I made a pull request over on github, if @martinhjelmare accepts it we should be good to go.

Well... I think I fixed it, let's hear it for documentation. Just when I had MQTT setup half way I got struck by the idea that there was some group flag for configure. And indeed there is, setting --my-serial-groupname=nodered did the trick making /dev/pts/X owned by group nodered and let Node-RED connect to it, writing and reading works just fine now.

Thanks @gohan for your input I think I would have gone the ethernet route in the end if this last test had failed.

@inso Did you sudo make install after building it? This command copies the service file and mysgw to their respective locations.