On Mon, Jul 9, 2018 at 10:00 PM, Xiaofan Chen wrote: > On Mon, Jul 9, 2018 at 2:50 PM, Christopher Head wrote: >> >> The USB 2 specification (and many others) is freely available from usb.o= rg. > > Which is actually a pretty good document to read. > > usb.org also has compliance testing software to download. > http://www.usb.org/developers/tools/ > > Vendors like Keysight offers electrical compliance test fixture > and test software but they are not cheap. > > As for the power issue, I think powered hub is a good solution. > For cable, usb.org has the info as well. http://www.usb.org/developers/compliance/cable/ http://www.usb.org/developers/compliance/cable/CabConn20.pdf --=20 Xiaofan --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .