All-in-One module integrates the buzzer, USB port and LED indicator. This provides a cleaner installation on your drone and thus simplifies integration.
The module allows you to configure the Pixhawk via an external USB. This becomes essential when the flight controller is hidden in your drone.
The LED provides information on the state of the system via various mixtures of colors and flashes.
The buzzer is used to inform the system status, the same way as LEDs do, but with different sounds.
You can listen all tunes on this site.