Which power supply for the B+ model?

[Markino]

Hi guys,
I've just bought my first Raspberry B+ model: I've installed Raspbmc + WiFi USB adapter (Edimax) and I connect it up to the Samsung S3 Mini charger that provide 5V 800mA... everythink works fine even if I connect an USB mouse nut my WD Essential USB3 1TB can't be detect (the light is always blinking).
If I'm not wrong ntfs-3g is just installed so if i type "sudo fdisk -l" I have to see the HD in the list, isn't it?
May be the power supply is not enought?
Which power supply, charger or stuff like that can I search to be sure?

[mahjongg]

if the supply fails, the brownout detector of the B+ will turn off the PWR LED.

But slighter power voltage variations may also cause problems with some susceptible wifi adapters.

Use a good power cable.

[gkreidl]

Hi guys,
I've just bought my first Raspberry B+ model: I've installed Raspbmc + WiFi USB adapter (Edimax) and I connect it up to the Samsung S3 Mini charger that provide 5V 800mA... everythink works fine even if I connect an USB mouse nut my WD Essential USB3 1TB can't be detect (the light is always blinking).
If I'm not wrong ntfs-3g is just installed so if i type "sudo fdisk -l" I have to see the HD in the list, isn't it?
May be the power supply is not enought?
Which power supply, charger or stuff like that can I search to be sure?

Your HD draws too much power from the RPi. This cannot work with a 5V 800mA power supply. You need a good 5V 2A power supply and a good cable (!!!) and you must set
max_usb_current=1
in config.txt to enable 1.2 A for the USB power lines (all 4 of them taken together).
see also here (and the following posts):
http://www.raspberrypi.org/forums/viewt ... 97#p623076

[Markino]

Thank you very much for the info!
Do you know if with the last release of Raspbmc is it possible to put the max_usb_current=1 in the config.txt or it only works on Raspian?

PS: why is needed also safe_mode_gpio=4? What is that feature for?

[gkreidl]

Thank you very much for the info!
Do you know if with the last release of Raspbmc is it possible to put the max_usb_current=1 in the config.txt or it only works on Raspian?

PS: why is needed also safe_mode_gpio=4? What is that feature for?

I'm only using Raspbian, so I cannot tell you. It depends on the system files in the boot partition. "safe_mode_gpio=4" was used in the beginning to set high current USB option and should be replace later with "max_usb_current=1".

[Markino]

Ok, thanks!
So from now on we can just use only "max_usb_current=1" if I understood.

[DirkS]

Do you know if with the last release of Raspbmc is it possible to put the max_usb_current=1 in the config.txt or it only works on Raspian?

Yes, it's available since the July update http://www.raspbmc.com/2014/07/raspbmcs-july-update-2/

Gr.
Dirk.

[Markino]

Perfect!

Last thing: enabling the 1.2A USB power on model B+ and assuming I have a correct power supply (6A?) will I have 1.2A max for each of the 4 USB ports or 1,2A is the max power of the sum of the total power dispatched on all 4 ports?
Just wondering if it will be possible to conenct more then one USB HD directly to the Raspberry...

[DirkS]

It's the total available power for the 4 ports.

Gr.
Dirk.