Re: [rtl] Joystick

[David Olofson <david.olofson@reologica.se>]

Mon, 13 Nov 2000 Sundeep Kapila wrote:
> Hello,
>      I want to read input from a joystick (attached on a game port)
> 	 as a real-time periodic process. Can someone give me pointers how
> 	 and where to start ?

linux/drivers/char/joystick

NOTE: Standard PC joystick interfaces suck, as they require busy waiting for
accurate reading. If you want a solution that allows you to read the stick
without wasting cycles, look for something that uses a different interface, or
some sound card (or possibly main board) with a joystick interface with *real*
ADCs; not CPU driven capacitor discharge measurement style crap.

> 	 I also want to read input from the keyboard as real-time.
> 	 can this be done ?

linux/drivers/char/pc_keyb.h
linux/drivers/char/pc_keyb.c

It's probably a good idea to hack the driver in a way that allows "standard
Linux" to use the keyboard as well, when your RT application isn't using it.
But you could remote control your system over a network, of course - you
wouldn't need the local keyboard in that case.


//David

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