Re: Glass breaks, thunderstorms and HA (was Re: Help with 7 Circuit Project?)

[Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Wed, 20 Jul 2005 18:42:38 -0400, "Robert Green"
<ROBERT_GREEN1963@xxxxxxxxx> wrote in message
<GoSdncpLHtWESUPfRVn-gQ@xxxxxxx>:

>
>Yes, in actuality, many of my CCTV cameras have built in audio that feeds
>back to a central panel in the basement.  It wouldn't take much to take
some
>samples during the storm and decided what level to use to make the
>determination "either thunder or WWIII is occurring."  If I understood what
>I read (I think by Marc) the HAI panel will not be particularly useful in
>creating a "audio storm detector" because it does not have analog inputs.
>But I believe I can accomplish that part of the task with the CPU-XA.  I
>simply need to send a signal to the HAI to indicate a possible storm in
>progress and a timer to reset that flag once no thunder has been heard for
>X-minutes.


As long as you don't need to do numerical computations on the analog inputs,
and simply use the controller's software to detect a threshold (i.e., a
specific value that when exceeded triggers an effect; "IF volt > x THEN etc
")  you can accomplish the same thing in hardware _externally_ with a simple
voltage divider formed by two fixed resistors or a pot and an opamp (or
transistor, comparator or TTL or CMOS digital IC) to shift the level to the
desired on/Off values (0 or 5vdc; 0 or 12vdc etc.). The usefulness of the
analog input depend in large part on the software/firmware of the
controller.

>> > I'm just not sure of how to process those sound
>> > events into something I can feed into to HAI Omni
>> > LT to tell it "take it easy, it's only a storm."

Well there are surely many ways. For example CyberHouse has a client called
"Listen" that can be trained to listen to an audio signal and alert the
CyberHouse server when that pre-identified audio signal is heard. This can
be a washing machine,  noisy water valve, doorbell, Trouble is that thunder
is not a single sound

 http://freesound.iua.upf.edu/tagsViewSingle.php?id=951 shows some sonograms
of thunder that confirm our qualitative assessment that thunder has
different so it may be difficult to train the software to 'hear' lightning.
(I dunno.)

But because because thunder is caused by lightning, it might be practical to
detect the lighting that causes the thunder and simply disregard glass
breaks when lightning is indicated in your area on the www or if your
lightning detector goes off.

The topic of lightning detection has come up before in the context of
powerline surges/outsges in this newsgroup (Goggle).

Marc
Marc_F_Hult