Interacing a small cmos camera module to a PIC

[dak246]

The camera is a 1/3" color cmos with a 300 line resolution and I want to interface it to PIC16f877a. I have a spec sheet with the pinout for the camera so thats not a problem. Ideally I want to feed the output from the camera into the PIC, store it in external memory, and then relay it to my PC later. I think real time transfer will just make this more difficult than it already is. I know I wont be able to use EEPROM, I tried unsuccessfully with audio before. Any ideas on what to do here? Do I need a simm stick interface or some alternate type of memory, or do I need to directly send the feed to my PC via serial connection? Any ideas here are welcome.

 

[Nigel Goodwin]

The camera is a 1/3" color cmos with a 300 line resolution and I want to interface it to PIC16f877a. I have a spec sheet with the pinout for the camera so thats not a problem. Ideally I want to feed the output from the camera into the PIC, store it in external memory, and then relay it to my PC later. I think real time transfer will just make this more difficult than it already is. I know I wont be able to use EEPROM, I tried unsuccessfully with audio before. Any ideas on what to do here? Do I need a simm stick interface or some alternate type of memory, or do I need to directly send the feed to my PC via serial connection? Any ideas here are welcome.

Have you considered the bandwidth and storage required?, just to read and store a single frame!.

Assuming 3MHz bandwidth from the camera, you need to take around 10,000,000 samples per second - and store them somewhere?.

If you couldn't do it with audio, with 20KHz bandwidth, how do expect to do it for video with it's much greater requirements?.

 

[pike]

good god :shock:

You need atmel devices my man!! PIC's wont cut it!! Atmel might on the otherhand.

good luck!!

 

[Nigel Goodwin]

good god :shock:

You need atmel devices my man!! PIC's wont cut it!! Atmel might on the otherhand.

The top end Atmel devices are only the same sort of speed as the top end PIC's, none are anywhere near fast enough for real time video digitising!.

 

[samcheetah]

have a look at the following AVR project

**broken link removed**

 

[Nigel Goodwin]

have a look at the following AVR project

**broken link removed**

Impressive!.

But it's not using a video camera, it's using a 'colour image sensor', and it's fairly low resolution. Because it doesn't generate a video signal, you don't have any problems digitising the analogue output (because there isn't one).

 

[zevon8]

As has been mentioned, the video is going to require massive amounts of storage, even recorded as jpeg stills. If it is going to end up on a PC anyways, I would just use a capture card, say one of the conexant chip based cards, and feed it directly with a camera.

These cards are very cheap, and they have plenty of software already written, including developement kit that will interface with windows, netmeeting, etc.

Chips such as the BT878 are commonly used on these cards. ATI uses the same family on its AIW cards.

 

[dak246]

My fault...I didn't fully describe what im trying to do. Im not considering capturing streaming video, but rather a still image, then either save the image to external memory or transmit the image to my PC ( but Id rather save the image ). Where I said "feed" i was referring just to the output from the camera, not neccesarily a video feed. I have considered how much space I need, which is alot, but my question is whether or not this is doable. If im correct, I would need 8x300x200 bits ( assuming its 300x200pixels and 8 bit color ) for each picture, so a couple MB should be able to store at least a few images. Im assuming by everyones responses that MB's of memory may not be feasible? The module gives digital output so i shouldnt need to process it. When I attempted audio I was attempting to save real time streaming audio into eeprom, and Im guessing the read/write couldnt keep up. Anyway, is my picture saving idea possible? Basically I want to mount this into a model rocket without having to set up a radio link. Then upon recovery link it to my PC with the serial cable and download the images. Thanks for the help thus far.

 

[bmcculla]

You could use a CPLD to grab data from the camera and store it in a RAM chip. A microcontroller could then read the frame from the RAM and store it in some cheap NAND Flash for later readout. This would require a bit of digital logic work for the CPLD but speed wouldn't be a problem.

Color images are usually 24bits per pixel (8 bits for each color). Your image would probably be fine if you only saved the first 4 bits of each color.

 

[RAJ.MIRK]

can some one tell as to how is it possible to hack usb camera and takeout the cmos from inside ad use it in this
project .