MCU for 2 CMOS cameras

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What would it be the best MCU to connect 2 CMOS cameras like the OV2640 in SVGA mode (800 x 600)  at 30fps each and save the video to a uSD card?

 

MCU for 2 CMOS cameras

Last Edited: Thu. Feb 26, 2015 - 08:24 PM
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Think about the data rate. (I'm assuming 24 bit colour - that is 3 bytes per pixel):

 

800 x 600 x 3 x 30 per second.

 

That is 43,200,000.

 

So you are going to have to be shifting 43.2 MB of data per second. For 2 cameras double that. If it takes several cycles per byte then look at a processor doing a few hundred MHz.

 

I guess you are looking at a fairly high end ARM - a Cortex A processor of some sort - perhaps with a DMA controller that can help out in the data transfer.

 

BTW where is the pixel data actually going - is it to be recorded or transmitted. Can the storage device or the communications channel handle 100MB/s ?

 

Oh and this is the wrong forum - your posts is not about an AVR Freaks Project. I'll move this to "General Electronics".

 

EDIT: sorry just spotted the "uSD" in there - you are going to need class 10 cards. A high end Cortex will likely have an SD controller interface to do 4 bit data to the card. If you pick the right silicon you might find one with realtime 800x600 30fps H.264 (MP4) encoding which will greatly reduce the storage bandwidth.

Last Edited: Thu. Feb 26, 2015 - 08:26 PM
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A pair of Raspberry Pis ?

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Yes, but two Pi's are heavy for a quadcopter...

 

JC

 

Edit:

Welcome to the Forum.

Last Edited: Fri. Feb 27, 2015 - 03:13 AM
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Like many other topics the informations are not enough. we need more information of your project to good help you, Pedro.

DocJC wrote:

Yes, but two Pi's are heavy for a quadcopter...

 

Isn't this post soon for this topic?

How do you know that it's a quadcopter or drone? How do you know his drone cannot carry two Rpi?

"One's value is inherent; money is not inherent"

 

Chuck, you are in my heart!

Last Edited: Fri. Feb 27, 2015 - 12:29 PM
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Thank you for your opinions!

 

I want to make an wearable. A kind of headband with very small cameras. So I have very strict size and  requirements

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Do you have any idea what would be the right silicon for that?

 

 

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There is no such thing as "the right silicon" - Engineering is all about compromises and trade-offs between the various requirements & constraints of the system.

 

As already noted, you  haven't given anywhere near enough detail of your specific requirements constraints to be able to make any meaningful suggestions.

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My idea is to buid a headband with two small cameras that can record video to an sD card.

my idea is to make something like this http://www.ebay.com/itm/HD-720P-... on something like this: http://www.ebay.com/itm/Nike-Swo... but with two cameras

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So you need to start thinking about what are the  requirements constraints of such a system - don't you?

 

clawson has already given you an example of the kind of thinking you need to do in regard to data rates & volumes.

 

Other things you will have to consider are power consumption, size, weight, interfaces, processing requirements.

 

Then you can start thinking about how you might meet those requirements...

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I would be looking for a micro that includes image processing silicon - that is MPEG4 compression at the very least. As I say you need several hundred MHz so you are looking at something like a Cortex A8 or similar. For the image stuff either find one matched with a DSP (TI OMAP springs to mind) or one that has some kind of GPU alongside.

 

I cannot help but notice that most mobile phones these days (I mean smartphones) have megapixel cameras but can record MP4 video (admittedly at a reduced resolution). So the kind of micros that are at the heart of mobile phones could be good for this. Things like "Snapdragon", "IMX6", "Exynos", "Tegra 4", "Motorola X8". and others.

 

How much do you want to pay? I don't know but given the silicon area I imagine these processors are $15..$20 each in bulk (unless you are talking really big bulk - like 10'sof millions of units - when it could well be sub $10 - there's probably a reason why a lot of phone manufacturers (Samsung, Apple, Google(Motorola) make their own silicon for their phone designs!)

 

For a "cheap and cheerful" prototype look at using something like a Raspberry Pi 2.