Sphero bolt set_matrix_pixel error on bad pixel value

[Alex-x90]

I accidentally tried to use set_matrix_pixel on a negative pixel value, which crashes the program in the following way:

"spherov2\controls\v2.py", line 157, in new_packet
    packet = Packet(flags, did, cid, self.__seq, tid, sid, bytearray(data or []))
                                                           ^^^^^^^^^^^^^^^^^^^^^
ValueError: byte must be in range(0, 256)

While it makes sense that calling set_matrix_pixel on a negative pixel location wouldn't work, it should ideally be handled gracefully and at the very least return a specific error rather than crashing the program.

[superfashi]

The crashing of the program is a natural result of an unhandled exception, so in this case it's better to use try...catch on the user side.

[Alex-x90]

That's fine, but having a specific exception that lets you know that the issue was that the pixel coordinate was not valid (outside of the 0-7 range) rather than getting an error from an internal function with an amiguous relationship to set_matrix_pixel would be more understandable.