# 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 and can be tested using the tune_control module.

# 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 {#error_tune_operational}

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.