There was already a post about this: http://forum.tinycircuits.com/index.php?topic=1639.0 in 2016...
Basically, the demos still won't compile for M0+ (atsamd21).

Personally, I would be happy to use the "classic" tinyduino but the effective data rate when using the hardware along the lines of the provided demos is nowhere near the upperbound quoted in the documentation (256 kbps).

After all, any data transfer has to happen in blocks of (even in the original commented out version that's just 255 bytes at a time):


#ifndef RH_RF22_MAX_MESSAGE_LEN
//#define RH_RF22_MAX_MESSAGE_LEN 255
#define RH_RF22_MAX_MESSAGE_LEN 50
#endif


Without some trick for transferring data faster (is there some setting I am missing?), and given the need for a two way protocol to synchronized the data transfer I can't figure out a way to get above a couple hundred bytes per second, so I'm sure I am doing this wrong :-)