Tiny bluetooth teardown

minibluetooth

The folks at SparkFun were startled by how small USB bluetooth adapters had become so they split one open. They noted a few interesting design features. It has a small folded trace antenna on the board edge. The metal USB housing acts as the RF shield. The bluetooth IC is an AS3620QA. Now we wonder what those tiny Buffalo drives look like inside.

Related: Eye-Fi teardown, storage/WiFi in an SD card

38 thoughts on “Tiny bluetooth teardown

  1. “Now we wonder what those tiny Buffalo drives look like inside.”

    -Please wonder no more! Crack one open, for education sakes of course.

  2. The only bad part about these bluetooth devices is that the led tends to be green instead of blue, and is placed on the underside of the board, so if you are using it on a laptop, it makes it impossible to see the light.

    Also, white versions cost like 20 times more. The regular black version can be had for like 2.30 ~ 3.00 with free ship on DX or ebay.

  3. I have one of those. Bought it for like 3 bucks with free shipping and works on my Desktop as well as my iBook.

  4. Wait don’t they know that kinks in an antenna aren’t good? At least that’s what my engineering class said. Curves are much better because they don’t restrict electron flow.

  5. They got the part number wrong. If you zoom in on the picture that is on the sparkfun website, it says a53620qa not as3620qa. I still couldn’t find a datasheet though.

  6. I got the same bleutooth stick only problem is it won’t work in Vista 64bit, can’t installe any drivers.

    And i’ve try’d a lot the damn thing is in the bin now.

  7. @kyndal: please god no I’m tired of seeing adruino stuff flood these sites. Nobody is making or reversing anything they’re just interfacing and coding.

    That one guy is right about the square antenna, but it’s not going to matter with this application much. The also use too many passive components

  8. @kyndal shut the fuck up.

    @tjhooker he is trolling.

    This is impressive. Next step, bluetooth on a Mini-B connector for plugging in OTG devices.

  9. @terreurbv, you should have removed Windows and kept the Bluetooth.

    The device works well on 64-bit versions of BSD and Linux.

    Goof.

  10. “Now we wonder what those tiny Buffalo drives look like inside.”

    BGA or epoxy’ed flash on one side, BGA or epoxy’ed “usb mass storage controller” on the other. Exicting stuff!

  11. @Yrb No worry Got a new one (destroy the old one out of frustration) and i’m using Linux.
    Only have Windows for PS and AI… :/

  12. @alan- fwiw, i believe they did that as a type of coil similar to what they use in walkie talkies.. 2.4gig antennas dont exactly need to resonate long distances with bluetooth so its now a major concern as small as it is

  13. I bought 5 of these for about $2.50 each delivered on ebay a while back, and they work quite well. The only thing I didn’t like is the fact that the placement of the regulator prevents the plug from fully seating in many usb sockets, so there is a bit of exposed metal connector, and the plastic housing does not become flush with the casing of the host device, which partially defeats the purpose of making the plastic casing round instead of square(so that it does not snag and break when hit from the side)…

  14. I’ve accidently put one of these through the wash a few times.

    After letting it dry thoroughly it still works ok.

  15. I got one of those for $1.72 off ebay last week, and promptly tore it apart. Really amazing how tightly packed everything is. Reassembled, and works great. Insane how things can shrink down.

  16. @ allan – “Wait don’t they know that kinks in an antenna aren’t good? At least that’s what my engineering class said. Curves are much better because they don’t restrict electron flow.”

    Actually, the reason kinks are often avoided is because they tend to generate rf as a result. in a conventioanl pcb design you’d want to avoid this, but for an antenna it’s exactly what you want.

  17. @allan to expand a little more on what agant420 said the kinks in this particular application are intentional and act as a resonator. That’s a tiny tiny one though, looks smaller then 1/4wave so i’m not sure what it’s tuned too.

  18. Looks like this one needs some help from a dremel to cut the USB plug a little shorter and to cut the sides off that huge handle…

    My bluetooth adapters are smaller than this one.

  19. If you cut the corners off you run the risk of it getting hooked on something, the roundness isn’t a bad idea probably, you don’t want dongles on notebooks to get hooked in the bag as you take them out.
    btw, I noticed the contacts are all the same length, weren’t the power ones originally suppose to be longer according to USB specs so the power is established before the data lines connect?

  20. walt:didn’t know that was a feat worthy of being on the interwebs.

    I like to see more cracked devices than arduinos. maybe 1 day we wil find an arduino in a kids toy. 8(

  21. It isnt really dificult to open them, just some pressure and crack! open!, if you can trace an internal usb port in your mb this lil thingos make for an excellent internal bt module.

    “I like to see more cracked devices than arduinos. maybe 1 day we wil find an arduino in a kids toy. 8(”

    lol that would be amazing. >:)

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