IMU order and related

ArduCopter Copter 4.0
1

@tridge A question about the IMU order on FC’s with multiple IMU’s. For example the CUAV Nora shows on the HW ID screen as order:
Primary-ICM20689
Secondary-BMI088
Tertiary-ICM20649

Why wouldn’t we want the BMI088 as the primary I’m wondering? Or is this not significant? And another point about fast sampling. The ICM’s are fast sampled by default (from hwdef) and the BMI088 is not. Why is this?

1 Like
2

The BMI088 is read at its maximum sample rate (2KHz) so fast sampling doesn’t apply. It’s only the ICM parts that allow much higher sample rates.

1 Like
3

Got it, thanks Andy! Is this also the reason the ICM is primary?

4

No idea. My guess is it’s because its the IMU we have the most experience with so maybe the “safest”.