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Topic: fade analog video (Read 2338 times) previous topic - next topic

videorgb01

Hi,

I am working with composite video. My goal is to get the video signal and a produce a fade off using arduino. I am reading the signal using analogRead and writing it with analogWrite. I don't know how to produce the fade. Suggestions?

Thanks for your attention.
Best

AWOL

#1
Dec 10, 2013, 11:41 am Last Edit: Dec 10, 2013, 11:43 am by AWOL Reason: 1
Quote
My goal is to get the video signal and a produce a fade off using arduino. I am reading the signal using analogRead and writing it with analogWrite

You can't read 5MHz+ bandwidth composite video with an analogRead on any Arduino, and even if you're on a Due with true analogue output, you can't write video either for pretty much the same reason.
You need to separate the positive video signal from the negative-going syncs do the fade on the video, but leave the syncs intact.
This is not a job for any Arduino.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Lakes

#2
Dec 11, 2013, 10:10 am Last Edit: Dec 11, 2013, 10:13 am by Lakes Reason: 1
Describes why (composite) video is more complicated than audio.
http://baec.tripod.com/AUGUST01/video.htm

Simpler circuit which uses an IC
http://www.simplecircuitdiagram.com/2009/11/16/video-fader-circuit/

Replace 10k pot with a digital one like this.
http://proto-pic.co.uk/digital-potentiometer-10k/?gclid=CNSA3fbqp7sCFWmWtAodQkEAnA

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