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MP3 Audio

The MP3 Audio plugin is a fully featured MP3 decoder with direct amplified audio outputs suitable for connecting directly to headphones or speakers via an amplifier. The plugin is based on the VLSI Solutions VS1011 chip - an MP3 decoder with SPI interface.

Completed MP3 plugin, plugged into a Lettuce-v1 core board.

Description [size] Format
Circuit schematic [8.4KB] Adobe Acrobat PDF
PCB layout [65.9KB] Adobe Acrobat PDF


The plugin is designed to interface with the Lettuce-v1 core board via an SPI+DIG header.

Audio out header

The format of this header is similar to the standard 4 pin CD Audio connector found on CD ROM drives.

The audio out connector is implemented as follows:

Pin Name Purpose
1 LEFT Audio output - left channel
2 Gnd Ground
3 Gnd Ground
4 RIGHT Audio output - right channel

Component list

Below is a full list of components required to build the mp3 plugin board.


ID Value Package Description
U1 VS1011E SO28 MP3 Codec


ID Type Description
J1 2x4 100mil R/A socket Core SPI socket
J2 2x4 100mil R/A socket Core DIG socket
J3 1x4 100mil header Audio output


ID Value Package Description
R1 ? 0805 Plugin SPI ID
R2 100K 0805 XRESET clamp
R3 1M 0805 Across xtal
R4 100K 0805 GPIO clamp
R5 100K 0805 GPIO clamp
R6 100K 0805 GPIO clamp
R7 100K 0805 GPIO clamp
R8 10R 0805 Audio output
R9 10R 0805 Audio output


ID Value Package Description
C1 33pF 0805 Oscillator
C2 33pF 0805 Oscillator
C3 100uF 100mil radial Audio output
C4 100uF 100mil radial Audio output
C5 100nF 0805 RCAP


ID Value Package Description
X1 12.288MHz HC-49* Oscillator crystal

* = U4 or any other 200mil pitch crystal type also suitable.

Updated on 2010-04-25 13:41:34 +0000 | Requested on 2022-12-02 15:45:59 +0000