On Thu, 17 May 2012 13:43:22 -0500, DanS
wrote:

"Gene E. Bloch" wrote in
:

On Tue, 15 May 2012 13:26:00 -0400, (PeteCresswell) wrote:

Per Dave-UK:

Could you not switch the camera on/off with a
light-sensitive switch ?

Sounds like a good fallback position - assuming the server
handles the camera's going offline/online gracefully.

It's powered via POE, so it would just be a matter of
turning the POE switch off/on.

Thanks!

An alternative to that might be to have software that
senses the state of the photocell and does a clean start
and stop of the camera program.

Luckily, I don't have to say how to do it :-)

I *would* say it's possible. What comes to my mind is
something like this: connect the photocell to an input line
on a microcontroller, and have it communicate over USB to
the computer to trigger the action.

Talk about overkill :-)


Yes....over kill.

On the right track, just not KISS-compliant.....

If the PC has a (RS232) serial port, you could easily connect
the photocell to the CTS input through a resistor divider, or a
pot wired as a resistor divider, and set it for the amount of
light needed to assert CTS. A very small and simple VB program
could be written to start/stop the camera program as necessary.
(There's usually some level of hysteresis on a PC serial port,
but if necessary, a logic chip w/hysteresis could be used as a
buffer.

Hmm, nice, but I'd still prefer to see a solution that includes a golf
ball dropping on a mouse trap. Extra points for including a series of
toppling dominoes. ;-)

Not dissing your solution, just having fun.

--

Char Jackson