Working with GPS Units

Moving Data between your GPS Unit and CalTopo

You can import and export data using a couple of methods.

1. (Most Common) Access GPS Units that support a USB Mass Storage Interface through the file interface.

   USB mass storage interface means that when you plug the GPS into your computer, it appears as a USB drive, like a thumb drive or external hard drive. All new GPS devices and most devices currently in use utilize mass storage. A list of Garmin GPS units that support a USB mass storage interface can be found here.

2. (Very Old Garmin Devices) Connect directly to a Garmin GPS using GPSIO

   GPSIO is a still-experimental replacement for the Garmin Communicator plugin, built on open web standards and using GPSBabel to read GPS data. Additional information is available here. See below for installation instructions.

Back to Top

USB Mass Storage Interface Method

These instructions assume a Garmin GPS, but similar steps will work with other GPS units that support a USB mass storage interface.

Connect the GPS to the computer with a USB cable. It may take the GPS a minute or two to save the tracks and establish a connection. Once the connection is established, the computer may chime and/or a file explorer window will open for the GPS in Windows. On a Mac, a Garmin folder will appear on the desktop.

Importing GPS Tracks and Waypoints as Lines and Markers using the USB Mass Storage Interface Method

1. On the CalTopo top menu bar, click "Import" and "Choose Files".

2. Navigate to the Garmin unit, and then the Garmin / GPX folder, select the desired track and/or markers and click "Open".

3. Un-check any waypoints or tracks you do not want to import and click "Import".

4. Track will appear in the "Lines & Polygons" folder, waypoints will appear in the "Markers" folder.

Exporting Lines, Polygons and Markers to GPS Units using the USB Mass Storage Interface Method

1. On the CalTopo top menu bar, click "Export" and "Download GPX File".

2. Un-check any objects you do not want to import and click "Export".

Depending on your browser and how it is configured, you may be prompted where to save the file or it may be automatically saved in your downloads folder.

If you are prompted where to save the file:

3. Navigate to the Garmin unit, and then the Garmin / GPX folder, change the file name as desired and click "Save".

If the file was automatically saved in your "Downloads" folder:

4. In the bottom bar of the browser (the example shown is Chrome) click the menu beside the file and choose "Show in Folder" .

5. Now drag the file to the Garmin\GPX folder on the GPS Unit.

Ejecting a GPS Connected Via USB

In Windows, eject the GPS by clicking on the USB icon in the System Tray and then selecting the Garmin unit.

In MacOS, eject the GPS by right-clicking on the GARMIN folder on the desktop and click "Eject "GARMIN".

Back to Top

GPSIO

Installing the GPSIO Extension

For the time being, GPSIO installation is a multi-step process that requires a bit of computer savvy. Hopefully, at some point in the future, this will all get boiled down to a single-click install.

Install the prerequisites if not already installed on your computer:

1. Python, which comes pre-installed on Mac and Linux installations, but may need to be installed for Windows. Click here to download the latest Python for windows. During installation, make sure to enable the option to "Add Python to environment variables" (or similar wording) so that other programs can make use of it. If needed, you can run the install program again, and modify your existing Python installation, to enable that option.

2. GPSBabel, an open source program for working with GPSs and GPS data (consider making a donation). Click here to download.

3. For Windows: the latest Garmin USB drivers, available here. For USB-mode devices (Garmin 60 or similar non-mass-storage-mode devices), you can run Windows Device Manager to verify the driver installation: if the drivers are installed properly, a plugged-in Garmin USB-mode device will show up in a category named "Garmin Devices"; if the drivers are not installed, a plugged-in Garmin USB-mode device will show up as "Unknown USB Device", causing CalTopo GPSIO transfers to abort with a red line of text indicating that no GPS was found. (Mass-storage-mode devices such as Garmin 62, 64, etc. will instead show up under 'Drives' and/or 'Portable Devices'.)

To comply with browser security restrictions, GPSIO is composed of two parts: an extension and a host. You need to install both parts.

• Install the host. Download. On windows systems you must unzip this file by right-clicking on it and choosing "Extract All"; the installer will not work properly if you navigate into the zipped folder by double-clicking on it in the windows file explorer. Either double-click on the install.py script or open up a command prompt and run "python installer.py".

• Install the extension in your browser.

  • Chrome:

    • Click the following link to install the extension

      • Restricted to CalTopo/SARTopo
    • Click "Add to Chrome"

Importing GPS Tracks and Waypoints as Lines and Markers using GPSIO

1. Connect the GPS to the computer with a USB cable. It may take the GPS a minute or two to save the tracks and establish a connection.

2. On the CalTopo top menu bar, click "Import" and "Connect via GPSIO".

3. A message will appear while the GPS is being read.

4. If the connection is unsuccessful, you may see an error message. The extension may not be correctly installed, or you may have not given the GPS long enough to connect.

5. A second message will appear once the data has been read and is being processed.

6. Un-check any waypoints or tracks you do not want to import and click "Import".

7. Track will appear in the "Lines & Polygons" folder, waypoints will appear in the "Markers" folder.

Exporting Lines, Polygons and Markers to GPS Units using GPSIO

1. Connect the GPS to the computer with a USB cable. It may take the GPS a minute or two to save the tracks and establish a connection.

2. On the CalTopo top menu bar, click "Export" and "Connect via GPSIO".

3. Un-check any objects you do not want to import and click "Export".

4. Once the export is complete, you will see this message:

5. If the connection is unsuccessful, you may see an error message. The extension may not be correctly installed, or you may have not given the GPS long enough to connect.

Back to Top