Troubleshooting GPS Receiver Connection Problems

If you follow the instructions that come with the your software to connect your GPS receiver to a computer, usually getting the two devices talking is painless.
If you do run into problems, follow this set of steps, in this order, to help you identify a possible culprit for your connection troubles:

1. Always make sure the cable is securely plugged in to both the GPS receiver and the computer. While you’re at it, check that the GPS receiver is turned on.
2. Make sure that the baud rate and the protocol are the same in both the GPS receiver and the interface program. Double-check this again if you can’t establish a connection. Even if the baud rates match, they may be set too high — thus causing communication errors. When in doubt, lower the baud rate. You can either step-down a rate at a time or go directly to 4,800 or 9,600 baud. Although this is slow, this rate shouldn’t generate errors.
3. In the interface program, make sure that the correct COM port is specified. If you can’t get a connection, try different COM port numbers until you find one that works.
4. Always check the program’s user manual, online help, or support section of the vendor’s Web site for specific information on interfacing with a GPS receiver.

If you can’t get your GPS receiver to talk to your computer and you happen to have a PDA, turn off the PDA synchronization program first. PDA synchronization software that’s running in the background is a frequent culprit in causing GPS receiver interface problems.

G7ToWin and other utilities

G7ToWin is the Swiss Army knife of the GPS world. This free utility program works with most all brands of popular GPS receivers. With this Windows program, you can

• Upload waypoints, routes, and tracks to your GPS receiver.
• Download waypoints, routes, and tracks to your computer.
• Edit waypoint, route, and track data in a spreadsheet-style window.
• Create waypoints, routes, and tracks.
• Save waypoints, routes, and tracks in different file types. (Remember that GPS receiver and software manufacturers all use a number of different file formats for waypoints, routes, and tracks.)
• Save the image that appears onscreen of many Garmin GPS receivers.

G7ToWin is a must for the serious GPS receiver user. Its author, Ron Henderson, continues to add new features to the program. DOS and Pocket PC versions of the utility are also available. You can download G7ToWin at www.gpsinformation.org/ronh.
Other GPS utilities worth consideration include

• EasyGPS: A popular, free utility for creating, editing, and transferring waypoints and routes, available at www.easygps.com.
• GPS Utility: A popular freeware/shareware program that lets you manipulate and map waypoints, routes, and tracks and works with Geographic Information System (GIS) data. It’s available at: www.gpsu.co.uk.
• GPS TrackMaker: A free utility that creates, edits, and deletes waypoints, routes, and tracks. It supports mapping features. You can download the program at www. gpstm.com.
• GPSy: For users who want to interface their receiver with a Mac. For more information, see www.gpsy.com.

How to Transfer Data from GPS Receiver?

GPS receiver interface programs tend to work the same way, although they have different menus, dialog boxes, commands, and appearances. When you transfer data between your GPS receiver and PC, you’ll either be

• Capturing current location coordinates to use with a real-time mapping program you have running on your laptop (or PDA). As you move, your location appears on the map.
• Downloading or uploading waypoints, routes, tracks, or map data.

The process to complete both of these tasks is the same. (If you have a GPS receiver with a memory card, you don’t need a cable to download or upload waypoints, routes, tracks, or map data because you’ll be using the memory card and a card reader to do this. However, you’ll still need a cable to capture your current location to use with a real-time mapping program.) Take a look at the general steps involved in transferring data with a cable:

1. Connect the PC interface cable to your computer and to your GPS receiver.
2. Turn on your GPS receiver. The GPS receiver doesn’t need to have a satellite fix to transfer data unless you’re using the receiver with a mapping program that’s plotting your current location.
3. Run the interface program.
4. Ensure that the protocols and settings on both the GPS receiver and the computer are the same.

At this point you can

• Select the type of data (waypoints, routes, or tracks) and upload it to the GPS receiver from your computer or download it from the GPS receiver to your computer.
• Upload a map to the GPS receiver that was created with a GPS manufacturer’s mapping program.
• Have the GPS receiver start providing location data to the interface program for real-time mapping.

Check the program’s user manual or online help for specific instructions on transferring data between your GPS receiver and a PC. If you’re transferring data to and from a memory card, refer to the GPS receiver’s user manual or support Web site. With some receivers, you can simply drag data between the memory card and the hard drive via Windows Explorer. In other cases, you might need to use a utility program, such as G7ToWin or EasyGPS.

Transferring GPS Data

After you have a cable and then get the ports, baud rates, and protocols all figured out (or have a memory card and card reader), the next step is getting the data transferred between the GPS receiver and your computer. This is where software comes in, and you generally have three options:

• GPS manufacturer software: The commercial mapping programs that GPS receiver manufacturers sell can all upload and download waypoints, routes, and tracks as well as upload maps to certain models of their GPS receivers. GPS receivers that display maps work only with proprietary maps provided by the manufacturer. You can’t upload maps from third-party mapping programs into your receiver. Sometimes GPS novices believe that they can load maps from DeLorme, Maptech, National Geographic, or other mapping companies directly into their GPS receiver. You can’t.
• Third-party mapping software: Most third-party, commercial map programs can also upload and download waypoints, routes, and tracks —they just can’t upload a digital map that appears on your PC. This is an essential feature so you can overlay GPS data on a digital map to see where you’ve been or plan a trip with the mapping software and then upload waypoints and routes from your computer to a GPS receiver.
• GPS utilities: Software programs used to interface GPS receivers to computers are utility programs designed specifically to download and upload waypoints, routes, tracks, and other information. These programs are usually freeware or shareware and have a number of useful features.

