Thanks for the report.

The PORTB register is specific to ATMega 8/168/328 Chips as shown in the Arduino Port Register documentation.  The Zero has a different set of registers which are 32bit instead of 8 bit.

Manipulation of the regsiters and timer vectors is low level so often becomes specific to a certain family or range of chips, and normally this is avoided by using the Arduino functions for digitalRead/Write or by using some of the libraries available which handle this element for you , such as digitalWriteFast is available for the Arduino Zero.

Hopefully this helps work towards converting your code for the Zero, or making it compatible with both family of chips using #ifdef statements to differentiate between the board in use.

I suspect the port is not available when the Serial is being used. If the IDE set to "Debug" then the serial debugger will have been activated automatically on that port (that is the default setting).

If you switch the tool bar from Debug to Release and try compile does that work?


The yellow area at the top of this page is important when creating threads in this forum. It shows many useful configuration and build properties making it easier for us to provide support.