Starting a Webcam Driver? - Hardware

This is a discussion on Starting a Webcam Driver? - Hardware ; Hello Everyone, I have an Acer 5100-5022 and my integrated webcam simply doesn't work and there is no viable driver for it. So, I've decided to take the plunge and not only play around with writing device drivers but to ...

+ Reply to Thread
Results 1 to 3 of 3

Thread: Starting a Webcam Driver?

  1. Starting a Webcam Driver?

    Hello Everyone,

    I have an Acer 5100-5022 and my integrated webcam simply doesn't work
    and there is no viable driver for it. So, I've decided to take the
    plunge and not only play around with writing device drivers but to
    write a useful one for this camera as I learn.

    So, my question is: can anyone recommend a good book (ebook preferred)
    or website that discusses/teaches how to write webcam device drivers
    for Linux?

    Thanks in advance...

    Anthony

  2. Re: Starting a Webcam Driver?

    Anthony Papillion II wrote:
    > So, my question is: can anyone recommend a good book (ebook preferred)
    > or website that discusses/teaches how to write webcam device drivers
    > for Linux?


    You could really do with a technical reference manual for the device. I
    would first jump on the manufacturers website, to see if such
    documentation exists, or if not email the manufacturer.

    Writing device drivers without technical reference documentation is not
    easy.

    Regards,

    Mark.

    --
    Mark Hobley,
    393 Quinton Road West,
    Quinton, BIRMINGHAM.
    B32 1QE.

  3. Re: Starting a Webcam Driver?

    Anthony Papillion II (papillion@gmail.com) writes:
    > Hello Everyone,
    >
    > I have an Acer 5100-5022 and my integrated webcam simply doesn't work
    > and there is no viable driver for it. So, I've decided to take the
    > plunge and not only play around with writing device drivers but to
    > write a useful one for this camera as I learn.
    >
    > So, my question is: can anyone recommend a good book (ebook preferred)
    > or website that discusses/teaches how to write webcam device drivers
    > for Linux?
    >
    > Thanks in advance...
    >
    > Anthony


    Since Linux is open source, you start with an existing webcam driver (or
    maybe more than one to synthesize from them) for the basic layout.

    But the key thing is the hardware. If you don't know anything about it,
    then you can't write software to deal with it. You need to know what
    the camera expects in order to be able to control it. This is usually
    the stumbling block that keeps certain hardware from being useable with
    Linux. The specific manufacturers decide there isn't a good reason to
    release the technical details, so it's not just a matter of writing a driver,
    it's a matter of figuring out what has to be done by that driver first.

    I don't know how people writing Linux drivers do it for the hardware
    where the details are not available. But I know I've done things in
    the past such as dissassemble code to extract information on how a serial
    port addresses a smart peripheral. Kind of tedious, because there's
    usually a lot of code that is irrelevant, but you have to wade through
    it to find the specific bits. I guess in that case it would have
    been smarter to put another serial terminal in parallel, to capture
    what was sent from the serial port to the peripheral.

    In the old days, figuring out hardware was fairly simple, because
    the hardware was simple and used familiar components to build up
    the whatever. Now, when it's all integrated into one complicated
    IC, you don't have access to a lot of the hardware and there's no
    familiar components to guide you to the unfamiliar.

    Sometimes you can be lucky, a given device is merely a variant
    of an existing device that does have information (or a driver), and
    if you can make a good guess, you impose the guess on the situation
    and see if you can prove it. "That IC in that webcam is almost
    the same number as the IC in that other webcam, so if I use
    the driver for the first one, will it work for the second?" And
    if it does, then maybe you will be lucky and only need to fiddle
    with tiny bits.

    AN existing driver will give you the form. And assuming the
    webcam uses USB, then the basics of how to interact with the device
    over USB will be covered. You then "merely" have to look at what
    needs to be sent to the webcam via USB and what it expects back.

    Michael




+ Reply to Thread