Instructables

Gumstix: GPS Stix Active Antenna Modification

Picture of Gumstix: GPS Stix Active Antenna Modification
The GPS Stix Daughter board for the Gumstix comes set up for passive antennas only. In order to get it to work with a passive antenna you need to make a small (perhaps a little too small) modification.
 
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Step 1: Cut the trace from the antenna plug to Pin 19

Take a sharp exacto knife or razor blade and cut througth the copper trace between teh antenna mount and pin 19. BE CAREFUL there is another trace that goes to pin 17 which should not be cut. Use a multimeter to test continuity between the antenna post and the pin. There should be no continuity if you did it correctly.

Step 2: Place electrical tape

Cut a small piece of electrical tape and place it so as to protect board from dropped solder and to protect against shorts once the modification is complete.

Step 3: Cut and fit the resistor

Cut the resistor's wires to the proper size and bend them so that it will be easy to place and solder. Try to fit it as well as possible. Once one end of the resistor is soldered down it is VERY HARD to bend the resistor to fit without snapping your soldering job and perhaps damaging the board.

Step 4: Practice Soldering!

I'd say this is VERY IMPORTANT unless you do a bunch of small surface mount soldering. The last thing you want to do is fry your new unit. If you are anything like me you have a bunch of old boards hanging around to practice on. I found a chip that looked similer and did a bunch of practice runs to get down my technique.

I used a cold heat soldering tool. It actually worked very well which suprised me. I never used it directly on the point of solder but rather used it to heat the resistor wire well away from the point of contact. Cold heat is neat but you need to be careful to not ever burn out your electronics by shorting the two halves of tool's tip through your board. Heating the resistor wire away from the soldering point lessens your risk of this happening.
dishanker6 years ago
Useful piece of info. Thanks. Any suggestions on where other software usage resources with the gumstix hardware are found. gumstix.net and its wiki is not that interesting at this moment :-).
afosterw (author) 8 years ago
Yah, I took the pics with a camera phone which is really crappy for close ups. I'm working on step by step pics, hopefully I'll have them up soon. I just wanted to get the info up and organized asap
Johntron8 years ago
It needs proofreading and more pictures, but still a good article.