Some Software To Get You Started
Sadly, a hardware connection isn't enough to make things work. You still need software. Software is what gets the two devices—your GPS and your Mac—talking to each other.
I experimented with a number of shareware and freeware GPS software products and found three that do what I need to do. Here's a quick look at each of them.
MacGPSBabel is a freeware program written by Robert Lipe and available at SourceForge.net, a programmers' cooperative. MacGPSBabel, which supports Garmin and Magellan GPSes, reads, writes, and manipulates GPS waypoints in a wide variety of formats. I think of it as my "Swiss Army Knife" for GPS/Mac communications. I use it for transferring raw data between my GPS and Macintosh or for converting GPS data from one format to another.
Launching MacGPSBabel displays its main window, which offers several basic but powerful options, as shown in Figure 2.
Figure 2 MacGPSBabel's main window, all set up to download tracks from my GPS.
From this point, follow these steps:
- Start by choosing an option from the Operating Mode menu: Waypoints, Tracks,
or Routes. Then tell the software what the input (source) data is and what the
output (destination) data is.
For example, suppose you want to download saved GPS tracks from your GPS to your Mac. Choose Tracks from the Operating Mode pop-up menu. Turn on the "Use GPS receiver for input" option. Then choose a file format from the bottom pop-up menu. (You can see all these features in Figure 2.)
- Click Download. In the Select GPS dialog box (see Figure 3), use the pop-up menus to select your GPS and specify the port to which the GPS is connected. Then click Continue.
- Use the resulting Save Output As dialog box (see
Figure 4) to enter a name
and choose a location on disk to save the file; then click Save.
Figure 3 Use this dialog box to tell MacGPSBabel about your GPS and your connection.
Figure 4 Use a standard Save dialog box to enter a name and location for the GPS data.
- Now wait while MacGPSBabel connects to the GPS and downloads the data. A spinning cursor appears in its main window while it works; you'll know it's done when a dialog box tells you so. Click OK.
Here's another example. Suppose you just downloaded a list of geocache waypoints from Geocaching.com, which uses a .loc format. To put those waypoints on your GPS, follow these steps:
- Choose Waypoints from the Operating Mode menu.
- Choose Geocaching.com .loc from the middle pop-up menu.
- Click the Select a File button and use the resulting Choose a File dialog box to locate, select, and choose the .loc file you want to import.
- Turn on the "Use GPS receiver for output" option. Click
Figure 5 You can also upload data from a file on disk to your GPS.
- The Select GPS dialog box (refer to Figure 3) appears. Choose your GPS model and connection port from the pop-up menus, and click Continue. Then wait while MacGPSBabel does its thing. Couldn't be much easier than that, huh?
These are just two examples of how you can use MacGPSBabel. The more you work with your GPS and GPS data files, the more work you'll find for this great program.
And remember one thing: Just because this software is free, it doesn't mean that the author or SourceForge.net wouldn't appreciate a donation from satisfied users. If you like this software, prove it by sending a few bucks their way. You can learn how when you download the software.
Chimoosoft's GPS Connect is a freeware program that enables you to connect to a Garmin GPS to display its real-time data on your Macintosh. You might find this feature helpful when working with a laptop. But the feature I like best is the ability to open and edit waypoint data files (on disk or downloaded from the GPS) and upload changed data to your GPS.
Launching GPS Connect displays a disclaimer telling you that the software is in beta. (I use version 0.2 with Mac OS X 10.4 Tiger.) Click the Close button to dismiss the window. Then, in the GPS Connect main window, choose the appropriate port and protocol from the pop-up menus and click Connect. GPS Connect connects to your GPS and displays some information from it, as shown in Figure 6.
Figure 6 GPS Connect's main window after connecting with a Garmin GPS.
To enable real-time tracking, choose GPS Action > Enable PVT Mode. If your GPS has a signal, it displays location data in the window. This information changes automatically as your GPS moves.
To download waypoints from your GPS, click the Download Waypoints button. In a flash, the waypoints are downloaded and appear in a window like the one in Figure 7. What's cool about this list is that you can double-click any entry in it to change its contents. You can also use menu commands to add more waypoints, upload a selected waypoint to your GPS, or save the list to disk for other uses.
I saved the best for last. Terrabrowser is a Chimoosoft shareware program that not only downloads data from your GPS, but displays it on aerial photographs or maps. All you need is an Internet connection.
The first time you launch Terrabrowser, it displays a warning. Read it and click OK. Next, you'll see a typical shareware nag screen. Wait until 10 seconds have ticked away and click Okay. (If you continue to use Terrabrowser, I think you'll find it well worth the $15 shareware fee, so pay up and enter your registration code.) Finally, you'll see a blank Terrabrowser browser window.
To set up communication between your computer and GPS, choose the correct serial port from the Serial Port submenu under the GPS menu (see Figure 8). Then, if necessary, choose the correct Garmin from the Protocol submenu under the GPS.
Figure 8 Use the Serial Port submenu to choose the correct connection.
Although Terrabrowser should support live tracking, the version I was using (1.5b3) was unable to do so with my Garmin GPSMAP 60C. That's okay, though. I use Terrabrowser for its ability to visually display GPS track logs or waypoints.
For example, suppose you have a specific waypoint saved on your GPS, and you want to see it on a satellite photo. Choose GPS > Connect to connect your GPS. Then choose GPS > Download Waypoints to download all waypoints on your GPS to Terrabrowser. They'll appear in a window like the one in Figure 9.
Figure 9 Downloaded waypoints appear in a window like this one.
Select the waypoint you want to see in a photo and click the Play button in the window's toolbar. (It looks like a blue triangle.) Switch to the browser window. If necessary, choose Photo from the pop-up menu and set the slider to choose a magnification. When the image is finished loading, it will indicate the waypoint in a photo (see Figure 10).
Figure 10 Here's my house (still under construction when this photo was taken in 1997) from a satellite. When I say I live at the edge of nowhere, I'm not kidding!
You can have a lot of fun playing with this feature. Use the slider to change magnification. Use the pop-up menu to change the type of image. Figure 11 shows another example.
Figure 11 Here's my house on a topographical map.
Of course, you can also just enter coordinates in the browser window and click the Play button to view them. Or open a GPX format file that you downloaded with MacGPSBabel or GPS Connect and display waypoints from that. Or do my favorite thing: Download and display an entire track. Figure 12 shows part of a long road trip I made this past summer (when I was supposed to be writing this article).
Figure 12 Terrabrowser can also show tracks on maps or satellite photos.