iNavFlight
Apply custom gyro scale factor
This pr allows applying gyro scale factor in inav firmware
what is gyro scale factor error
Rotation_speed=gyro_scale_factor *gyro_raw_reading Similar to the accelerometer, gyro_scale_factor needs calibration due to manufacturing error
without calibration it will read angular speed incorrectly, which will result in AHI drift in rolls or flips, the internal state in ahrs always rotates more/less that actual rotation
You can set imu_dcm_kp = 50 to have a look on pure gyro data to see if you have this problem, This is how it looks
https://www.youtube.com/watch?v=hnNc33QCbM8
Fortunately, some gyros already have factory scale factor calibration, such as mpu6000 or icm-20689 But BMI270 do not have a factory scale factor calibration , and it seems like it has some serious errors(as high as 7deg per 360deg) without calibration,This will cause fatal AHI error just after a few rolls or flips
MoreInfo
BMI270 gyro can perform motionless SENS error compensation (CRT) and store them into Non-volatile memory, The calibrated scale factor can be applied automatically on startup. But it is kind of risky and complicate process. And i found manual applying gyro scale with this pr will achieve better accuracy
I think you have another open PR (or two?) that are similar. Does the other one supersede this one?
