Sensors Status Registers; Imu383 Spi Register Write Methodology - Aceinna IMU383 Series User Manual

IMU383 Series User's Manual
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Sensors status registers

For the IMU383, triple sensor redundancy (along each axis) has been introduced. Each axes of
every sensor is individually calibrated. The output signal generated for each sensor type is a
composite of the three unique sensors. For example, output value for acceleration on axis X in
normal conditions is combination of all three individual X-axis accelerometer readings.
The output from each sensor is constantly monitored and, if an anomaly is detected, the failing
sensor is removed from the triad. This is done on a sensor-type basis. For example, if a failure of
an accelerometer is detected, all three axes from that accelerometer will be disabled and the
resulting acceleration output will consist of the combined signal from the two remaining good
accelerometers. However, the angular-rate output will be a combination of all three rate-sensors.
Additional sensor status registers contain more detailed information about sensors status for each
redundant sensor chip (read-only):
Sensor SPI Register Bit 0 (0x01)
Chip #
1 0x1D AccelX
2 0x1E AccelX
3 0x1F AccelX
If a specific bit is HIGH – that sensor axis is considered faulty and excluded from the output.

IMU383 SPI Register Write Methodology

The SPI master configures the unit by writing to specific registers. However, unlike reads, writes
are performed one byte at a time. The specific registers that affect system configuration are listed
in Table 13 along with their write-addresses.
Name
DATA_READY
OUTPUT_DATA_RATE
RS_DYNAMIC_RANGE
LOW_PASS_FILTER
ORIENTATION_MSB
ORIENTATION_LSB
The following example highlights how write-commands are formed in order to initiate a sensor
self-test:
·
Select the write address of the desired register, e.g. 0x34 for data ready options
·
Change the most-significant bit of the address to 1 (the write-bit), e.g. 0x34 becomes
0xB4
·
Create the write command by appending the write-bit/address combination with the value
to be written to the register, e.g. 0xB404 (see Table 14 for a description of the self-test
register)
Doc# 7430-1398-01
Table 12 Sensors Status Registers
Bit 1 (0x02) Bit 2(0x04)
AccelY AccelZ
AccelY AccelZ
AccelY AccelZ
Table 13 IMU383 Configuration Registers
Write Address Function
0x34 See Table 14
0x37 See Table 15: Sets Output Data Rate (ODR) of the unit
0x39
See Table 16.: Set the rate-sensor dynamic range and the
digital filter
0x38
0x74
See Sections 4.8.4and 7.4: Sets the orientation (x, y, and z-
axes) of the unit
0x75
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Bit 3(0x08) Bit 4 Bit 5(0x0020)
(0x0010)
RateX RateY RateZ
RateX RateY RateZ
RateX RateY RateZ
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