I used your dtb only from the link I shared above. By using that dtb the i2c node was lost, but when I use the one I compiled it shows all 3 nodes.
I will try again and check.
Update: It worked on my dtb. Great. Works like a charm. Nice fan codes. @hyphop. I have this pkg ready for arch/manjaro with your fan script and have added the i2c3 definition patch in the dtb from next built onwards. And will put fan bg default in autostart.
Update 2: the script works with mainline dtb also without the i2c3 definition patch.
Update 3: worked fine with vim1 v14 but only on manual mode. Bg cannot get temp.
We can redistribute your script right?