We received a report of a Darwin Air device which has a very high error
rate. The majority of the echo packets is incorrect, but since this
doesn't seem to have any effect on the actual data packet, we can just
ignore this error. If there happens to be a more serious error, it will
be detect in the data packet.
Sometimes there were also a some garbage bytes received at startup.
Adding a small delay seems to fix this.
When trying to send the commands as fast as possible, without any delay,
the failure rate is very high. Almost every single packet fails with a
timeout at first. Retrying the packet works, but those many timeouts
make the download extremely slow. Adding a small delay avoids the much
more expensive timeout and speeds up the transfer significantly.
