Then use the safety pin idea for final assembly. Thanks very much Mr. Naoya. The outside pins are for power. The inside pins are for data. Ground is shared for both power and data.
Data out has a round shiny mark near it.
When someone offers us some power supply ideas I'll add them here. Several people have told me that a dead mouse tail makes a great cable. 0.15V. I also hear the eTrex uses a MAX 1677 DC-DC converter chip inside. If the external supply voltage goes lower than 2.8V then the internal batteries are used. I've received several power supply designs.