Simple Still Camera components?

Greetings, I am trying to design and implement a very simple camera that would capture VGA quality images and store them to flash memory such as SD or MMC. I am seeking the advice of the experienced people out there about the recommendations for a microcontroller and image sensor combination. I am looking for a fairly low cost solution since it is only a hobby. I know that I can get a cheap camera and all, but I would like to learn about it and try to implement it myself.

Thank you for your time and help.

Reply to
amerdsp
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Take 4164 in ceramic package. Carefully open the cover so the crystal is exposed. Project a light image to the crystal. Generate DRAM signals by a microcontroller. Fill DRAM with ones (or with zeroes - I don't remember). Switch off refresh for some time. Then read DRAM. You will get a pretty clear black and white bitmap picture.

Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

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Reply to
Vladimir Vassilevsky

This piqued my interest so here are a few additional references from the ClassicCMP mailing list:

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Here is an URL of a Russian-language page with details on this project:

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Here is an URL for the file 'kuckuck.zip':

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-- NOTE: the other links found for this file are all dead; if this one expires, I can post the file. -- NOTE: archive contains theory, sample code and sample images -- the images are reminiscent of the video from the Fisher-Price Pixel 2000.

Regards,

Michael

Reply to
msg

Tried that once... harder than it sounds.

Due to the disabling refresh, you can't have the chip in a computer as memory, but must build your own interface circuit.

Then you also have to play with lenses and get moderately reasonable image projection at an appropriate power desnity onto the "active" area of the die even for initial tests. You can't just shine a flashlight at it and mask off half the cells and expect to see a difference, because the output transitor when uncovered becomes a phototransistor - and that may at some light level go for the address decode logic too.

Reply to
cs_posting

I read an article yesterday from the July 16 issue of EE Times on page

  1. It dissected four still cameras with the lowest priced one a Vivitar at , yes US!!! It was only CIF format (352 x 288) but still, that is amazing! The Disney camera met your VGA requirement at and they expect this price to drop!

I would find one of these low priced units and use it for a front end with USB as the interface. You may need to use a discrete signal to control the shutter. This should be a lot easier than prying the lid off of RAM chips.

Reply to
rickman

Along those lines, the one-time-use (return to store for processing) digital cameras are $10-$20... perhaps one could be used as a source of parts, and do his own interface to the imager - since he said he wanted the experience of doing it the hard way.

If I was doing that, I'd be tempted to play with a soft core processor on an FPGA eval board, using the rest of the FPGA to do the low-level interface state machine. Though it may be possible to get a DSP-type processor with fast synchronous I/O to interface directly to an imager, and there's always the processor + FPGA/CPLD option at the expense of having to prototype a bit more of a board.

Reply to
cs_posting

For a real roll-yer-own there's a bare sensor chip

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Or a slightly more integrated module

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And a mostly complete gizmo (async serial interface, JPEG output)

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#include Just a satisfied customer. Got one of the full-up modules to package into a "critter cam" one of these days...

Reply to
Rich Webb

So where do you think image compression takes place in these low cost cameras?

On the same note, what do you think of using a PIC to do something like this? I read before that PIC's are not great for image processing because the memory is not contiguous. How about ARM, AVR? Any takes on these?

Thanks again..

Reply to
amerdsp

In news: snipped-for-privacy@r34g2000hsd.googlegroups.com timestamped Tue, 31 Jul 2007 03:12:10 -0000, amerdsp posted: |-------------------------------------------------------------------------| |"On Jul 30, 10:38 am, rickman wrote: | |> On Jul 29, 10:31 pm, amerdsp wrote: | |> | |> > Greetings, | |> > I am trying to design and implement a very simple camera that would| |> > capture VGA quality images [..] | |[..] | |> | |>[..] It was only CIF format (352 x 288) [..] | |[..] | | | |On the same note, what do you think of using a PIC to do something | |like this? I read before that PIC's are not great for image | |processing because the memory is not contiguous. How about ARM, AVR? | |Any takes on these? | | | |Thanks again.. | |-- a" | |-------------------------------------------------------------------------|

Neither a PIC nor AVR would be able to hold an entire VGA nor CIF image in addressable memory at once. They could still be used for image processing, if you are willing to work on small parts of an image at a time, or if you can figure out a way to store enough information for what you need to know about one portion of the image while working on another part of the image.

