The serial number appears to be either a 24 or a 16 bit number, but
certainly not a 32bit number. Whether it's 24 or 16 bit is hard to
tell because the data we have available always contains a zero value
in the third byte.
The communication protocol and memory layout of the Cressi Giotto
appears to be identical to that of the Leonardo. The first byte seems
to be the model number, with 0x01 for the Leonardo and 0x04 for the
Giotto.
Sometimes there are garbage bytes present after opening the serial
port, which causes the communication to fail. Flushing the buffers
after a small delay is all it takes to get rid of those bytes.
Currently, each backend has it's own function to verify whether the
object vtable pointer is the expected one. All these functions can be
removed in favor of a single isintance function in the base class,
which takes the expected vtable pointer as a parameter.
Functions which are called through the vtable, don't need to verify the
vtable pointer, and those checks are removed.
The term "backend" can be confusing because it can refer to both the
virtual function table and the device/parser backends. The use of the
term "vtable" avoids this.
This is only a preliminary version. There is certainly some room for
improvement, but the basic functionality is already in place. That
should be sufficient for daily use, and possibles issues can always be
fixed when discovered.
