Analog Devices ADXL345 - Manual (Page 10)

UG-015 Evaluation Board User Guide
Rev. 0 | Page 10 of 12
TEMPERATURE TAB
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The Temperature tab is used to examine the performance of
the ADXL345 over temperature. By plotting the acceleration vs.
temperature while the ADXL345 is not experiencing dynamic
acceleration, the offset temperature coefficient can be determined
by taking the slope of the best-fit line to the acceleration vs.
temperature data. The inertial sensor evaluation system assists
in the accuracy of this measurement by putting the accelerometer
on a separate satellite. Only the satellite has to be placed in an
environmental chamber, which eliminates inaccuracies due to
the temperature effects of voltage sources, converters, and other
biasing circuits.
The Temperature tab, shown in Figure 15, allows a maximum
number of points to be set and at what rate data is acquired. The
testing can be stopped before reaching the maximum number of
points. The data rate for the accelerometer can also be set to ensure
that the testing is performed under conditions most like those
that the part would be configured for in a system.
Figure 15. Temperature Tab
The data in the top graph in Figure 15 is used for determining
the offset temperature coefficient. The bottom graph displays
the temperature over time. To save data, a measurement cannot
be in progress. When the measurement ends or is stopped, click
the Save Data button to save the data to a .txt file.
After selecting the values in the Sample Points, Time Interval [s],
and Data Rate [Hz] boxes, data acquisition begins by clicking
the Start Meas button. When testing is in progress, the Meas.
In Progress
indicator lights up. To end the test before the
maximum number of points, click the Stop Meas button.