Bidirectional DShot (RPM telemetry)
Bidirectional DShot lets the ESCs report each motor's actual RPM back to the flight controller — the foundation for the RPM filter and dynamic idle.
Without this RPM data there is no RPM filter. Faulty or missing RPM telemetry weakens motor-noise filtering. PIDoctor detects whether the RPM filter (and therefore the telemetry) is active and effective.