@staffan Hi, Did you check the user manual file? available on download section?

If your MySensors gateway is USB, select as follows,
0_1508474313121_0d214ad7-684c-4384-86b0-053807ee98b3-image.png

Tx message processing delay: Transmission delay between on each message from MyController to this gateway to avoid the collision on MySensors network.
Driver: Keep it as Auto
Port name: default /dev/ttyUSB0
Baud rate: default 115200
Retry frequency: For some reason, if your gateway goes down. MyController attempt to reconnect every X seconds once.

Connect your gateway on RPI USB port, run this command to know your USB port name: ls -lh /dev/ttyUSB* Once you setup the gateway on MyController, your gateway should show UP. now click on Action button on gateway and select Discover, [Note: You should have added about your node data on presentation() block of your node code.]
0_1508475338692_f531a78d-46ca-4c88-8698-38bd375eecd3-image.png.

Now you can see your gateway and nodes on MyController.