How to use a Garmin GPS with your Mac

Introduction

Are you a Macintosh and Garmin GPS user?

With the right software you can transfer waypoints and tracks, work with your data, and even run MapSource to transfer maps.

In this article I’ll show you how to:

• Connect your Mac and GPS
• Transfer waypoints, tracks, and routes
• Get MapSource running on your Mac
• View your data and plan your next trip
• Share your trip data and maps

Let’s get started!

Getting Connected

The first step is getting your GPS connected. If you have a newer Garmin GPS that supports USB, you’re all set. Just plug your GPS and Mac together. There are no drivers to install.

Older GPS receivers that have serial ports will need a USB to serial adapter and its associated drivers. KeySpan makes an adapter that will work. It allows you to plug your Garmin serial cable into your Mac USB port.

Transferring Waypoints, Tracks, and Routes

Now that your GPS and Mac are connected, we can transfer data from the GPS and view it in Google Earth. We’ll use a free program called GPSBabel to transfer the data.

When you visit the GPSBabel site, go to the downloads section and download the .dmg file for Mac OSX. There is no installer, and you cannot simply drag the application to your Applications folder. What I did was create a folder called GPSBabel and put the contents of the disk image there. I then put the entire folder into my Applications folder.

Transferring from your GPS

To transfer data to and from your GPS, make sure it’s connected to your Mac and start GPSBabel.

You should select the following options:

• Operating Mode: Select Waypoints, Tracks, Routes as desired
• Input Options: Select Use GPS Receiver, and select the port. In my case I selected USB.
• Output Options: Select Use File, and for Type I selected Google Earth because that’s where I want to use my data.
• Filters: You don’t need to select anything

Once you have your options selected, click Save File at the bottom. Your data will be transferred from your GPS into the file you specified. In this example I saved the data as a file for Google Earth.

If you don’t have Google Earth, go download it now. It’s fun to use even without a GPS.

To load your data into Google Earth, select File, Open, and find the file you created using GPSBabel. Google Earth will load and display all of your waypoints and tracks. They will be listed in your My Places section on the left. There you can enable or disable the parts you’re interested in. In my case, I disabled the track points to reduce clutter.

If you upgrade to the $20 Google Earth Plus you’ll be able to import data directly into Google Earth and skip the GPSBabel step. However, you’ll still need to use GPSBabel to transfer data to your GPS.

Transferring to your GPS

You’ll need some data to transfer, and Google Earth is a good tool for creating that data. Google Earth will let you create tracks and waypoints, then save the data so GPSBabel can transfer it to your GPS.

It’s a good idea to organize your data using folders in the My Places section of Google Earth. When you have data in folders, you can save just that folder instead of everything in Google Earth.

In this screenshot I’ve made a folder and created some waypoints.

To save the data just right click (or control + click if you don’t have a Mighty Mouse) on your folder and select Save As. It doesn’t matter which file type you choose. GPSBabel will figure it out.

Once your data is saved, go back to GPSBabel and set it up like this:

• Operating Mode: Select Waypoints, Tracks, Routes as desired
• Input Options: Select Use File, then click the Select button and find the file you saved from Google Earth
• Output Options: Select Use GPS Receiver and select the proper port
• Filters: You don’t need to select anything

Make sure your GPS is connected and click Send GPS at the bottom. The data should now appear on your GPS. You’ll notice that Google Earth doesn’t let you pick the nice Garmin waypoint icons, so the icons will be generic.

Upload Maps to your GPS

Uploading maps to your GPS receiver requires MapSource, which is only available under Windows. In 2005 Garmin announced they would be the first GPS manufacturer to support OSX Tiger. They have yet to release anything.

Update! A Garmin representative posted a comment on this article indicating that they are making real progress on OSX applications. View the comments for details.

If you have a G4 or G5 Mac you can try running MapSource under Virtual PC. I found some older instructions that might help if you want to try. It’s the only way if you don’t have an Intel based Mac.

Running MapSource on Intel Macs is pretty easy, and works flawlessly. There are two ways to do it:

• Install BootCamp and dual-boot between OSX and Windows XP.
• Buy Parallels Desktop and run Windows XP within OSX.

