Freescale Semiconductor FRDM-FXS-MULTI 데이터 시트
FXOS8700CQ
Sensors
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc.
73
10.13
Accelerometer offset correction
The 8-bit 2’s complement offset correction registers are used to remove the sensor zero g offset on the X, Y, and Z axes after
device board mount. The resolution of the offset registers is 2 mg per LSB, with an effective offset adjustment range of -256 mg
to +254 mg for each axis. The acceleration vectors represented in these registers will be added to the acceleration vectors
acquired by the ASIC from the transducer prior to being written to the output data registers (registers 0x01 through 0x06). For
example, to correct for an offset of 60 mg, a value representing -60 mg (= -60 mg / 2 mg/LSB = -30 LSB), which is 0xE2 in 8-bit
2's complement representation, should be written to the offset register.
device board mount. The resolution of the offset registers is 2 mg per LSB, with an effective offset adjustment range of -256 mg
to +254 mg for each axis. The acceleration vectors represented in these registers will be added to the acceleration vectors
acquired by the ASIC from the transducer prior to being written to the output data registers (registers 0x01 through 0x06). For
example, to correct for an offset of 60 mg, a value representing -60 mg (= -60 mg / 2 mg/LSB = -30 LSB), which is 0xE2 in 8-bit
2's complement representation, should be written to the offset register.
For more information on how to calibrate the 0 g offset, please refer to Freescale application note AN4069.
NOTE
Accelerometer offset registers can only be modified when the device is in standby mode
(See CTRL_REG1).
(See CTRL_REG1).
10.13.1 OFF_X (0x2F) register
10.13.2 OFF_Y (0x30) register
10.13.3 OFF_Z (0x31) register
Table 142. Time step for PULSE_WIND with HP_FILTER_CUTOFF[pls_hpf_en] = 0
ODR (Hz)
Max time range (s)
Time step (ms)
Normal
LPLN
High
resolution
Low power
Normal
LPLN
High
resolution
Low power
800
0.318
0.318
0.318
0.318
1.25
1.25
1.25
1.25
400
0.318
0.318
0.318
0.638
1.25
1.25
1.25
2.5
200
0.638
0.638
0.318
1.276
2.5
2.5
1.25
5
100
1.276
1.276
0.318
2.56
5
5
1.25
10
50
2.56
2.56
0.318
5.1
10
10
1.25
20
12.5
2.56
10.2
0.318
20.4
10
40
1.25
80
6.25
2.56
10.2
0.318
20.4
10
40
1.25
80
1.56
2.56
10.2
0.318
20.4
10
40
1.25
80
Table 143. OFF_X register
off_x[7:0]
0b0000_0000
Table 144. OFF_X bit description
Field
Description
off_x[7:0]
X-axis offset correction value expressed as an 8-bit 2's complement number.
Table 145. OFF_Y register
off_y[7:0]
0b0000_0000
Table 146. OFF_Y bit description
Field
Description
off_y[7:0]
Y-axis offset correction value expressed as an 8-bit 2's complement number.
Table 147. OFF_Z register
off_z[7:0]
0b0000_0000