Specifications

5.3.3.2 Sending files over TCP with the Ethernut
To test whether the same could happen through the Ethernut, the Ethernut was added
into the loop. The server program on the PC now sent the packet of file data to the
Ethenut first and the Ethernut inturn sent the data to the other program on the PC that
reconstructed the file. This process is shown in figure 8.
Open file
Read file data
Send packet
Process 1
Create file
Write data to
file
Receive
packet
Process 2
Read data from
sostream
Write data to
sostream
Ethernut
Figure 11 TCP file transfer with Ethernut
The Ethernut was setup having two SoStream devices. The program read a certain
amount from one SoStream that was connected to process 1 and then wrote that same
data to another SoStream that was connected process 2. The data was not put into a
cumulative buffer it was simply passed on, i.e. the data was only ever placed into a
buffer the size of the packet and then directly sent back out of the same buffer. There
was no buffer to work asynchronously between the two actions. The result of this test
was that it successfully transferred the file.
5.3.4 Storing data in a temporary buffer.
To be able to play MP3’s at least a small local buffer is going to be required. The length
of music that is produced by each byte of MP3 data is not consistent and it would be
erroneous to assume that data can be sent through a network at the same speed
constantly.
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