Best way to get VGA into AVR

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#1
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hi,

i am searching for a solution to read out the Video signal of a standard monochrome VGA Camera, and then to store the picture into an external EEPROM or something else.

what are the best AVR for this problem, and would it better to use an external ADC?

any tip would be great, also links about existing solutions

regards
sky

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An AVRfreaks site search on camera leads to lots of results, first relevant being:

http://www.avrfreaks.net/index.p...

Smiley

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Quote:
what are the best AVR for this problem, and would it better to use an external ADC?

If you are talking analog VGA, it's probably much to fast to handle with an AVR. What exartly are you trying to do, make a framebuffer?

-Colin

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An eeprom would be far to slow as storage medium you need to look at grabbing into ram then downloading to flash

Keep it simple it will not bite as hard

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Also, if you don't do something to compress the video then even VGA (640x480) in mono (presumably 256 grey level = byte per pixel) is going to generate a LOT of data for flash storage. 640x480 is 307,200 bytes per frame. At what, 15 fps?, that's 4.6MB per second. So even a relatively large flash device (1GB say) is only going to be able to store 223 seconds = about 4 minutes of video.

If you start looking at video compression (MPEG?) then you are going to need something way more powerful than even the fastest AVR

Also video processing tends to equal "lots of RAM" and that's something AVR's typically don't have.

Maybe AVR isn't the right micro for the job?

Cliff

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Do a search for CMOS camera modules on google, I've found a couple out there (some reasonably price sorry don't have the link right now) that allow VGA capture directly to jpg that runs in a serial bus. As far as using an AVR to directly digitize analog video. Not gonna happen, not sanely at least.

-Curiosity may have killed the cat
-But that's why they have nine lives

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i'm sorry for my bad discription

i want only capture one picture (no videos), and then process it (store into some space), and if needed sent via UART to PC

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Skystalker wrote:
i want only capture one picture (no videos), and then process it (store into some space), and if needed sent via UART to PC

I fear your problem may still be the "(store into some space)" in there. If you mean RAM you are going to be hard pushed to find an AVR with sufficient for even a single frame buffer though I guess you may be able to process it one scan line at a time?

'course that depends what you mean by "process" in the above!

Cliff

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Do we have a chip which converts video input into controlled digitize output.

Say i pull one pin high of this chip and it send me a frame

Regards, Kapil +) ISP lines on MEGA128 NOT mapped on SPI +) Tiny4/5/9/10, Isolate Reset line from ISP before connecting it to +12V

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The dazzle frame grabbers worked on a printer port. You wait for vertical sync, then grab one line. Then you wait for vertical sync, grab line 2. So it takes 262 frames to grab a picture. I guess this works ok if the video is a steady picture.

Imagecraft compiler user

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There was a project recently in Circuit Cellar that did something like you require. And it used an AVR.

http://www.circuitcellar.com/avr...