RE: [Libusb-devel] Turning a USB port on/off

[Paul A. <ti...@io...>]

Delcom Engineering (www.delcom-eng.com) sells a USB chip that does that and 
a bunch more for $5. Add about $3 in parts and you've got yourself a working 
USB device.

Paul



10:51pm, Dan Ellis wrote:

>> It's starting to look like a second USB device implementing a power
>> switch for the first device is a good idea. Possibly the first device
>> could even be extended with a watchdog circuit.
>
> That would be the best solution.
>
> For USB devices which just require power I would have thought there would be a market for a simple chip which just returns device and configuration descriptors but doesn't have any endpoints beyond 0, and provides a signal to indicate when it has been put into the configured state, which could be used to switch Vbus to the other required circuitry.  I don't know whether anyone sells such a thing, but a cheap PLD could easily be programmed up to do it (at low speed, which is all that would be necessary for just getting the power).
>
> Dan.
>



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You can learn many things from children.
How much patience you have, for instance.
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