AVR-Chat

You're looking at using a dedicated ADC chip here.  The fastest ones are 
parallel out, but the newer SPI based ones are also pretty fast.

DLC

kernels_nz wrote:
> Hi guys, I have a curly one, any creative suggestions would be
> appreciated.
> 
> Im interested in digitzing a B/W video waveform from a standard CMOS
> security camera, im only really interested in one line of video but
> the conversion time of the average AVR A2D is around 13-50us but the
> whole video frame is around 50us. 
> 
> I know I can overclock the AVR A2D to around 1MHz, but that still
> would only give 4 conversions per video frame.
> 
> So, a few ways that I could see around the problem is:
> 
> 1. Faster external ADC -> Not ideal because it adds cost, componets
> and it's hard to get hold of Megasample ADCs. Also, having a fast
> external ADC is useless unless you can communicate with it at super speed.
> 
> 2. Slow down "time" somehow so that I buffer a frame of video
> "somehow" and convert it at my leasure using the inbuilt ADC. <- This
> method requires "magic" and im not sure what type ? maybe someone has
> come across some way of doing this ?
> 
> 3. Use some of the "line" cameras that allow me to clock the video
> data out pixel by pixel. <- I can do this, and we even have the
> cameras available @ work, but I would prefer to use a off-the-shelf
> cheap video camera.
> 
> Any other ideas?
> 
> Thanks !
> 
> Hein B
> Auckland, New Zealand.
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 

-- 
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Dennis Clark          TTT Enterprises
www.techtoystoday.com
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