MobileRead Forums - View Single Post

Quoth · 04-20-2020, 04:14 AM

Two for data (a twisted pair for a bidirectional channel, not separate Transmit and receive) and two are for power, not specifically actually for charging. Originally no USB devices had batteries. Like wired mouse, keyboard, serial adaptor, Memory stick, DVD drive or HDD today.
Micro USB has a 5th pin only used in the plug to "tell" a gadget to be in USB Host mode instead of USB slave mode. Very few gadgets can charge on the same connector when in USB Host mode and if they can, you need a Y cable. Not all micro USB gadgets support host mode, such switching is called USB2Go.

04-20-2020, 04:14 AM	#15
Quoth Still reading Posts: 14,170 Karma: 105212035 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	Two for data (a twisted pair for a bidirectional channel, not separate Transmit and receive) and two are for power, not specifically actually for charging. Originally no USB devices had batteries. Like wired mouse, keyboard, serial adaptor, Memory stick, DVD drive or HDD today. Micro USB has a 5th pin only used in the plug to "tell" a gadget to be in USB Host mode instead of USB slave mode. Very few gadgets can charge on the same connector when in USB Host mode and if they can, you need a Y cable. Not all micro USB gadgets support host mode, such switching is called USB2Go. Last edited by Quoth; 04-20-2020 at 04:17 AM.