A few drawbacks to GPS receivers that support memory cards

Here are a few drawbacks to GPS receivers that support memory cards:

• Added cost: They add a bit more cost to the receiver price because of the built-in card reader and associated technology.
• Reader: You need a memory card reader connected to your computer to transfer data back and forth between the GPS receiver. However, some computers (notably laptops) have built-in card readers. If your GPS receiver didn’t come with a card reader, any third-party reader will work. These devices are inexpensive and easy to use. Just plug the reader into a USB port, and Windows treats the memory card like a hard drive or floppy disk. You can then copy data back and forth between your hard drive and the memory card. Card readers are inexpensive, and you can purchase a basic model for under $20.
• Removal: Memory cards can be a little tedious to swap because you need to remove the GPS receiver batteries to access the card slot. Just like digitals cameras, GPS receivers that support memory cards usually come with a card that has a relatively small amount of storage space (8–16MB). In fact, if they both use the same type of memory card, you can swap a card between your digital camera and GPS receiver. You’ll probably want to upgrade to a larger capacity card. Blank memory cards with the GPS receiver manufacturer’s brand name tend to be more expensive than standard MMC and SD cards. I don’t find any difference between the two, and you can save money with third-party memory cards in your GPS receiver.

Managing GPS Receiver Memory

If you own a GPS receiver that uses a memory card, congratulations! I personally like the versatility these receivers offer (such as stuffing a bunch of maps onto a single, large-capacity memory card). This section talks about how to get the most out of your memory card GPS receiver. If your GPS receiver uses only a cable to connect to a computer, you can skip this section. Better yet, read along to see how memory cards work for transferring data.
If your GPS receiver supports using a memory card, you have some significant advantages when exchanging data with a computer, including

• Upload speed: Uploading maps from your computer to a GPS receiver is considerably faster with a memory card than via a serial port cable. Because GPS receivers communicate at a fairly low baud rate, transferring 10–20MB of map data can take a long time (up to hours depending on how the serial port is configured).
• Affordable and practical: Memory cards have gotten inexpensive over the years. You can load frequently used maps on several cards and not bother with repeatedly uploading data from map program CDs. You can easily pick up a 128MB memory card, which I’d recommend as a minimum size, for under $40. I like to use Froogle (http://froogle.google.com) to find the best prices online.
• More storage: Memory cards give you considerably more storage than GPS receivers with fixed amounts of internal memory. You can currently purchase memory cards that provide between 8–512MB of data storage. Handheld GPS receivers that don’t support memory cards might have only 1–115MB of internal storage.
• Versatility: You can use the memory card in your PDA, digital camera, and cellphone (if all the devices support the same type of card).
• Minimal settings: When using a memory card, you don’t need to worry about COM ports, baud rates, and protocols when transferring data. (However, if you’re using your GPS receiver with a laptop and cable connected to a moving map program, you still have to contend with getting all the settings just right.)

GPS Receivers Protocols

A protocol is a way for two devices to successfully talk with each other. Think of a protocol as a language with a strict set of rules. When one device sends a message to another device, it expects a certain type of response back. This structured, back-and-forth conversation takes place until one device sends a message that says the conversation is over.
Likewise, when you connect a GPS receiver to a computer, a certain protocol is used to transfer data back and forth between the two devices. You need to ensure that the same protocol has been selected for both devices. If two different protocols are used, it’s like the GPS receiver speaking Russian to a computer that understands only Chinese.
The protocols typically used with GPS receivers are

• NMEA: The National Marine Electronics Association came up with the NMEA 0183 standard, which is a protocol for transferring data between marine-related electronics such as GPS receivers, autopilots, and chart plotters. Virtually all GPS receivers support the NMEA 0183 standard, which uses widely documented text messages. Typical NMEA data includes latitude, longitude, time, and satellite status. NMEA comes in several different versions, including 1.5, 2.1, and 2.3. Make sure that this version number matches both the GPS receiver and the computer program that you’re using.
• Proprietary: Some GPS manufacturers have their own proprietary protocols for communicating with a GPS receiver. These protocols send additional data that isn’t included in the NMEA standard: for example, altitude, speed, and position error.

NMEA is the de facto standard for getting a GPS receiver to talk to a computer. However, some programs support GPS manufacturer proprietary protocols. If you have a choice between NMEA and a proprietary protocol (for example, the Garmin protocol used with Garmin GPS receivers), select the proprietary protocol because it can supply richer data to a program.