Regards, Colin Paul Gloster

Reply to
Colin Paul Gloster

Take a closer look at the AVR family and ponder the mystical abilities of an external RAM address bus. A YUV422 CIF image is 84480 bytes (NTSC) or 101376 bytes (PAL), easily and fairly transparently mappable into the AVR's data addressing space using a minimum of external glue logic.

There are probably PICs with external buses too, though I wouldn't know about them.

Reply to
larwe

chips. The low price unit uses a chip as well as an image sensor from PixArt. The other three use sensors from Omnivision and image processors from Sunplus, Syntek and "unknown" (under an epoxy blob).

I can't say if the job is doable with a PIC or not. I would want to use a CPU with more RAM than the size of the image. That means an ARM would be good. If you dig around you should be able to find some ARM boards that are built to run linux. These will have enough RAM to do the job easily.

Reply to
rickman

I don't think that low cost products are cheap to design, develop, build and distribute.

Storage is not the only issue. Microcontrollers are not fast enough to interface to a camera sensor.

Reply to
runner

So what do you suggest one use instead? Can you elaborate a little? I thought MCUs are required to store data in memory.

Reply to
amerdsp

One can buy a 3MP color sensor (with complete data available) from stock (1500+ in stock) from Digikey for $42 USD. That's less than 9 microcents/pixel vs. 230 microcents/pixel for the B&W DRAM.

That and an ARM development board would allow you to do some reasonable development.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
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Reply to
Spehro Pefhany

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CMOS sensors require data latching at moderately high frequencies,

20 Mhz - 27 Mhz, usually. A microcontroller's speed might be comparable to these frequencies, but MCU's internal fetch-decode-execute cycles reduce the speed making it too slow to keep up with pixel clocks. MCU intervention in storing image data into memory just slows down the operation. Due to the sequential nature of the image data a DMA like device is what every camera sensor is waiting for. A large FIFO is also suitable.

cs_posting's suggestion regarding FPGAs or DSPs is a good one.

Also take a look at the CMUCam3.

Reply to
runner

Go to Wal-Mart and get a cheap digital camera. Open it up and connect wires to where the pushbuttons connect. Most of the pushbuttons close a contact to ground. With the microcontroller, output a "0" to pull to ground. Make the pin an input otherwise. Let the camera take care of the interface to storage. The real cheap cameras don't have removable storage, but can download to a PC. I have been using microcontrollers to operate both film and digital cameras this way.

Don

Reply to
Donald Harris

B.G. Micro has BW cameras . no lens .

I bought them cause they are analog .

color CCD is digital .

faster to use the analog signal , into comparators

that essentially preprocess the lines , making

decissions , that would otherwise require

many lines of code .

BG Micro has front surface mirrors $1.50 .

A slow rotating BW camera , but jogging

mirrors , can get clear images , because the

difference of the movements , result in a

stationary image to the camera , so camera

has plenty time to get clear image , yet it is

rotating , and the vehicle that carries camera

is moving very fast .

My other project is WiFi , 50 km links and DS lite and GP2X A.R.M. computers . Cell phone companies will all die .

Im KC7CC , now in Guadalajara MX . snipped-for-privacy@swissinfo.org

Reply to
werty

can you give a part number for that one please? I don't see it.

Thanks

Reply to
Bill Chernoff

Maybe I am missing something, but how does $42 divide by 3 MP to get 9 microcents per pixel? I get 1.4 millicents per pixel.

I don't know the details on the 4164 DRAM, so I can't compare the two.

Reply to
rickman

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