Detect video signal

pcleats

Hello all,

Is there an easy way to get the BS2 to detect a video signal? All I need it to do is be able to detect a video signal, and if one is present light an LED.

Also I have seen 2 BS2's connected together, what is the MAX length a serial data signal will travel when connecting a 2 BS2's together? Someone had mentioned using·RS485 or something like that. I am·not very familar with serial communications. I will be connecting 250 ft lengths of wire up a max length of 1000ft.

Any help would be appericated.

Patrick

Bean

Patrick,
· I would use an LM1881 sync seperator. It will output an odd/even signal (as long as the video signal is interlaced) that can be measured with the BS2. The odd/even signal is a 30Hz square wave when video is detected.

· As for connecting two BS2 together, it depends on how fast they need to communicate. For slow communication (2400 baud ?) just wire will work.

Bean

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Cheap 4-digit LED display with driver IC·www.hc4led.com

Low power SD Data Logger www.sddatalogger.com

"I'm a man, but I can change, if I have to, I guess" The Red Green Show
·

Chris Savage

Another option for detecting video is to use an Op-Amp configured as a comparator.· You can detect any voltage level as a trigger on the Op-Amp and it can look like a TTL output to the Stamp Module input.

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Chris Savage
Parallax Tech Support
csavage@parallax.com