Can a 3G dongle directly plug into Raspberry Pi model B+ board without powered USB hub?

Dear PI enthusiasts, can a 3G dongle directly plugged into a Rasp Pi model B+ board without the need of powered USB hub? Thank you.

0 hawkeyethehacker over 11 years ago

Which 3G Dongle are you looking at? Someone else may have tried it already.
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0 tekmeister over 11 years ago
The answer depends on a number of factors:

the power requirements of the 3g dongle
the capabilities of the supply you are using to power the Raspberry Pi
the USB current limit set by the config
what other USB devices are plugged in
what else the Raspberry Pi board is driving (eg. PiCam, external boards)

Make sure your power supply can supply enough current to handle everything. The Raspberry Pi B+ by itself is going to draw 1-1.5 Watts or 200-300mA. Also be aware the cable between the supply and the Pi can make a huge difference - the voltage will drop too low as the current draw increases.

Your results are going to be very dependent on the dongle, but I know 3G dongles can be rather power-hungry.

If your dongle is peaking over 600mA, you'll also need to make some configuration changes: Raspberry Pi • View topic - B+ USB 3G dongles OR USB Drive may trip brownout detector
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0 Problemchild over 11 years ago

Probably work until your dongle made a call in which the current would rise rapidly. Personally I would not try this as if it worked some of the time if it needed to make a call to a distant cell the power levels will rise and if this exceeds your Pi's ability to deliver current it will just cause random resets ...Use a separate power supply/HUB.
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0 Problemchild over 11 years ago in reply to Problemchild

On the RPF some one got a device working on the Pi directly
http://www.raspberrypi.org/forums/viewtopic.php?f=46&t=76715

But most consider it risky ...personally you may be lucky ...doesn't mean you will be lucky all the time you ...need to keep the solution repeatable so probably a hub will be good!
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