I tried to output the acceleration data of the accelerometer, but I found on X, Y, Z directions, the maxium value is not 9.8 m/s^2 and the minum value is not -9.8 m/s^2.
When the Z1 screen is face up, the maximum Z value is around 8.8.
When the screen is face down, the minum Z value is around -10.5
Samely, the maximum Y value is around 10.2.
the minum Y value is around -9.6.
The maxium X value is around 9.5,
The minum X value is around -9.9.
To compensate the error, adjust the origin point may can work. For example, the origin value at a certain axis could be (maxium+minum)/2.
So for my data, the X origin could be adjusted to (9.5-9.9)/2 = -0.2. The Y origin could be adjusted to (10.2-9.6)/2 = 0.3. The Z origin could be adjusted to (8.8-10.5)/2 = -0.85.
What's your experience to compensate the accelerometer errors?