Support for Portenta board

[prdipalma86]

First of all, I must say that it is a joy to use your library.
Please add support of your library to Arduino portenta C33.

[SRGDamia1]

I'm not familiar with that board, but this library isn't board-specific. It should work with anything that implements an Arduino Stream class.

[prdipalma86]

Thanks Sara, but I'm still having problems with CRC uncorrect response. I was wondering if the Renesas architetture is not compatible with this library.
Paolo