I've been working in my spare time during October to link the SAM3X8E hardware to the existing ECUHost OS. The good news is that coding peripheral modules for SAM3X8E is mostly taken care of by the excellent ATMEL ASF software framework.

So progress has been pretty good, with digital I/O, analog inputs and timed inputs mostly done (as far as the test engine needs anyway). Next step is to get the timed outputs working for fuel injection and spark timing! I am hoping to get enough of the ECUHost OS working with the SAM3X8E that I can run the engine by the end of November.

There haven't been too many changes needed to the OS, interrupts and service calls between the NXP Kinetis (first implementation) and the SAM3X8E - there doesn't seem a lot of difference between Cortex M3 and Cortex M4 from the programmers point of view.

I think these ARM micros are are great basis for a programmable after-market or hobbyist engine management system!