Compact USB Audio Card with ATmega162L-8PI

The project aims to create a high-speed USB audio/sound card based on ATmega162L-8PI microcontroller that belongs to PCI device in most computers.

This audio device can be easily connected with computer using a USB B-type to A-type cable. The card contains 3 interfaces, a reset key, and an indicator LED. The interface includes a RS232 for debugging, a USB B-Port for transferring data between the computer and audio card, and a 3.5mm audio connector for connecting earphone or speaker. A USB1.1 is also featured by this USB audio card. It can be changed to USB2.0 interface chip since the chip is just a transceiver.

The USB protocol is mainly processed by the central processor ATmega162L as well as the transfer of data between USB module and audio codec module. The card has a 16-bit parallel to serial converter and a CPLD frequency divider that generates the syn clk and bit clock while receiving 16 bits parallel data from ATmega162 and transmitting serial data to audio codec.

The audio from PCM3000E is received by a dual audio power amplifier TDA2822 which will drive the speaker or earphone. The USB port provides the power.

Rest of the project