-my $device = $ENV{DEVICE} || '/dev/ttyUSB2'; # last device! control port!
+my $device = shift @ARGV || $ENV{DEVICE} || '/dev/ttyUSB2'; # last device! control port!
my $port = Device::SerialPort->new( $device ) || die "$device: $!";
$port->baudrate(115200) || die "fail $device baudrate";