Re: [PARPORT] Parallel port ioctl()

From: Tim Waugh (
Date: Tue Feb 25 2003 - 05:48:12 EST

  • Next message: Uwe Bonnes: "Re: [PARPORT] Parallel port ioctl()"

    On Tue, Feb 25, 2003 at 09:58:31AM -0000, wrote:

    > I have written a bespoke ioctl() to communicate with a laboratory testing
    > device (length of wool fibres). It only partly works because, I think, the
    > kernel parallel port driver/module is clobbering it:
    > If I toggle the input _ACK line low, without my code running on LINUX, the
    > _STROBE output toggles with it. Not quite in sync, there's a ca. 5uS delay.

    That sounds like there might be something trying to talk to a printer
    on that port. Something in the printer queue?

    Incidentally, you might want to take a look at libieee1284 for
    communicating with your device. It'll save having to recompile the
    kernel and reboot each time you find a mistake in your code.


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