GoPiGo Prototyping Pins

I am newbie, and therefore my question is may very obvious. I have tried to install sensors like a magnetometer ( to the prototyping pins on the GoPiGo but I don’t get a signal. However, if I plug the sensors directly on the Raspberry Pi everything works just fine. Therefore, I wanted to ask how can I get the data of the sensor from the GoPiGo?

What pins does the magnetometer use to communicate?

I see, this is an i2c sensor. Have you tried connecting VCC to 3v3 or 5v when you connect it? Have you tried reversing your SDA/SCL lines?

Also, interested to know: how well does this work? Does the magnetic fields from the motors interfere with the magnetometer?