SparkFun will be closed Nov 26th and 27th for the Thanksgiving holiday. Orders placed after 2:00pm MT on the 25th will ship out Monday the 30th.



Member Since: October 19, 2006

Country: United States


Spoken Languages


Programming Languages

C, C++, ASM, Objective C, C#


University of Missouri Rolla BSEE Air Force Institute of Technology MSCE



  • A rocket

  • I purchased two of these fans to use with some 40mm square TECs. I noticed the bottom of each unit was ever so slightly concave. As a result, I was not able to get adequate thermal contact between the TECs and the heat sinks using the thermal tape listed below. If you plan to use these heat sinks, order the thermal grease.

  • Have you all considered posting transcripts for the old folks who prefer the written word over YouTube(and the folks who are at work and can’t play the video)?

  • According to Einstein, the energy density of a singularity is infinite…all i have to do is solder this wire to it.

  • I can see the error with the IRQ in the schematic. On the chip the net connected to pin 11 is named /IRQ, however the net connected to pin 5 of the header is named IRQ. Eagle didn’t connect the two pins because the nets are mislabeled.

  • I too was able to get this board working. I made the mistake of buying a $3 GoPhone for the sim card. The GoPhone sim cards are not compatible with this module. However if you go to an ATT store, they will give you a sim card for free. I was able to call the 800 number and have them register the new sim on my GoPhone account and I was in business. If I hadn’t already setup the GoPhone, I would have been able to register the free sim directly on ATTs webpage.

    The AIP server that worked for me was “wap.cingular”, no username or password.

  • Can you post some pictures of these that don’t have a white background?

  • The range problem with the radios was likely due to your choice of antennas. The magnetic base whip antennas are designed to be operated over a ground plain (i.e the roof of your car). The styrofoam box was not providing a proper ground plane for your payload antenna. In this case, the rubber duck antenna would have been the better choice (its a dipole and doesn’t require a ground plane). The big jump in range between your walking ground test and the flight day was probably because your base station antenna was on the roof of your car and not stuck to the top of your backpack. The other issue is polarization mismatch. If you mounted the payload antenna parallel to the ground and the base station antenna vertically on the roof of your car, the 90 degree polarization mismatch cost you big time. As previously suggested use a circularly polarized antenna that does not require a ground plane.
    Great project! Thanks for sharing.

  • This makes more sense than the original copper slug theory. Very interesting, thanks for sharing the story as it has unfolded!

  • What did you change to make this AHRS compatible?