Hi, new to the forum and currently in the planning stage for my R-Pi !
I have a few questions, some related to USB and how it works.
1) Can one of the R-Pi's USB ports power a non-externally powered USB-hub with 4 ports.
I plan to connect a WiFi-dongle, flash drive, keyboard/mouse receiver and then leave one port free for future use.
I've read that one USB port only puts out 500 mA, will this be enough?
2) If this isn't enough, can I wire my PSU so that it send power through the R-Pi's second USB port, onto the board and out through the first port and help drive this hub, or do these ports have separate 5V lines?
3) What exactly does a non-externally powered USB-hub do? Are the ports' wiring simply connected parallelly? Does it contain any logic or is that taken care of by the USB-controller on the R-Pi?
Below is a sketch of the above. If this doesn't work, would one solution be to buy an externally-powered hub to tear down, and feed the 5V lines directly via my R-Pi PSU? I'd rather not have 1 PSU for the R-Pi and one for the hub.