Step 4: The Software
Here is the .pde sketch file.
Just download this sketch and load it into your AtMega328 chip and you are off and running!
The code has almost exhausted the RAM capacity of the ATMega328 - if you decide to make any changes, you will need to be very careful not to let the buffers corrupt the stack space.
All of the code is commented - and should be able to be followed.