Freescale Semiconductor FRDM-FXS-MULTI 데이터 시트
FXOS8700CQ
Sensors
78
Freescale Semiconductor, Inc.
10.15
Magnetometer offset correction
10.15.1 M_OFF_X_MSB (0x3F), M_OFF_X_LSB (0x40), M_OFF_Y_MSB (0x41), M_OFF_Y_LSB
(0x42), M_OFF_Z_MSB (0x43), M_OFF_Z_LSB (0x44) registers
The zero-field output for each axis can be adjusted by writing to these registers. The user must set M_CTRL_REG3[m_raw] =
0 (default) for the values in these registers to have any effect on the magnetic output data.
0 (default) for the values in these registers to have any effect on the magnetic output data.
Desired offset should to be written into the 15 most-significant bits in each register pair using 2's complement representation. The
offset registers have a sensitivity of 0.1
offset registers have a sensitivity of 0.1
μT/LSB and with an effective offset adjustment range of -1638.4 μT to +1638.3 μT.
The magnetic field vectors represented in these registers will be subtracted from the magnetic field vectors acquired by the ASIC
from the transducer prior to being written to the output data registers (registers 0x33 through 0x38). For example, to correct for
an offset of 60
from the transducer prior to being written to the output data registers (registers 0x33 through 0x38). For example, to correct for
an offset of 60
μT, a value representing 60 μT (= 60 μT / 0.1 μT/LSB = 600 LSB), which is 0x0258 in 15-bit two's complement
representation, should be written to the offset registers following a left-shift for proper alignment (0x0258<<1 = 0x04b0).
Table 175. M_OFF_X_MSB register
m_off_x[14:7]
0b0000_0000
Table 176. M_OFF_X_LSB register
m_off_x[6:0]
—
0b000_0000
0
Table 177. M_OFF_Y_MSB register
m_off_y[14:7]
0b0000_0000
Table 178. M_OFF_Y_LSB register
m_off_y[6:0]
—
0b000_0000
0
Table 179. M_OFF_Z_MSB register
m_off_z[14:7]
0b0000_0000
Table 180. M_OFF_Z_LSB register
m_off_z[6:0]
—
0b000_0000
0