The level trim was saved, or an AutoTrim ended
What ArduPilot says:
- Trim saved
- Must be flying to use AUTOTRIM
- AutoTrim: Trims saved
- AutoTrim cancelled
The level trim (AHRS_TRIM_X, AHRS_TRIM_Y) tells ArduPilot which attitude is “level”, so the copter does not drift in Stabilize with the sticks centred. “Trim saved”: the Save Trim switch (RCn_OPTION 5) added the present roll and pitch stick positions to it; this works in Stabilize or Acro with the throttle at zero. “AutoTrim: Trims saved”: AutoTrim, started by holding the yaw stick right for 10 s after arming in Stabilize, ran its 25 s in flight and saved the result. “AutoTrim cancelled”: the copter left Stabilize, landed or was disarmed before the 25 s were up.
Trim in still air. A copter that drifts in wind is not out of trim, and a drift in Loiter is a matter of position, not of level. Large trim values (more than a few degrees) point to a flight controller that is not mounted level or to a poor accelerometer calibration.
Parameters to look at
| Parameter | What it is |
|---|---|
AHRS_TRIM_X | AHRS Trim Roll |
AHRS_TRIM_Y | AHRS Trim Pitch |
Where to do it:Setup & Tuning Guide
The code that sends it
Trim saved
ArduCopter/RC_Channel.cpp Copter::save_trim() · Open in ArduPilot Copter-4.6.3
ArduCopter/RC_Channel_Copter.cpp RC_Channels_Copter::save_trim() · Open in ArduPilot Copter-4.7.1
Must be flying to use AUTOTRIM
ArduCopter/RC_Channel_Copter.cpp RC_Channels_Copter::auto_trim_run() · Open in ArduPilot Copter-4.7.1
AutoTrim: Trims saved
ArduCopter/RC_Channel.cpp Copter::auto_trim() · Open in ArduPilot Copter-4.6.3
AutoTrim cancelled
ArduCopter/RC_Channel.cpp Copter::auto_trim_cancel() · Open in ArduPilot Copter-4.6.3
ArduCopter/RC_Channel_Copter.cpp RC_Channels_Copter::auto_trim_cancel() · Open in ArduPilot Copter-4.7.1