About Vincent

Vincent

This means you either write some wrong value into sensor register or overwrite the sensor register. So you need to check if you follow correct procedure and write proper value into it.

Vincent

The correct procedure for put sensor in suspend mode is: NDOF -> Config mode -> Power Suspend mode. The correct procedure for wake up sensor under suspend mode is: Power Suspend mode -> Config mode -> NDoF mode. When sensor change to suspend mode, the register content will keep, so after resume, the offset value is still in the registers and system calibration level will keep the same value as previously enter the suspend mode. Sensor output will also keep as previous value. After Sensor reset, all vlaue in registers will be lost. Then system calibration will be 0 as well as all sensor calibration level. System starts from initlia status. If all sensor are fully calibrated, the system calibration status should also 3. If not, we need to take a close look what happened then.

Vincent

Yes, from the feature setting, BMI270 provide all wrist interrupt features. But in sensor parameter, BMI270 as our latest IMU provide high accelration parameters and also improved gyro parameters. and overall power consumption is only 685uA for full operation mode (A+G). This means in TWS general use case, BMI270 can also fit into. In the other hand, we can also recommend BMA456 with triple tap for TWS use case. Both TWS use case are not considering the high bandwidth for bone detection.

Vincent

Did you mean your FIFO content like following: 0x9E 0x00 0x00 0x00 0x00 0x00 0x00 0x9E 0x00 0x00 0x00 0x00 0x00 0x00 ........ If it is the case, then sensor is not working correctly. Please share your sensor settings including the FIFO setings here? (better to have a register dump of all register value)

Vincent

When we convert the register value to physical result, we expect the output is linear. Take example: the corolation between physical acceleration and the MEMS output is treat as linear. Then we apply 1 g on sensor, sensor output is also 1g. And this sensitivity efficient is identical in full range. This "non-linear" parameter indicate that the mapping of physical value as sensor output is not exactly fully linear. so the sensitivity values might different in some point of accelration value within the range. (just for example of explain: 0.5g physical accleration might output as 0.6g) So when you estimate the sensor output error, you need to consider this non linearity error inside.

Bosch Shared

Re: Wakeup BNO055 from suspend mode

Re: Wakeup BNO055 from suspend mode

Re: IMU for TWS

Re: Reading only the header from FIFO (BMA400)

Re: Meaning of non-linearity in datasheet?

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