Switch to indicate ebook mode

[Bert Freudenberg]

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?

- Bert -