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USB Monitor?

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Is there software available that would report the current supplied by a USB port? For example, I have a device hooked up to the port, and I want to know how much current is it currently drawing.
 
Figured the computer might already measures it internally anyway.
No, It has no way of knowing exatly how much current is being used, you would need more hardware for that. But it does set USB ports to 200ma or 500ma.
 
4pyros... if it can't sense currents then how does it set USB ports to 200ma or 500ma? There HAS to be a detect mechanism of some kind for over current, no if ands or buts. Even if it's a low voltage dropout sense on the ports output line.
 
This is a good explanation of power and the USB port(s). Scroll down to the Power section.

As to over current, it really depends on the motherboard and specifically the quality of the motherboard. They use chips similar to this one.

As to measuring the actual current? Beyond adding some hardware inline like a small meter I have no idea as I do not believe the data is available through a software solution. Also no clue as to the newer USB3 interface or protocol.

Ron
 
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if it can't sense currents then how does it set USB ports to 200ma or 500ma?
A new device will ask for 200 or 500 ma when its pluged in. Its part of the protocol.
There HAS to be a detect mechanism of some kind for over current, no if ands or buts.
Yes its called a fuse. Cheap and easy.
Even if it's a low voltage dropout sense on the ports output line.
Maybe hard wired into the port driver but not accessible thru software.
 
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