# USB Device Audio Speaker Project 1.4

## Purpose

This software demonstrates a basic implementation of the USB Audio class. Once connected to a computer, the evaluation kit will act as an external soundcard, playing sound through its on-board AT73C213 audio DAC.

## Hardware Requirements

The following Atmel evaluation kits are supported by this project:

- AT91SAM7SE-EK
- AT91SAM9260-EK

## Description

When plugged into a computer, the device will enumerated itself using the USB Audio class. It is configured to only act as an output (since the AT73C213 audio DAC cannot record sound), and supports hardware muting/unmuting (which it does by configuring the AT73C213 accordingly).

When plugged for the first time, an initial configuration might be necessary depending on the operating system. On Microsoft Windows, the driver will either be automatically installed, or a configuration wizard will show up; letting the wizard look for the driver itself should be enough. Once the driver is installed, the device will be automatically set as the standard output for the system.

Once the device is properly configured, sound played on the computer should be audible through the headphones jack of the evaluation kit.

## Usage

1. Build the application and download it inside the evaluation board. Please refer to the SAM-BA User Guide, the GNU-Based Software Development application note or to the IAR EWARM User Guide, depending on your chosen solution.
2. Start the application.
3. Connect the USB cable to the board. The on-board LEDs should show some activity during the enumeration process.
4. If plugging the device for the first time, some configuration may be required. On Microsoft Windows, simply tell the configuration wizard to automatically find the correct driver if it shows up.
5. Once the device is properly configured, the sound properties of the computer should indicate that the audio output is now the USB Audio device.
6. Connect a pair of headphones to the jack of the evaluation kit.
7. Any sound played on the computer can now be heared through the headphones connected to the board.

###### Atmel Corporation ©2008