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We're developing software for bluetooth devices. We'd like to test the case when the device gets out of range, but don't want to carry the device to the other end of the office for each test.
What is the easiest solution to block/shield bluetooth signals? Are there any containers that can be purchased off the shelf which bluetooth will not penetrate?
gabor
Posted 2011-03-16T17:24:56.997
Reputation: 241
15
Yes, enjoy the biscuits first, but make sure they come in a metal container rather than a plastic one.
If you have, say, a Bluetooth dongle on a USB extension lead, just cut a hole large enough for the cable to pass through the metal tin and put on the lid. You could block around the cable hole with metal foil too, but the overall signal attenuation will still be very high without this.
Conversely, you may be able to just place your device in the metal tin.
Even simpler, wrapping the transmitter (or receiving device) in metal foil will work - maybe try a nickel-coated antistatic bag:
Edit:
A colleague has just suggested putting the device on a 'variable distance transportation system':
Linker3000
Posted 2011-03-16T17:24:56.997
Reputation: 25 670
1yep, the metal container was the first thing we tried, but the device still works. will try the tin foil... – gabor – 2011-03-16T17:43:31.303
1If it's still working when in a metal container then there may be just enough leakage to give a signal - maybe even round the inside rim of the lid if its plastic coated to make it easier to take it off. You could also try a metal/nickel foil antistatic bag - one of the shiny ones. – Linker3000 – 2011-03-16T17:48:12.740
1...make sure the device inside the tin is not actually touching the inside. – Linker3000 – 2011-03-16T17:54:29.970
@gabor Try connecting the metal container to the same ground which is used by device. That should help a bit. – AndrejaKo – 2011-03-16T18:01:08.197
5+1 for the 'variable distance transportation system' – N_Lindz – 2011-03-16T18:27:53.563
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Place it next to a microwave oven and make popcorn. (Most microwave ovens emit very strong 2.4GHz noise, which is the same frequency used by Bluetooth and Wi-Fi) You might need to combine this with the Faraday cage (tin foil etc.).
geekosaur
Posted 2011-03-16T17:24:56.997
Reputation: 10 195
the microwave oven also blocks wifi and other devices nearby. plus it's kinda inconvenient in the office – gabor – 2011-03-16T17:48:56.400
1@gabor Get an old microwave oven and place the device inside. If you carefully drill holes for cables, oven's shielding shouldn't be too damaged. – AndrejaKo – 2011-03-16T17:59:04.673
2
Try, if you can, with a Class 3 Bluetooth dongle. Here's one for example. It should have range of about 1 meter (I haven't tested that one, it's just the first Google found).
AndrejaKo
Posted 2011-03-16T17:24:56.997
Reputation: 16 459
2
To use a metalic can as an RF shield, you must first ground the can through a thick short wire ground to the RF source, and then also solder the can lid at several places to provide and effective signal shield.
Walter
Posted 2011-03-16T17:24:56.997
Reputation: 21
0
Lately I've been working with Bluetooth sensors and I had to keep blocking some of them to test the others exclusively. What helped in my case was:
Two layers of tin foil (the kitchen variety) wrapped one on top of the other.
The first one did cut the signal strength but not sufficiently to block it completely. The second one did the job.
Nathan Dortman
Posted 2011-03-16T17:24:56.997
Reputation: 1
Welcome to Super User. Can you be more explicit about what to do with the foil? – I say Reinstate Monica – 2019-05-04T23:15:22.300
Did you ever solve this? – Ashley Coolman – 2016-05-22T12:53:14.047
2Maybe you could just lower it out the window on a string? – MetaGuru – 2011-03-16T17:49:20.657
3...great until it gets stolen by a passer-by! – Linker3000 – 2011-03-16T17:56:22.790