We currently have issues in our board with the ADXL362. In some cases we read 0 or 255 from all registers and in some cases we read values as expected. It is randomly.
We follow the design guides from your datasheet. My initial question is:
In the datasheet it says:
"...The ADXL362 does not require any particular startup transient characteristics, except that it must always be started up from 0 V. When the device is in operation, any time power is removed from the ADXL362, or falls below the operating voltage range, the supplies (VS, VDD I/O, and any bypass capacitors) must be discharged completely before power is reapplied. To enable supply discharge, it is recommended to power the device from a microcontroller GPIO, connect a shutdown discharge switch to the supply (Figure 47), or use a voltage regulator with a shutdown discharge feature, such as the ADP160."
If we don't start from 0V, can this explain the issue we see?