# Tune Meanings (Pixhawk Series)
Pixhawk-series flight controllers use audible tones/tunes and LEDs to indicate vehicle state and events (e.g. arming success and failure, low battery warnings).
The set of standard sounds are listed below.
Note
Developers: Tunes are defined in /lib/tunes/tune_definition.desc (opens new window) and can be tested using the tune-control module.
You can search for tune use using the string TUNE_ID_name
(e.g. `TUNE_ID_PARACHUTE_RELEASE)
# Boot/Startup
These tunes are played during the boot sequence.
# Startup Tone
- microSD card successfully mounted (during boot).
# Error Tune
- Hard fault has caused a system reboot.
- System set to use PX4IO but no IO present.
- UAVCAN is enabled but driver can't start.
- SITL/HITL enabled but pwm_out_sim driver can't start.
- FMU startup failed.
# Make File System
- Formatting microSD card.
- Mounting failed (if formatting succeeds boot sequence will try to mount again).
- No microSD card.
# Format Failed
- Formatting microSD card failed (following previous attempt to mount card).
# Program PX4IO
- Starting to program PX4IO.
# Program PX4IO Success
- PX4IO programming succeeded.
# Program PX4IO Fail
- PX4IO programming failed.
- PX4IO couldn't start.
- AUX Mixer not found.
# Operational
These tones/tunes are emitted during normal operation.
# Error Tune
- RC Loss
# Notify Positive Tone
- Calibration succeeded.
- Successful mode change.
- Command accepted (e.g. from MAVLink command protocol).
- Safety switch off (vehicle can be armed).
# Notify Neutral Tone
- Mission is valid and has no warnings.
- Airspeed calibration: supply more air pressure, or calibration complete.
- Safety switch turned on/disarmed (safe to approach vehicle).
# Notify Negative Tone
- Calibration failed.
- Calibration already completed.
- Mission is invalid.
- Command denied, failed, temporarily rejected (e.g. from MAVLink command protocol).
- Arming/disarming transition denied (e.g. pre-flight checks failed, safety not disabled, system not in manual mode).
- Reject mode transition.
# Arming Warning
- Vehicle is now armed.
# Arming Failure Tune
- Arming failed
# Battery Warning Slow
- Low battery warning (failsafe).
# Battery Warning Fast
- Critical low battery warning (failsafe).
# GPS Warning Slow
# Parachute Release
- Parachute release triggered.
# Single Beep
- Magnetometer/Compass calibration: Notify user to start rotating vehicle.
# Home Set Tune
- Home position initialised (first time only).
# Power Off Tune
- Vehicle powering off.