th3count
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Re: HDMI Power?

Tue Feb 14, 2012 1:24 am

Can someone with a little more knowledge please elaborate on this for me. I have read that the raspberry pi will be powered by a 5v USB power source.

Would it not be possible to bridge the 5v from the HDMI to the 5V on the USB and pull power from a display/monitor?

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tzj
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Re: HDMI Power?

Tue Feb 14, 2012 2:06 am

http://www.themagpi.com <---- Checkout the MagPi
(The MagPi - Co-Founder)

jamesh
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Re: HDMI Power?

Tue Feb 14, 2012 8:39 am

That's a useful link. Doesn't mention MHL though, which is an adaption of the HDMI spec to supply decent power as well. However, not supported by many TV's although used by Roku on their HDMI stick device.
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timgiles
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Re: HDMI Power?

Tue Feb 14, 2012 5:37 pm

Was going to mention that it sounds like you only have 7 to 8% of the power needed at 50mA.

rwaltman
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Re: HDMI Power?

Tue Feb 14, 2012 7:29 pm

th3count said:

Would it not be possible to bridge the 5v from the HDMI to the 5V on the USB and pull power from a display/monitor?
I don't know what the official HDMI specs say,  but I don't think this is a viable solution.

The 5Volt line in HDMI is not a general purpose power line.

It is only expected to be used for the "Hot-plug" detect logic, and to provide power to read the EDID information on the transmit side.

That means, very litle power is needed and probably very little power is provided.

--

Roberto Waltman.

kevleyski
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Re: HDMI Power?

Tue Feb 14, 2012 7:54 pm

Yep had similar idea (ala Roku) so just wondering, many TV"s have Ethernet RJ45 so perhaps can draw power from that (or even the CI+ slot in Europe)

(or solar or other induction

Kev

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abishur
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Re: HDMI Power?

Tue Feb 14, 2012 8:15 pm

I'm definitely not one to say it won't work before giving it the ol' college try, but I'm largely confident that amount of current these devices send out would be much too small to power the r-pi.  HDMI sends a max of 50 mA, you'd need 6 HDMI ports to provide enough power to power the Model A.  Ethernet is a larger variable, but I would imagine that any TV ethernet port would be a sink rather than a source for electricity
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th3count
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Re: HDMI Power?

Fri Feb 24, 2012 4:58 pm

Thanks for all the replies, When the raspberry pi becomes publicly available this is what i will try working on until i exhaust all options that I can think of. If i make an progress i will update this thread.

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