Auto-baudrate is unreliable

[Williangalvani]

It seems that we need a long (1ms?) pause after send_break().

this results in no response from the ping:

this results in a response:

[patrickelectric]

as reference: https://github.com/bluerobotics/ping-cpp/blob/master/src/hal/link/desktop/serial-link.cpp#L41

[Williangalvani]

also, thanks @RaulTrombin for noticing the different in the pause there =]