Powering Peripherals

[TonyDiver]

Hi,

I want to set up my Pi with a powered USB hub. I understand that by powering the hub I can use it to power the Pi with a USB/5V cable. I also want to plug in a wifi adapter, a 250gb hdd, potentially a keyboard and mouse and maybe some other stuff.

The hub I plan to use is 1A.

Will that power my Pi and all peripherals?

Thanks in advance,

Tony

[joan]

Possibly. It may be marginal depending on the hard drive. I think the Pi needs half an amp at 5V.

[TonyDiver]

The HDD would be a 250gb. I want NAS storage to configure TM backups, you see. What do you think?

Thanks.

[Mobius]

The HDD size is not the important factor, it's the power consumption. You should be able to find power consumption specs for it. I would say that you probably need more than 1 amp to be on the safe side given all of the peripherals you mention. From what you say, you will need a hub that has more than four ports and that may be a problem. Many hubs use a pair of four ports circuits and there have been reports of those not working with the Pi. Check out this page: http://elinux.org/RPi_VerifiedPeripherals

[penguintutor]

It will depend on the hub and the HDD.

Even if the total power to the hub is sufficient it depends upon how it supplies power to each of the ports. I have a HUB with a 1A supply which is not able to power the Pi even with nothing else connect.

The Pi powers up, but then fails during the boot process and reboots itself. The same hub is not able to power up both a wireless keyboard and wireless mouse simultaneously - consequently that hub is being used for something else and I had to get a "better" hub which was able to power all of them at the same time.

The only sure way is to try and see if it works, if you get strange behaviour then try with a different power supply.