Overview

The BUZZER parameter group controls the behavior of the active piezoelectric buzzer connected to the flight controller. The buzzer provides audible feedback for system status (Arming, GPS Lock, Failsafe) and acts as a "Lost Model Alarm."

Key Concepts

1. Volume Control

BUZZER_VOLUME: Sets the PWM duty cycle for the buzzer pin.
- 100%: Full volume.
- 20%: Quiet (good for bench testing).
- 0%: Silent.

Integration Guide

Too Loud? If the startup tone is annoying during development, set BUZZER_VOLUME = 10.
Tone Control: Specific tones (Startup, Arming, Warning) are controlled by the NTF_BUZZ_ (Notify) parameters, not here.

Developer Notes

Library: AP_Notify (ToneAlarm driver).
Hardware: Requires an active buzzer (DC driven), not a passive speaker.

BUZZER_VOLUME

Buzzer volume %

Default 100

Range 0 100

Buzzer volume (BUZZER_VOLUME)

Description

The Buzzer Volume parameter adjusts the loudness of the onboard piezoelectric buzzer. This is particularly useful for reducing noise during bench testing or indoor operations ("stealth mode"), while allowing for full volume during field operations to ensure audible status alerts and lost-model location.

The Mathematics

The volume is controlled by varying the duty cycle or hardware gain of the buzzer driver, proportional to the percentage set.

$$ \text{Output Power} \propto \text{BUZZER\_VOLUME} \% $$

The Engineer's View

This parameter is part of the AP_Periph (DroneCAN Peripheral) firmware, defined in Tools/AP_Periph/Parameters.cpp. It is read by the AP_Notify library. The value is clamped between 0 and 100. On supported hardware, this adjusts the PWM duty cycle driving the buzzer; on simpler hardware (on/off only), values $< 50\%$ might silence it or have no effect, while values $\ge 50\%$ enable it.

Tuning & Behavior

Default Value: 100%
Range: 0 - 100
0: Silent.
20-50: Good for indoor bench testing.
100: Maximum volume for outdoor use.

View Source

Button Input Configuration (BTN) Camera Trigger Configuration (CAM)

MAVLink HUD

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