I would like to isolate the USB connection from mains because I would like to attach a Raspberry Pi instead of the nanoPi. I was thinking about a chip like the ADUM3160 https://www.analog.com/en/adum3160 or ADUM4160. They provide an isolation up to 2.5kV rms and 7.5kV respectively.
They provide a maximum data rate of 12Mbps as specified as full speed in USB 1.0. Which data rate is needed for the openzmeter/STM32? Does it use 1.5Mbps (Low Speed) or 12Mbps (Full speed) or even USB 2.0?