Data Hacking

Chapter 2 — Building GPS Data Cables and Power Cords
FIGURE 2-25: You need to undo these screws.
4. The bit inside that you are interested in is the little circuit board that plugs directly into
the iPAQ serial port when it rests in the cradle. This is the green board with the black
socket and USB cable connected to it.
5. Carefully free the board from the slot in the cradle so you can work on it (see Figure 2-26).
Be very careful when you are handling it because the USB cable wires can easily break
off of the board. If they do break, it’s not the end of the world — you can easily solder
the connections if it happens; but as always, it’s better to avoid it.
6. You now need a cable with a GPS connector on one end. On this, three wires are of
interest to you — from pin 2, pin 3, and pin 4. The goal is to solder these three wires
to the appropriate pin on the cradle. At first, there may seem to be a lot of pins, but
you will be relieved to know that only twelve are used, the rest being frame grounds.
7. The two pins that are of interest to us are pins 7 and 8, as shown in Figure 2-27. Pin 7 in
the cradle needs to be connected to the wire from pin 2 on the Garmin eTrex connector,
while pin 8 should be connected to the wire connected to pin 3. The easiest way to do
this is by soldering the wire, but because the pins are so small and fragile, you do need to
take care. It may test your soldering skills to get it right!
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