BNO055 GYRO start problem
We use BNO055 on a custom PCB. We have several PCBs and I found that, in some of our PCBs the GYRO does not start after power on. The CALIB_STAT register shows 0 at GYRO part. When a PCB shows this phenomena that never turns on correctly (seems the BNO damaged). But, in the other PCBs it works well. We found that, it is always the GYRO sensor that sometime fails to work. Have You faced the same problem before? Any Idea?
Re: BNO055 GYRO start problem
I see here 2 issues:
1- The gyro is the only component that requires a higher voltage to work (2.5V) and draws the most current (5mA). Is your design at least 2.5V, with proper decoupling (>1uF total)?
2- The gyroscope structure is tuned to resonate at a specific frequency for proper operation. It can be damaged during manufacturing is ultrasonic cleaning, or welding is used. The vibration caused can destroy the part. Double-check the Handling and Soldering Instructions with your manufacturing process to see if all recommendations have been followed : https://ae-bst.resource.bosch.com/media/_tech/media/application_notes/BST-BNO055-HS000.pdf