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I recently wanted to set my Axis 240 to take snapshots when motion was detected outside.
The 240 has an input connector that you can use to trigger a snapshot that is
uploaded to an ftp server (my Magnia SG20). To do this I needed an outdoor motion sensor as well as an outdoor camera. RadioShack fit the bill with a combination unit
Catalog
#: 49-2516 that works reasonably well and is very
inexpensive. Image quality is not the best, but what do you expect for a
$80.00 CMOS camera?
I found that by default the camera's motion sensor is NOT AVAILABLE to the
user. You need to purchase a separate controller box.
This would be a simple solution, but at $80.00 it costs as much as the camera
itself. The idea here is to keep the cost as low as possible.
Instead I hacked the camera's interface cable. This gave me access to
the motion sensor signal. The signal is TTL logic HIGH when there is no
motion and LOW when motion is detected. A simple circuit - two
transistors, two resistors, a diode, and a relay - gives a dry contact
output on the camera interface. I put it in a small project box, you can
even skip cutting open the camera's cable by purchasing a PS/2 mouse extension
cord and cutting into it instead. (the camera uses a PS/2 style connector at the
interface end)
PS/2 style 6 pin connector. Ground is shell.
Pins 1 and 5 are PROBABLY speaker.
Transistors are standard NPN type switching transistors.
Relay is PC Mount DPDT 12vdc 50ma coil.
Diode is just a check diode. A 1N414 works nicely.
I use the second set of contacts to light an LED to indicate activity.
You can power the circuit right from the 12vdc running to the camera.
I highly recommend you buy a PS/2 extension cord and cut it in the middle,
instead of cutting into camera cord(s).Remember: Questions
can be posted in the FORUM section !
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