is a largely self-taught engineer and writer who strives to create a simple, elegant solution to a complex problem. He has worked in the communications industry for eight years and has worked with BlackBerry devices for almost five.