I'm working with mpu9250 gyroscope and I got fine measurements for beginning period (few minutes). I calculated offset at start in manner to average sum of first 1000 results from mpu9250 gyro. But If I put mpu9250 on one place and I don't move it I got accumulated error of axes. For example after 5min I got offset of pitch ~1.2degree, roll ~2.5degree and yaw ~1degree.
Does anyone have idea how to solve this or what is there happening? I assume that mpu9250 need some movement each period (for example mpu9250 need position change every 10sec to avoid accumulating of error)