[Hdaps-devel] Re: [ltp] IBM HDAPS Someone interested? (Userspace accelerometer viewer)

[Dave Hansen]

On Mon, 2005-07-11 at 10:42 +0100, Paul Sladen wrote:
> The sensor gives us two 10-bit AD values (corresponding to 0..1 volts on the
> ADI chip), temperature (Celsius) and three status bits indicating:
> 
>   * lid open/closed

Which bit did you find this in?  I haven't tried with the lid closed.

>   * keyboard activity
>   * nipple movement

Technically, it's mouse movement :)  I think it gets set on my T41p when
I'm using the touchpad.

> On the X40 I borrowed (thanks Robert McQueen), at rest the outputs hover
> around 512 (0x200).  Gravity is supposed to fall off in a sine-wave during
> rotation, but I found that:
> 
>   theta = (N - 512) * 0.5
> 
> provides a surprisingly good approximation for pitch/roll values in degrees
> in the range (-90..+90) so I think the sensor can do ~= +/-2.5G .

Interesting.  

-- Dave