That’s great that @sebasretes already has RAK831 working with TTN.
Actually, i’ve described how to connect RAK831 with TTN in this document:
And i’ve designed that RAK831 will generate gateway ID automatically based on eth0 MAC address every time when RAK831 power on. But it seems that there is no eth0 MAC address when people use RPi zero.
As @sebasretes said, i’ve supplied a method on RAK forum to solve this issue:
and i’m developping a new firmware v2.9.2 for RAK831/RAK2245, in the new firmware, i’ll add something to generate gateway ID automatically too, based on eth0 MAC address(normal RPi)—wlan0 MAC address(RPi zero w)—virtual usb0 address(RPi zero), so that one firmware can be used for RAK831/RAK2245 + every kind of RPi.
Just focus on this link, i’ll update v2.9.2 firmware this week: