Critanime
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Pi 2 power question

Fri Feb 13, 2015 10:54 am

Hi fello Pi'ers!

I bought two Pi 2 B's. One to tinker with and one as a emulation station. This question relates to the Pi that's going to be the emulator.

Are there any good all in one solutions for powering the Pi and also been a hub?

I'm planning on using a Xbox style controller, wireless keyboard and mouse combo and a wifi dongle. I can find powered hubs but I want one that powers everything and doesn't need a separate hub.

The project will go into a dead Atari 7800 case. So space is tight.

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DougieLawson
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Re: Pi 2 power question

Fri Feb 13, 2015 3:21 pm

Why do you need a hub the PI2B has four ports? With

Code: Select all

max_usb_current=1
in /boot/config.txt you can run high power USB devices from there (as long as the microUSB power supply is good enough).
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Critanime
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Re: Pi 2 power question

Fri Feb 13, 2015 4:47 pm

Thanks for the reply!

I didn't know how much power the Pi could output through its own ports. So I wanted a powered hub to just make sure there was enough to power possibly two wired Xbox style controllers, a wifi dongle and wireless mouse and keyboard dongle.

But that code makes life easier because the project for the emulator has shifted to a dead dreamcast. So space isn't so much if a issue.

What kind of power supply would you recommend if I was to boost the power through the ports?

electronicman
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Re: Pi 2 power question

Fri Feb 13, 2015 6:26 pm

Hi I just got a Pi2 and my first experience was not so good. It turned out that the old power problem is back with Pi2. You really need a good PSU as it consumes more current. I have a number of 5VDC phone type chargers that do not work with the Pi2, so I used a home made PSU that worked very well.
There are some chargers that put out 1.5 or more Amps so I would get one of these if you can
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Re: Pi 2 power question

Fri Feb 13, 2015 7:21 pm

electronicman wrote:Hi I just got a Pi2 and my first experience was not so good. It turned out that the old power problem is back with Pi2. You really need a good PSU as it consumes more current. I have a number of 5VDC phone type chargers that do not work with the Pi2, so I used a home made PSU that worked very well.
There are some chargers that put out 1.5 or more Amps so I would get one of these if you can
Well, there are 4 cores now, not just one, so when running full tilt there is a bit more power demand. But at idle it should be about the same. It's not a question of an old problem coming back, just a more powerful chip needs a more powerful supply.

That said, the P2 I have runs of one of my laptop USB port, but won;t run of a powered hub. At least, not when the camera is one and someone else is logged in over SSH and doing stuff. (Yes, we are multi-usering a P2)
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pantag
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Re: Pi 2 power question

Fri Feb 13, 2015 7:53 pm

I have a wireless KB/Mouse combo and an external USB HD 7200RPM and it is powered by the RPI2, using a 5V, 1.5A PSU.

As DL mentioned above, in order to "unlock" RPI2 to provide 1.2V power to its USB ports (instead of the standard 600mv), you NEED to add this line to the config.txt file:

max_usb_current=1

I did it and it works great. If you don't do this, you basically have a RPI model 1B as far the USB power goes, which would entail the annoying use of powered hubs.
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RPi 2 B
RPi B

Critanime
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Re: Pi 2 power question

Fri Feb 13, 2015 11:15 pm

Will doing this fix the slow wifi issue?

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DougieLawson
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Re: Pi 2 power question

Fri Feb 13, 2015 11:59 pm

Critanime wrote:Will doing this fix the slow wifi issue?
It's exceedingly unlikely to have any effect on WiFi.
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Critanime
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Re: Pi 2 power question

Sat Feb 14, 2015 7:26 am

Ok. Thanks for the feedback. I ordered a 2.1a power supply from CPC (would rather get it from a place like CPC than eBay after I bought something similar that exploded.) so should be here Monday. At the moment I am using my iPad charger. But my wife is complaining about having to share it lol. :lol:

hhoanganh
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Re: Pi 2 power question

Sun Feb 15, 2015 4:19 am

currently i get power for my Rasp B+ by using USB port of a TV, because my project needs the B+ on and off at the same time as the TV, it works for over 6 months. Is the version 2 ok with this type of power supply ?

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