Switch to indicate ebook mode

Jordan Crouse jordan.crouse at amd.com
Mon Dec 18 12:23:17 EST 2006


On 18/12/06 17:53 +0100, Bert Freudenberg wrote:
> On Dec 18, 2006, at 17:35 , Jordan Crouse wrote:
> 
> >On 17/12/06 20:50 +0000, Chris Ball wrote:
> >>>>On Sun, 17 Dec 2006 13:05:52, Dan Williams <dcbw at redhat.com> said:
> >>
> >>>I can't remember if I ever got a straight answer on this.  Is there
> >>>a switch somewhere that we can access that indicates whether or not
> >>>the laptop has been swiveled into ebook mode?
> >>
> >>This is <http://dev.laptop.org/ticket/467>.
> >>
> >>>Ideally, the switch would generate an interrupt which we could
> >>>receive and automatically rotate the X display and switch to B&W
> >>>mode when the keyboard is hidden [1].  It's not a great experience
> >>>to have to expose a toggle somewhere if we can't figure out when
> >>>we're in ebook mode, especially if we had to rely on activities to
> >>>provide that toggle in their own UI.
> >>
> >>Yeah, it looks like we have the bit, but we don't want to poll it and
> >>Quanta are blocking on us working out an interface for interrupts,  
> >>as in
> >><http://dev.laptop.org/ticket/224>.  Could we get someone to own  
> >>that?
> >
> >This reminds me - I've been meaning to ask how the switches  
> >actually work.
> >There are two of them - one with the output marked PWR_BUT_in and  
> >the other
> >with the output marked EB_MODE.  I understand from the product  
> >datasheets
> >that these are Hall Effect sensors, which in effect detect the  
> >presence
> >of a magnetic field nearby.  Sensor one (PWR_BUT_in) is located on the
> >LCD side of the board at the top right near the notch.  Sensor two
> >(EB_MODE) is located on the processor side in the same location.  From
> >the position of sensor 1, I am assuming that it detects a lid  
> >opening, and
> >the magnetic field is located in the base.  I can't at all figure  
> >out where
> >the magnet is for sensor 2, nor how it detects EB mode.
> >
> >So - long story short, where the heck are the magnets? :)
> 
> When you turn the display around, wouldn't the second sensor then  
> come to rest near the same magnet? So you only need one magnet for both?

Doh - I'll bet thats it.  So the sensor doesn't really indicate orientation,
but rather that the screen is turned around.  :(  Still useful, but not
for what we wanted.

Jordan




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