USB webcam, interfacing with ARM cortex m3 controller

[parth_126]

I want to interface a USB web cam with cortex m3 controller
I have already arranged a USB OTG circuit on my project board
Is using plug and play camera a necessity so that I dont need camera specific drivers and will need only USB drivers ?
Do I need to load an OS on my microcontroller for using USB drivers ?
Where can I get the data format given out by webcam ?

 

[andre_luis]

Hi friends,


Sorry for posting in an old thread, however my question is exactly what was asked above.
I´m designing a system to share remotelly images acquired for a Webcam.

My first impulse was to choose an ARM CORTEX M4, in which could install an embbedded WINDOWS(CE) or LINUX.
However, I would appreciate to operate in a minimalist hardware platform, such as an ARM CORTEX M3.
( I suppose it is not so easy to run WIN or LINUX in an M3 as is in an M4 )

Does somebody could give to me seme advices regarding this task ?
I would appreciate to receive sugestions about demo application avalible at some M3 starter kit.


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[sabouras]

i think you must looking for something like that
https://www.goodluckbuy.com/alientek-ov7670-camera-module-with-fifo-stm32f103-development-board.html

 

[andre_luis]

Hi sabouras,



Thanks for reply.

However, the use of webcam is a project requirement, due we will not depend on a sigle manufacturer of a not standardized part.
Note also that OV7670 module cost is almost $20, while a Webcam can be buyed for 1/10 of this price.



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[sabouras]

ok then you choose the hard way to do that because you need to implement the usb stack and interface with the web camera.

 

[andre_luis]

I research a lot on the web and didn´t find some application example source code.
Anybody else can provide some advice ?


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[sabouras]

here is an implementation for the USB stack for LCP core m3. https://www.codeforge.com/article/71549
You could use that as base. After you need to understand the usb classes in order to understand what means the data which send the web camera and how to initialize.
https://www.beyondlogic.org/usbnutshell/usb6.shtml#StandardDeviceRequests

after all that you be able to send and receive data.

 

[andre_luis]

sabouras,


I appreciate too much your effort to help, but I´m still expecting an example applied to Webcam.

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[sky_123]

See here for information on a Linux driver for a webcam.
You could try porting the Linux driver, but it may be an uphill struggle, since the Linux driver uses
different APIs.
For that reason I don't think it will be straightforward; there may be a lot of work involved. You'd need to
examine the driver code, hope that your webcam works with that driver code, and then re-implement
any Linux-specific hooks on your specific microcontroller.