[maemo-users] N900: Calibrating the accelerometers?

[From: Ove Kaaven]

Marcel skrev:
>> Joking aside, if it is measuring acceleration indeed it must be in another
>> unit, right?
> 
> If it's any unit at all. Maybe one could just convert it for human
> readability.

The unit is g (as in G-force). 1 G is roughly 9.8 m/s^2
(http://en.wikipedia.org/wiki/Standard_gravity)

The accelerometer's manufacturers (ST Microelectronics) may know how to
recalibrate the sensor, but they don't seem to be telling. It is
calibrated at the factory and probably requires special equipment.

I've heard some theories that differences in readings between devices
may be because the N900's assembly process might be imprecise when
installing the sensor, so that it is sometimes mounted at a slight angle
inside the device. If so, the sensor itself is not at fault.

The best you could do then is perhaps apply a configurable rotation
matrix from inside the kernel driver, but the driver does not support
such a thing yet.