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For example, if the sensor has P_AVE[7..0] set to 2 and T_AVE[7..0] set to 1 and it is
required to reduce the RMS amplitude of the pressure reading noise by a factor of 4
and the temperature reading noise by a factor of 2, then using Figure 8, the new
values for P_AVE[7..0] and T_AVE[7..0] will be 6 and 3 respectively.
i.
Unlock the configuration data registers as described in section 4.4.1.
ii.
Update the number of pressure samples.
Write 6 to AVERAGE: P_AVE [7..0] <82 [15..8]>
iii.
Update the number of temperature samples.
Write 3 to AVERAGE: T_AVE [7..0] <82 [7..0]>
iv.
Save the new sample values to non-volatile memory if required and re-lock
the configuration data registers as described in section 4.4.1.
As a result of the above changes, the sensor acquisition time will typically increase
from 23 ms to 163 ms.
If the sensor automatic update mode is used (see section 4.3.2), ensure the auto-
update period (see section 4.4.3) is set to be longer than the modified acquisition
time.
Failure to observe this precaution will result in the queue error flag
(STATUS: QERR <0 [10]>) being set and may result in invalid pressure and
temperature data.
4.4.7
Maximising the update rate
For applications that require the DPS 5000 sensor acquisition time to be faster than
is achievable by adjusting the sensor SNR (see section 4.4.6), the sensor provides an
interleave mode. This mode is only intended to be used when both the P_AVE[7..0]
and T_AVE[7..0] bit fields of the AVERAGE register are set to 0 and should be used
with caution. It provides a sensor acquisition time of typically 10 ms permitting a
pressure and temperature measurement refresh rate of up to 100 Hz to be
achieved.
To use the interleave mode:
i.
Set the P_AVE[7..0] and T_AVE[7..0] bit fields of the AVERAGE register to 0 using
the steps described in section 4.4.6.
ii.
Set the interleave mode bit.
Write 0b1 to STATUS: INTRDG <0: [9]>
4.4.8
Pressure re-calibration
The user may perform a 2 point pressure re-calibration on the DPS 5000 sensors by
adjusting the zero and span settings of the sensor. The following steps describe the
procedure:
i.
Apply a known pressure, P
and record the measured pressure, P
P
= Read COMP_PRES: COMP_PRES [31..0] <1 [31..0]>
M1
12
To minimise the effects of noise it is recommended that the values P
of several measurements.
26
CAUTION
, ideally ≤ 10% of the sensor's full scale pressure,
A1
12
.
M1
and P
M1
May 2015
used are the average
M2
K0582 Revision B
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