Specifications

To achieve the above specifications the product was broken up into the components
shown in figure 5.
Central
Processing
Play List
Management
File transferring
Buffer
Management
TCP/IP
c apabilities
Interaction with
windows file
system
Graphical user
interfac e
User c ontrols
MP3
decoding
Line out level
CD quality audio
Figure 5 Overall design layout
An embedded solution needs to be achieved that has TCP/IP capabilities and can
interact with the Windows file system through the TCP. The TCP system must be able
to transfer at least 30Kbytes/sec. This was determined by playing a 192Kbbs MP3 file
remotely on the computer using Winamp and monitoring the network traffic through the
Windows XP task manager. A central processor must be able to run this TCP software
as well as manage the play list formation, file transferring and local buffers of data. It
was decided that approximately 2 seconds of audio buffer would be all that is needed to
allow for network speed deviations. This equates to about 25Kbytes of RAM. The
device will need to be able to take the data received from Windows and decode the data
into CD quality audio at a line out level. A user interface must be present to display the
song that is being played and enable the user to construct a play list. Ideally, all of this
user interface will be implemented on the device itself making it possible for
autonomous operation. The user will be provided with buttons to control all the required
actions of the player.
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