Accelerometer problem (HW or SW)?

[soeiro]

N900

I've noticed a weird behavior from the N900 accelerometer. It sometimes get stuck in one or more axis. I've noticed this in some applications (Photo, Bounce, Phone, Attitude, etc). To make sure I've installed the AccDisplay application (it shows the current X,Y and Z) values.

The problem pattern is approximately this:


After some time, one or more axis get stuck;
If you reboot the device, the axis get stuck in some number close to zero (I'm not sure if this happens always"), but different from the previous stuck values;
If you use the device until it the battery is depleted and it shuts down and then you turn it on only when it has recharged completely (green light), the accelerometer starts to work again (nothing stuck);
If you shut it down AND remove the battery, when it get on again the accelerometer seems to work (I've tested this only once);


So, do you guys have seen this behavior? Do you think it is a software problem (that hopefully can be fixed) or defective hardware?

Thanks

[ndi]

Acceleros are typically unpowered so they shouldn't care of reboots, might be software, However, software doesn't just lock for no reason, we all have it, so I'm guessing combo (Software re-sets all calibration on reboot).

Best guess is the accelero feeds the software some odd value, like 50.000.000 and the axis get re-scaled for those values, since if it goes to 11 then 11 is the new 10. This would explain why the normal range is close to zero and unresponsive.

It is unlikely this is software alone. I would clean-flash the device to be sure, then just install AccDisplay and see how it goes. If it's still stuck, RMA?

[juahan]

There have been discussion about this earlier too. I have had the accelerometer stuck once, fixed it taking of the battery for a while as was recommended in one earlier topic on this.

http://talk.maemo.org/showthread.php?t=38644
http://talk.maemo.org/showthread.php?t=38965
http://talk.maemo.org/showthread.php?t=37649
http://talk.maemo.org/showthread.php?t=36218

https://bugs.maemo.org/show_bug.cgi?id=6996

[mattaustin]

Since the update my accelerometer has gotten stuck about 5 times. Rebooting fixes it. Today I had the portrait mode bug on 3 separate occasions (entire phone gets stuck in portrait mode) - am pretty sure this was a side effect of the stuck accelerometer. Again a reboot fixed - haven't had to remove the battery yet.

[ndi]

How would a stuck accelerometer freeze the phone in portrait? Having a stuck acc is basically the same as holding the phone one way. Exiting Phone app or keyboard out in browser should return to landscape ignoring acc feed.

Must be software glitch?