Unusual Spikes in BMI270 Breakout

Sensors IMU & Motion
1

Hi all,

I’m working on a project using the SparkFun BMI270 IMU and I’m seeing some unusual behavior. I’m trying to perform an Allan Variance analysis to characterize the sensor’s noise, which requires long data recordings.

I’ve configured the IMU as follows:

  • Mode: Performance

  • Accelerometer Range: ±4g

  • Gyroscope Range: ±2000 deg/s

  • Sample Rate: 400 Hz for both accelerometer and gyroscope

During my data recording sessions (each lasting over 3 hours), I’ve noticed frequent, large spikes in the data from the accelerometer. These spikes seem to appear randomly on different axes. I’ve attached two images showing this issue. The first shows significant spikes in the accelerometer’s Z-axis, while the second shows the same behavior in the Y-axis.

I’ve taken great care to minimize environmental vibrations during the recording. I’m wondering if this behavior is typical or if it points to a potential issue with my setup or the sensor itself. Any insights would be greatly appreciated.

Many thanks

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2

Hi @BH199 ,

Are the spikes a single large reading? Or is the peak of each spike surrounded by a few lesser, but also large readings?

If these are single sample / value events, they could be due to bit errors in the I2C data. Check your I2C cable, keep it as short as possible. Check you only have one pair of pull-up resistors connected on the I2C bus.

I hope this helps,
Paul