the tolerance of sh200q of StickC?

[zhufu86]

I'm curious about the tolerance of the sh200q acceleration readings of StickC.
I put the StickC on the desk and make sure it will not be moved and be steady.
Then I tried the codes below but got the acceleration higher than "1g". Why is that?

>>> from hardware import sh200q
>>> import math
>>> imu = sh200q.Sh200q()
>>>
>>> for i in range(5):
...     print((imu.acceleration[0],imu.acceleration[1],imu.acceleration[2]))
...     wait(1)
...
...
...
(0.138, 0.058, 1.107)
(0.14, 0.055, 1.111)
(0.139, 0.058, 1.111)
(0.138, 0.055, 1.11)
(0.136, 0.06, 1.11)
>>> for i in range(5):
...     print(math.sqrt(imu.acceleration[0]**2+imu.acceleration[1]**2+imu.acceleration[2]**2))
...     wait(1)
...
...
...
1.11918095051694
1.12111150203715
1.12195989233127
1.12375308675883
1.11990892486845
>>>

I also tried with the configuration 16g range set. More or less the same.

>>> for i in range(5):
...     print((imu.acceleration[0],imu.acceleration[1],imu.acceleration[2]))
...     wait(1)
...
...
...
(0.137, 0.059, 1.12)
(0.137, 0.059, 1.11)
(0.142, 0.062, 1.11)
(0.139, 0.053, 1.108)
(0.128, 0.063, 1.107)
>>> 
>>> import math
>>> for i in range(5):
...     print(math.sqrt(imu.acceleration[0]**2+imu.acceleration[1]**2+imu.acceleration[2]**2))
...     wait(1)
...
...
...
1.13100221043108
1.12003080314784
1.1184927357833
1.11923321966425
1.117821094809
>>>
···

[heybin]

acceleration z is 1g, is normal

[zhufu86]

@heybin

but it is 11% more than 1g.
Is it normal? I suppose the tolerance is much lower than 10%.

[heybin]

It need calibration, maybe... i will check it

[hague]

@heybin I also found "non zero" values for acceleration and gyro. Is there a special calibration method?
Thanks....