I'm trying to use Nidaq 6323 to read the acceleration data from ADXL358. Since Nidaq directly reads analog signal as voltage, I'm facinf issues with interfacing the accelerometer with the daq. I notice that when I divide the measured voltage with the sensitivity then all the three axes are reporting ~11 (Raw_voltage/sensitivity: 1V/0.08=10g?). Even when I place the accelerometer on a flat surface I get the same reading.
(Note: I have set the range as +/- 10g, put both the ST1 and ST2 pins to low and STBY to high)
First of all I would suggest to crosscheck the supply setup; this a ratiometric device to V1P8ANA, how is the sensor supplied? Is the ADC properly referenced to V1P8ANA? Is the power sequenced as shown on page 12 of the ADXL358 datasheet?
Also note that the 0g offset is expected to be
\frac{V_{1P8ANA}}{2}=0.9\text{ V}
in addition to the 0g error of 125mg.
That being said to properly interpretate that ~11 measurement take in to account the sensibility (1/0.08 =12.5g) and substract the 0g errors mentioned above.
An example with a properly tuned supply under normal conditions and ignoring ADC accuracy details :
A 1.2 V raw measurement from the ADC would be translated as follows:
