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I'll add another question: Does USB-C have a spec for requesting additional wattage? Example: I have a USB-C Printer/Hard drive/or otherwise, and plug in my Ma

I'll add another question: Does USB-C have a spec for requesting additional wattage? Example: I have a USB-C Printer/Hard drive/or otherwise, and plug in my MacBook Air, will it charge my MacBook or will I need an intermediate like a specialty hub to charge? This seems egregious if every device needs to provide power for the potential of charging device in question...

sharth 12y ago
http://www.usb.org/developers/powerdelivery/ http://www.usb.org/developers/powerdelivery/
ghostly_s 12y ago
There's actually a supplemental spec, USB-PD(Power Delivery) which now accopmanies USB 3.0 and addresses this. It is carried over the USB physical layer but does not rely on the data layer for communication.
ghostly_s 12y ago
To answer more specifically; yes— not only is every node in the bus network addressable for power needs and capabilities, even each of the two ends of a cable is a separately addressable node (mostly used to figure out which way a swappable cable is oriented, I think).
azdle 12y ago
It does, but it's not a requirement for all devices so you may or may not need a hub to provide power back to the laptop depending on the device. https://en.wikipedia.org/wiki/USB#USB_Power_Delivery https://en.wikipedia.org/wiki/USB#USB_Power_Delivery
Bjartr 12y ago
According to what I can find[1][2], USB 3 supports 100W and a standard C connector supports 5A. [1] http://www.usb.org/press/USB_Type-C_Specification_Announcement_Final.pdf http://www.usb.org/press/USB_Type-C_Specification_Announceme... [2] http://www.usb.org/press/presskit/USB-IF_IDF_Shenzhen_2014_Press_Deck_Final.pdf http://www.usb.org/press/presskit/USB-IF_IDF_Shenzhen_2014_P...