Date: Wed, 08 Apr 2015 03:01:17 +0200 From: "Julian H. Stacey" <jhs@berklix.com> To: Matthias Apitz <guru@unixarea.de> Cc: freebsd-usb@freebsd.org Subject: Re: power off 5V on USB port Message-ID: <201504080101.t3811Hx6015481@fire.js.berklix.net> In-Reply-To: Your message "Tue, 07 Apr 2015 15:30:14 %2B0200." <20150407133014.GA1790@c720-r276659>
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Hi Matthias & usb@ Matthias Apitz wrote: > Hello, > > I'm using an Ubuntu smartphone connected on one of the USB ports to my > netbook as a router to the Internet. I wanted to power-off the USB port to > a) save energy in the netbook and > b) not having the phone always charged for the memory effect in the battery. > > I tried: > > $ usbconfig > ... > ugen0.3: <AquarisE4.5 BQ> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA) > > # usbconfig -d ugen0.3 power_off > # usbconfig -d ugen0.3 > ugen0.3: <AquarisE4.5 BQ> at usbus0, cfg=255 md=HOST spd=HIGH (480Mbps) pwr=OFF (500mA) > > as you can see the state is now pwr=OFF, but in this state the USB port > is not longer usable. What is the correct way to shutdown the 5V > provided via USB to the device? > > Thanks > > matthias I assume you'd prefer a software solution, but maybe there's a hardware solutions too. Here's an extract of a mail to a friend: ] I bought a short USB (2) OTG cable for my phone, ] ] http://www.conrad.de/ce/de/product/986693/USB-20-Anschlusskabel-1x-USB-20-Stecker-Micro-B-1x-USB-20-Buchse-A-010-m-Schwarz-mit-OTG-Funktion-vergoldete-St ] Translation: ] https://translate.google.com/translate?sl=de&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.conrad.de%2Fce%2Fde%2Fproduct%2F986693%2FUSB-20-Anschlusskabel-1x-USB-20-Stecker-Micro-B-1x-USB-20-Buchse-A-010-m-Schwarz-mit-OTG-Funktion-vergoldete-St&edit-text= ] ] It works for data, allows phone to access USB sticks & via ] an SDHC adapter those cards too. Cost 7 Euro. ] ] Curiously, it fails to charge phone, maybe there's a reason for that here: ] http://en.wikipedia.org/wiki/USB_On-The-Go Cheers, Julian -- Julian Stacey, BSD Linux Unix C Sys Eng Consultant Munich http://berklix.com Indent previous with "> ". Reply Below as a play script. Send plain text, Not quoted-printable, HTML, or base64.
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