irishcanuck wrote: No back-voltage on upstream connection. Widely used with success on the Pi.
What is back voltage anyway? Is it voltage from the Pi returning to the hub or something?
Back voltage or back feeding means that a hub is powering the pi from one of the hubs ports through one of the vertically stacked Type A ports of the pi, not
through the pi's Micro-B power USB port. If this is done, the main polyfuse of the pi is being completely bypassed, so you either need to add some kind of external protection (fuse, circuit breaker, etc.) or you need to rely on any protection that the hub has, if it is even available at all and/or is the proper value. The USB2-HUB-AG7 has a special Mini-B port labeled "USB IN" that is used to connect to one of the vertically stacked Type A ports of the pi, and this connection will not back feed voltage into the pi. The pi is then powered properly by connecting one of the 7 Type A ports of the hub to the Micro-B power port of the pi.