Store › Forums › Video Experimenter › Bugs/Problems › Not displaying anything
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Michael.
 
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August 4, 2012 at 5:38 am #409
crazybutable
MemberI assembled the kit and the video passes through, but I cannot see any output video, even when I set the switch to sync only. No amount of potentiometer twiddling helps. I tried the first two sketches on the project page and neither of them worked.
Thoughts?
August 4, 2012 at 1:00 pm #1038Michael
KeymasterHi crazybutable!
Did you use the specialized version of the TVout library that is on our web site?
August 5, 2012 at 12:20 am #1033crazybutable
MemberYep!
August 5, 2012 at 2:49 am #1034Michael
KeymasterAnd the jumper is set to the V.SYNC position?
If so, then something else is wrong. Check the soldering connections (you probably already have). Or I can check out the device since you are local 🙂
August 5, 2012 at 6:03 pm #1035crazybutable
MemberYes, I checked the soldering connections, that was my first thought, that maybe I had forgotten a pin or something.
And it doesn’t matter what the jumper is set to.
I’ll send you an email about when we can get together.
August 6, 2012 at 4:26 am #1036crazybutable
MemberGot it working. On a whim I tried it with a different Arduino and this time it worked. (actually it gave me a bunch of digital hash at first, but with a little monkeying around I got it working.)
I’ll have to put that Arduino off to the side. One of the pins is probably bad on it. (Off the top of your head, do you have any idea which arduino pin, if it was to be missing, would cause the VE shield to fail like that?)
So now I have a new question. In the video frame capture example, when you call tv.capture, where does the captured frame go? I’m trying to trace where the data ultimately winds up, and am I right in my deduction that it all winds up going through that assembly language code in video_gen.cpp?
Is the final data available in the TVout framebuffer, and if so, can I get access to the framebuffer from the same scope that I called tv.capture from? Or do I have to create my own method in the tvout library to gain access to that data?
Thanks.
August 8, 2012 at 2:37 pm #1040Michael
KeymasterThat’s weird — sounds like you have a bad pin on that Arduino. The Video Experimenter uses pins 2, 6, 7, 8.
The pixels in the TVout frame buffer can be accessed with [tt:3mbklmw6]tv.get_pixel(x,y)[/tt:3mbklmw6]. The entire buffer is available as the array [tt:3mbklmw6]display.screen[/tt:3mbklmw6].
See the code in the computer vision project for examples of reading/manipulating the frame buffer.
http://nootropicdesign.com/projectlab/2011/03/20/arduino-computer-vision/ - 
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