Output of uname -a:
Linux cb0063b 4.14.120-yocto-standard #1 SMP PREEMPT Wed Jul 31 19:56:02 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
I have also attached I2C and KERNEL options that I found with grep in /proc/config.gz and the output of lsmod. See:
Furthermore I tested a different i2c device and found that that device does work. However, I cannot get the IMU (a mpu6050 on a GY-521 board) to work.
Hello,
Just to wrap this problem up, it was hardware related.
The GY-521 board has on-board pull-ups to its LDO’s 3V3 for I2C. Through them the UP^2’s IO pins powed up the board! Removing these pull-ups fixed the inconsistent supply.
I’m guessing the way UPboard and UP^2 drive their IO pins is different (internal pull-ups maybe?), that is why it was (partially) working with the UP, and not UP^2.
Maybe this will help someone 
Best,
Ioannis
Hi. Good to hear that you got to the bottom of it. We can then consider this issue closed.
Just chiming in that the latest release, 2.54.2+rev1 should have the GPIO issue solved