First try debugging your code ...
debug steps

first send a char
next receive a char to led or something.
next send 'received char+1'. INC loop.
next build buffer to receive data.
fill buffer and send when buffer is full.
next build receive buffer..
then send test chars to check code of buffer.
next combine both buffers with overhead (tasks) code.

then continue working on other drivers or tasks.


have fun.

coding one step a time, saves you time in debugging AND FIELD UPDATES ...

you could also use a simulator to see what your code is doing!!!

bert