Can you sense me now?

March 20, 2007 7:39 PM

Can I purchase, or easily make a bluetooth keychain device which I can detect with my laptop?

So, I'm desperately inspired by the idea that my computer can lock/unlock and do other stuff based on my presence - or, specifically, the presence of a bluetooth device. However, my cell phone doesn't do bluetooth.

Is there some sort of small device that I could buy and attach to my keys that simply transmits its ID over bluetooth? Failing that, is there some sort bluetooth product I can buy and take apart to get at the bluetooth chip for this purpose? My main concern with this strategy is a power supply. I'm not a technical/electronic wizard, but I could probably handle something that required only a little soldering.

Any help with this personal project of mine is appreciated!

posted by bkudria to computers & internet (7 comments total)

Wireless PC Lock? Not bluetooth, but it's pretty hackable.
posted by niles at 8:00 PM on March 20, 2007

I'm not sure if you came across this idea due to a post on Engadget today, but this is the link they provided to a gentleman who configured his Mac to recognize when his bluetooth cell phone was near.

When not in range the screen saver with password would be activated. When in range the screen saver would turn off.

If you understand applescript you can do a host of other things using this technique as well.
posted by ASM at 9:16 PM on March 20, 2007

niles: I did see that, and thanks for the hackaday link. There are two downsides to this solution: (1) It takes up an additional usb hub (my laptop has BT built in) and (2) all the Linux drivers I've found require patches to to the kernel. (translation: the drivers are a pain to install and keep up-to-date). Thanks anyway!

ASM I actually saw it on Lifehacker, and yes, I was planning to write a small script to do lots of things - except not on a Mac.
posted by bkudria at 9:45 PM on March 20, 2007

I read the lifehacker article recently too. The proximity program is already installed on my Macbook! It works really well, except my phone seems to fall asleep after some time and then my Mac locks itself!

Anyway, to answer your question, I've heard of a lot of people buying a cheopo Bluetooth headset for just the reason you describe. If you already have bluetooth on your PC, this might actually be the cheapest option! I'm sure you could find a small one you can take apart if you want to make it smaller (maybe from a pawn shop?)
posted by ranglin at 3:25 AM on March 21, 2007

ASM et al: Just as an aside, I used to use a program called BluePhoneElite to do this, but it is not freeware and it ran out of evaluation period. The reason I mention it though is that, if you go to the BPE website, you can find scripts for lots of different things applescript can do, like launch iSync, set away messages on IM programs and even talk to you using the speech synthesizer (my Mac currently says "Locking Computer" when I walk away from it)!

(Not that this helps the OP if he is on Linux, but thought it worth mentioning for the thread).
posted by ranglin at 3:28 AM on March 21, 2007

I got a usb bluetooth device from my mac. My cell phone has bluetooth, which I leave off. When I want to transfer things, just turn bluetooth on. When done, turn it off. Works easily and is secure.
posted by The Behatted Wild Man of Greenfield at 7:31 AM on March 21, 2007

ranglin: Yep, I ended up doing this. There was a cheap bluetooth headset on Woot.com today, I'll
see how far I can get with it.

As for what to make the computer do, I'm not sure I want mine to talk to me, but I plan to have it start the screensaver, lock, set the IM away message, pause movies/music, and write to a log file, at least.

Thanks for the tips, all!
posted by bkudria at 9:35 PM on March 21, 2007