Data Hacking

Chapter 2 — Building GPS Data Cables and Power Cords
Note that not all data cables are the same. Not only won’t a cable designed for the Garmin 76
fit a GPS from the eTrex range (as you will see shortly, the connectors on the interface are different),
but a cable designed to fit a PC won’t fit, say, an iPAQ. In other words, different
devices need different cables to talk to other devices. The more GPSs you have, and the more
varied the devices you want to connect them to, the more cables you will need. Figure 2-2
shows a data cable for an iPAQ Pocket PC.
Even with the widespread popularity of USB ports on PCs, most data cables still make use of
older serial ports for data transfer. This can be a real pain on modern PCs (both desktops and
laptops), whose serial ports have typically been replaced with the more versatile USB ports. If
this is the case and you still want to make use of data cables, you will need to get a USB-to-serial
converter and plug it into your USB port to create a serial port for the job. A good-quality and
inexpensive USB-to-serial converter is available from pFranc (http://pfranc.com/cgibin/P/USB_G4).
Make sure that whatever converter you get has drivers to support the operating system you are
running on your PC.
Bear in mind that there are several different kinds of GPS connector. Figure 2-3 shows two of
the most common ones.
FIGURE 2-2: An iPAQ-to-Garmin eTrex data cable
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