1wire on RockPiS

Hey there,
I’m trying to use a 1wire temperature sensor with my RockPiS. It’s a DS18B20.
I’ve enabled 1wire by adding ds2490 to /etc/modules.
However, my sensor doesn’t get recognized, I believe I got the pinout wrong.

Power is connected to +3.3V (H1-1) and GND (H1-9), the data pin is connected to GPIO2_A4 (H1-7).
I’m using a 4.7kΩ-Resistor connected to the data & 3.3V-Pin. This setup has worked flawlessly with a RaspberryPi, however not with the RockPiS.
Is GPIO2_A4 the wrong pin? Did I forgot configuring something?

Edit: I’m using the Ubuntu 18.04 image, btw.