Best posts made by LexJames

After some struggles, I can finally debug the firmware in Eclipse with ATMEL-ICE. Below some hints for other developers who want to debug the RepRapFirmware on Duet3 6HC.
1 - Make sure to flash a debug version of the firmware before you even try to use ICE.
2 - Install 'OpenOCD' and configure it with 'duet3_openocd.cfg' from the RepRapFirmware repository.
3 - Replace the default debugger 'dbg.exe' with 'arm-none-eabi-gdb.exe'
4 - Make sure that the lock bits of the regions 0 to 40 are cleared. If you do a firmware upgrade those bits
will be set. Use Microchip Studio (+ATMEL-ICE) to clear those bits or flash your image with Microchip
Studio.
5 - Set the compiler optimization flag to -Os. (default is -Og).
Now it should work.

Thanks for the super fast response. Next Monday I will give it a try, but also try to understand your solution. I will start simple e.g. two axis and gradually add more axes till the 5 axes + extrusion are running synchronously. I'm especially interested in your generic approach because we will add 2 more axes in future (tilt and rotation of the extruder). Wish you lots of success with your prototype.