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[?] Looking for a small Bluetooth radio-microphone.

Does anyone in this NG know of any company that markets a fairly small short-range radio-microphone using Bluetooth technology?

I'm fully aware of the two-way Bluetooth hands-free mobile ear-hangers but, since they all have the ability to receive as well as transmit, they are somewhat overcomplicated for my purpose.

I'd like a very small basic speech transmitter capable of sending one-way speech using Bluetooth over a distance of no more than 5-10 meters, and a suitable receiving arrangement to go with it, of course.

Ideally the transmission system should have some level of speech security (frequency hopping ?) to protect against monitoring by any other Bluetooth equipped user.

If I can't find any suitable product that already exists, my Plan B will probably be to build one using off-the-shelf Bluetooth modules. Does anyone have any suggestions/recommendations regarding the best modules to use for this application?

Many TIA - Dave

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David C.Chapman - (dcchapman@minda.co.uk)
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Reply to
David Chapman
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I suspect the easiest approach would be to get an off-the-shelf Bluetooth audio adapter (e.g.,

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and hook your microphone up to it (you'll need an op-amp or similar to get your microphone's output level to line level is all)... and then use any old Bluetooth headset (e.g.,
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) for the output, tapping into the audio output lines.

Anyone trying to eavesdrop on your conversation with need to either pair with your transmitter (that presumably you won't allow, as this generally requires physical access to the transmitter to initiate the pairing process) or else just needs to brute-force (attempt to) break the encryption used (note that Bluetooth already uses frequency-hopping, but I don't know whether or not the hop sequence is "obvious" even if you're not paired). I haven't heard that this is readily doable, so you're probably OK -- I expect that people successfully hacking into Bluetooth headsets so as to "bug" phones would be pretty big news, whereas my recollection so far is just that some phones are vulnerable to having their phonebooks, SMS messages, etc. "bluesnarfed."

---Joel

Reply to
Joel Koltner

I doubt you'll be able to build anything cheaper/slicker than a $20 COTS BT earpiece. Unless you have some other criteria that renders that approach inappropriate (e.g., longer battery life), why not just fill the "ear" (speaker) portion with epoxy (if you are dead set against it *receiving* anything) and just use the mic?

Reply to
D Yuniskis

You can get cheap bluetooth transmitters that attach to MP3 players

e.g.

USB Rechargeable Bluetooth Audio Transmitter Dongle (3.5mm Jack) Price: $20.78 free shipping

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Adrian C
Reply to
Adrian C

On a sunny day (Thu, 6 May 2010 16:48:31 +0100) it happened David Chapman wrote in :

Some year ago I used my Nokia what you call 'earhanger' to talk to the Linux PC. I got it working only one way :-) ALsa latest version, dbus, some cheap Bluetooth USB module so mall you can hardly see it when plugged into the USB. Maybe they fixed Alsa now so it works 2 way. BTW it worked 2 way in MS xp.

Reply to
Jan Panteltje

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