Dual booting is inconvenient because you have to reboot every time you want to run MapSource, but it will run at the fastest possible speed.

Running MapSource using Parallels Desktop works really well, and is what I recommend. The software is $79 and has a free trial.

After you follow the Parallels documentation and have Windows XP running, you can install MapSource just like you would on any PC.

The only extra step you need to do is tell Windows that you’ve connected your GPS. Once you have it plugged in via USB (or through the serial to USB adapter, which will require drivers under Windows), click the USB icon on the lower right of the Parallels window and tell it to connect your GPS.

Mine shows up as a device called “vendor specific.” Once connected, you can use MapSource just as you would on a real PC.

When you install MapSource, be sure to visit Garmin and download the latest updates.

Do you really need to buy software or dual boot?

Transferring maps isn’t something I do all the time. My 60Cx can hold my entire state’s City Navigator and Topo maps at the same time, so I don’t have to use MapSource at all unless I’m travelling out of state. If you’re like me, it may not even make sense to get MapSource running on your Mac. You could just use someone else’s PC as needed.

Of course, if you live in a state that has actual cities and topography, unlike Iowa, you might transfer maps more often.

Working with your data

Now that you have everything setup, you can get on to the fun stuff.

Viewing Data

When I go hiking I like to take the GPS and leave it on the entire time, gathering track data. I also mark interesting points along the way. To save battery life, I put the GPS in battery saving mode. That will reduce the track resolution, but when walking it doesn’t really matter.

Back at home I use Google Earth Plus (or GPSBabel, then import into the free Google Earth) to download my data into Google Earth and view it in 3D. If you’re somewhere flat, like Iowa, you can go into the Google Earth preferences and increase the terrain exaggeration. If I didn’t do that, the giant hill I climbed wouldn’t even show up. I’m not sure that I could climb an actual giant hill.

I also use Google Earth to clean up my waypoint names and tracks.

Trip Planning

Google Earth also makes an excellent planning tool. Before going on a trip I draw the route I want to take, and mark points of interest along the way. To get the data to my GPS I save the data as KML, then use GPSBabel to transfer it.

Sometimes I’m visiting a place that doesn’t show up in Google Earth very well. For example, a small state park that has trails and campgrounds. If you can find a more detailed map, you can overlay the map into Google Earth. It’s tricky, but you can make the map semi-transparent, then resize and move the map until it lines up with landmarks that appear on both the map and in Google Earth. Once you have the map aligned you can draw tracks over any tails, and make waypoints for the camp sites. You can then upload the data to your GPS.

In this example I found a map of this state park on the park’s web site. To overlay the image, scroll to the approximate location then go to the Add menu and select Image Overlay. A window will appear the lets you name the overlay, select the image, make it transparent, and many other options. After you select the image you’ll see green lines that you can click and drag to resize it.

Sharing your Data

It’s fun to share your GPS data to show others where you’ve been. If you know someone that has Google Earth you can just send them a saved Google Earth file, which they can view in Google Earth or transfer to their GPS using GPSBabel. If you want to share data with a MapSource user, just use GPSBabel to convert a Google Earth file into MapSource format.

Sharing on the Web

An easy way to share your data with everyone is to put it on a web site. I’ve created a free site just for that purpose, called DiscoverMachine. It lets you upload your GPS data and display it on Google Maps, and even has USGS topo maps and aerial photos.

To show your GPS data on DiscoverMachine, follow these steps:

• Use GPSBabel or Google Earth to save your GPS data as either a GPX XML or Google Earth KML file.
• Create a free DiscoverMachine account.
• Create a new map, then scroll to about where your GPS data will be.
• Click “Set this as the starting map location” below your map.
• Click “Upload GPS Data” below your map.
• Find your file and upload it.
• Your data is now on the map! You can bookmark the map and share it with anyone that has a web browser.

Conclusion

As you’ve see, with the right software your Mac can be a very handy tool for use with GPS receivers. Someday Garmin will release a version of MapSource for OSX, but until then you can do almost everything without it, and it’s still possible to run it if necessary.