[Tinyos-help] Can I detect sound levels with a Mica2 mote?

[Mark Bramwell]

I would like to perform a query that gives me the nodeID and the relative 
sound level of a room.  Nothing fancy or high calibration is required, just 
some returned value that is low if it is quiet in the room, higher if 
someone is talking nearby.

I see that there is a noise attribute but it always returns zero. I even 
placed the mote on top of a loud radio speaker with  no change in the 
returned values (always zero).

Perhaps I have compiled something incorrectly?  I originally installed TOS 
1.1.11 and updated to 1.1.15-Dec2005cvs-1 Everything appears to compile ok 
and I am able to query light and the voltage ok (which I assume means the 
motes work with the MPR400CB sensorboard - with onboard mic).

Some simple questions:

1. Can I query the sound level of a room?
2. Is the noise attribute the correct one to use?
3. Do I need to activate a compiler option to make it work (I noted the raw 
mic functions in the attributes file)?

Thanks for any info you can provide.  If this is a FAQ, I could not find 
it...  feel free to point me to the appropriate documentation.


MARK BRAMWELL
Senior Systems Analyst - Richard Ivey School of Business
Phone: (519) 661-3714  -  Fax: (519) 661-3485