Can I disable the D13 Led function with arg in the makefile, or do i have to change the makefile
If you've downloaded the latest source code (5.0) from Google Code Archive - Long-term storage for Google Code Project Hosting. (using mercurial), you should be able to do it from the command line with omake atmega328 LED_START_FLASHES=0
If you have older source, you'll need to modify the makefiles. (but also be aware of Google Code Archive - Long-term storage for Google Code Project Hosting. )