Sudden Motion Sensor working strange in Unibody!

[akcasoy]

Hi guys!

I got a macbook pro 15 recently and i was trying out the applications on the Net. I tried smacbook which works with the sudden motion sensor of the hard disk...
Also i tried liquidMac app.. But what i realised is, they both didnt work for me well..
when i lay down macbook through left side, the liquid must go to left for example, but nothing happens, actually when i move laptop through forward or backward they are moving.. It is like the hard disk was horizontal before and my disk is like vertical??? Do you have any idea??

 

[gr8tfly]

I don't think those apps have been updated in a long time. The newer (and Intel) machines have a different sensitivity and, I believe, sense. I don't think it indicates there's a problem.

Try "SeisMac" - it should show you correct data (looks like this is even a couple years old, but functions correctly)

 

[akcasoy]

But as i heard, other people who are using the same machine (macbook unibody) do not have this problem.

 

[gr8tfly]

But as i heard, other people who are using the same machine (macbook unibody) do not have this problem.

Hadn't read anything about that.

For reference (on my 17" ubMBP):

X-axis positive is left up, right down (clockwise rotation)
Y-axis positive is front up, rear down
Z-axis >1G is lifting (as you'd expect)

SeisMac also has graphics which show which way is positive/increasing for each axis.

Just fyi - the sensor is not in the hard drive. It's built into the MacBook. There might also be a drop sensor in a particular drive, but it's independent of the MacBook and OS-X.

 

[akcasoy]

Mine is like this

Y-axis positive is left up, right down (clockwise rotation)
X-axis positive is front up, rear down

And suggestions?? Can it be broken or sth?
OR is there any way to play with this directions?

 

[gr8tfly]

Mine is like this

Y-axis positive is left up, right down (clockwise rotation)
X-axis positive is front up, rear down

And suggestions?? Can it be broken or sth?
OR is there any way to play with this directions?

So the X and Y axis are swapped. I don't know of a specific remedy - I suppose it could be some kind of manufacturing defect, but I can't imagine what. AFAIK, it's a single device. It could simply be the way this particular model MacBook is designed. The applications (including SeisMac) make certain assumptions about the machine(s), but there isn't a published API for the SMS (unless that's changed very recently).

You could try resetting the SMC, but otherwise, I don't have any other thoughts. Functionally, it doesn't really matter, since the system would be looking for rapid changes in acceleration to determine if/when to park the hard drive heads. It's certainly a strange anomaly, though.