PNI SENtral - Manual (Page 48)

PNI Sensor Corporation Doc #1018049 R03
SENtral Technical Data Sheet Page 47
parameters associated with SENtral’s continuous background calibration function and
gyro bias correction. When SENtral is powered down or otherwise re-initialized,
these parameters also are re-initialized and the parameter refinement process must
start over. The parameter transfer process provides the ability to save these
parameters to the host as they are refined, and to reload them if the parameters within
SENtral are re-initialized. Thus, if the WarmStart parameters periodically are
retrieved from SENtral and saved by the host, it is possible to effectively warm-start
SENtral after it is re-initialized by reloading the WarmStart parameters into SENtral
that previously were saved to the host.
To effectively enable a warm-start process, it is necessary to periodically save all 35
WarmStart parameters, and to reload all of them after SENtral is re-initialized.
SensorRange
The dynamic ranges of the sensors used in conjunction with SENtral normally are set
as part of the Configuration File. Typically the gyroscope will be set to 2000 dps, the
accelerometer to ±2 g or ±4 g, and the magnetometer to ±1

T. However, there may
be instances when it is desirable to change the dynamic range. For instance, if
SENtral will be used in an application with frequent shock, such as jogging, it may be
necessary to increase the accelerometer range to something greater than ±4 g.
SensorRange[mag:accel] loads or retrieves the magnetometer range data in
ParamByte0 and ParamByte1, while the accelerometer range data is in ParamByte2
and ParamByte3. For example, a likely readout for SensorRange[mag:accel] in the
4x RetrieveParamByte registers is 0xE8030200, corresponding to a magnetometer
dynamic range of 0x03E8 (±1000

T) and an accelerometer dynamic range of
0x0002 (±2 g). SensorRange[gyro] loads or retrieves the gyroscope range in
ParamByte0 and ParamByte1, while ParamByte2 and ParamByte3 are reserved and
should be 0x00.
DriverID and AlgorithmID
Sensor driver and algorithm revision information can be retrieved using the Parameter
Transfer process. Table A3-3 indicates how these parameters are defined.
ParameterBytes 2 and 3 for Parameter Numbers 78 and 80 are 0x00 and reserved for
future use.