how the image is sent to the camera to the computer?

[yesil_kaya76]

Posted on August 12, 2013 at 10:32

I have a project with OV7670 with stm32f4-discovery. My OV7670 has 16 pins and without fifo.

I

'm having

a picture of

the camera and than

I have to send

my picture

to the computer. But

I have no idea

how

I'm gonna do

. Can anyone give me some direction how can I do? Thanks a lot.

[Tesla DeLorean]

Posted on August 12, 2013 at 16:02

[DEAD LINK /public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/How%20the%20image%20send%20from%20camera%20to%20computer%20Help%20me&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&TopicsView=https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/AllItems.aspx&currentviews=7]Related?

[yesil_kaya76]

Posted on September 24, 2013 at 08:17

to be migrated, sourceId: 34125:697285D7-A9CA-445D-B16C-F23BF0E3B1A3

[yesil_kaya76]

Posted on September 25, 2013 at 07:33

isn't there anyone for help

[frankmeyer9]

Posted on September 25, 2013 at 11:11

isn't there anyone for help

 

I would follow other, similiar threads, as clive1 suggested - both here and in other fora.

However, you need to understand that this kind of task is not one the Cortex M was designed for. Most professionals (and hobbyists) pick a MCU more capable to handle video tasks, both in regard to performance and memory requirements.

Something like the Cortex A5 seems more appropriate.

Sure you can handle some of those tasks with a M4, but that is always a compromise, and a rather hardware/vendor-specific one.

[yesil_kaya76]

Posted on September 25, 2013 at 13:12

thank you for your answer. I am studying about this Project since two months.

Thereof i dont want to change my processor. the Project is running. Solely, size should be VGA.  

thanks again fm.

[frankmeyer9]

Posted on September 25, 2013 at 15:42

I am studying about this Project since two months.

 

Thereof i dont want to change my processor. the Project is running.

 

Not that this comes unexpected, but:

Solely, size should be VGA.

I understand VGA as 640*480, meaning 307.200 pixel. I don't know of any M4 MCU having that much internal RAM, and of none supporting DMA to external RAM. That means you can't fetch, store, manipulate and transfer an image at once, but need to cut it into small pieces. This enforces a complex system design with several tradeoffs, opening a lot of possibilities for design and implementation bugs.

Because the additional hardware expenses for an A5 or equivalent MCU are rarely significant, most people avoid going this route.

[yesil_kaya76]

Posted on September 25, 2013 at 16:45

i am using stm32f407vg. it has got 192 kB internal RAM.

Thereof, stm32f407vg does not support VGA(640*480). I bought a CF7670C(OV7670+FIFO).

I am studying for a while But, I dont learning that how to use FIFO.

[frankmeyer9]

Posted on September 25, 2013 at 19:29

Thereof, stm32f407vg does not support VGA(640*480). I bought a CF7670C(OV7670+FIFO).

 

I am studying for a while But, I dont learning that how to use FIFO.

 

A FIFO might not help much. It is just a intermediate buffer, to ease otherwise strict syncronization requirements between data source (camera) and data sink (stm32f4xx).

If you want tp process still images, you might even go without it. Real-time performance (video-like frame rates @640*480) is out of reach with this setup, even with FIFO.

I don't know the details of your project, so I can't judge if it appears feasable, or not. But I can try to expain why I would choose another hardware platform, and not a Cortex M4.

I am studying for a while But, I dont learning that how to use FIFO.

 

Studying and understanding datasheets is crucial part of embedded software business.

[David Littell]

Posted on September 26, 2013 at 01:41

Black and white would require only about 38 kB, right?  Grayscale goes from there...

[yesil_kaya76]

Posted on September 26, 2013 at 15:28

thanks alot fm for your suggestion. I found a new way for VGA format. I captured two pictures from camera without FIFO. After i combined this pictures as follow.

But, there are a problem. i dont removed black line in the middle of the Picture.

Black end White is a good idea. But as far as I know, camera does not support grayscale.

it supports just; YUV, RGB and RAW.