Smallest wireless solution for ~5 feet?

FlyingFishFinger

Hi all-
I'm looking for the smallest possible set of wireless chips that can communicate across a distance of about 5 feet (possibly through an enclosure). The protocol doesn't matter, but it should ideally be smaller than the RN41 Bluetooth modules. Does anyone have any ideas? This is for a sensor monitoring board inside a drill at the end of an arm that just needs to communicate back to the base of the arm.
Thanks for any pointers [noparse]:)[/noparse]

Rafael

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UC Berkeley '12 EECS
CalSol: UC Berkeley Solar Car
http://calsol.berkeley.edu
KJ6AWU

Phil Pilgrim (PhiPi)

Is it line-of-sight? If so, how about IR?

-Phil

FlyingFishFinger

No it's not line of sight, unfortunately. I already suggested that, it didn't resonate too well. We can't even run wires to it, so it also needs to have power on board (at least for this version). I'm thinking a small Li-poly pack like the use in RC planes, but for the moment I'm just supposed to come up with something feasible.

Rafael

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UC Berkeley '12 EECS
CalSol: UC Berkeley Solar Car
http://calsol.berkeley.edu
KJ6AWU

Leon

The Nordic nRF24L01+ chips are very small. Most wireless mice and keyboards use them. I know someone who gets one of those and an MSP430 chip in an incredibly small unit.

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Leon Heller
Amateur radio callsign: G1HSM

FlyingFishFinger

That sounds good. I need to design a doughnut-shaped PCB so we have some funny real-estate, so maybe I can get the chip itself from Nordic. An MSP430 is completely overkill though. If I can get hold of them, I'll probably redesign something like this into the right shape:
http://www.sparkfun.com/commerce/product_info.php?products_id=691
Thanks!

Rafael

EDIT: Sparkfun has it. Awesome!

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UC Berkeley '12 EECS
CalSol: UC Berkeley Solar Car
http://calsol.berkeley.edu
KJ6AWU