[geeks] Looking for a simple user-interface device

Dave Kimmel crisco_kid at shaw.ca
Wed Apr 24 21:51:55 CDT 2002


On Wed, 24 Apr 2002, Jonathan C. Patschke wrote:

> > just from reading FreeBSD manpages (iic, iicbus, iicsmb, smbus) for a
> > couple minutes, so I could be completely wrong.
>
> SMBus is almost always I2C.  I didn't think of that, and I'm completely
> ignorant about it, but that sounds like a decent use for it.

I think the biggest problem would be figuring out how to hook it up.  I
can't recall seeing an SMBus port on any of my motherboards.

> > In FreeBSD, there are I2C drivers and access is done through a device
> > in /dev.  I don't know if FreeBSD is your operating system of choice
> > or not,
>
> I was thinking probably OpenBSD.  FreeBSD's certainly not out of the
> picture, though.  I really like OpenBSD's new firewall code, but I don't
> know what the state of the I2C code is.

I just took a peek at the OpenBSD manpages - it doesn't look like there's
any I2C related stuff in there.

> > and I don't know what other OSs will let you do with the SMBus.  If
> > I2C isn't an option, you'll probably have to run a serial cable to one
> > of the ports and (optionally) glue it in place or something.
>
> Yeah, or connect it to the internal half of the port via a wire harness,
> and then cap the outside of the port.  That'd be messy, but effective.

This would probably be less messy than running a cable to the outside of
the box though.  If you could find a motherboard with one external serial
port and a header for the second, that would be perfect.

> > I'm playing with one of the LCD displays and think that you might be
> > able to do the keylock by making the lock a key on the keyboard grid.
>
> That'd be nice and easy, just wire the two leads of the keyswitch the the
> keyboard grid.

Hopefully it will work.  The display will send keyup/keydown, but I don't
know if it will let you have multiple keys pressed.  I'll play around a
little with my LK204-25 and see how all that works.

-- Dave Kimmel
   crisco_kid at shaw.ca



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