3G Dongle only connects for a few seconds

Question

How can I see what's causing my 3G dongle to disconnect from the Internet?

I'm using a Huawei K3565 USB 3G dongle on my Raspberry Pi.

Using wvdial and sakis3g I can connect to my current provider (GiffGaff) - but only for a few seconds.

For example, I can ping 3 - 4 times, or download approx 25,537 bytes.

Then the modem disconnects.

I don't think this is a power issue - I'm using a 1.2A charger with no keyboard or screen attached. I also have sufficient credit :-)

So, any idea what is causing it to disconnect? Which logs can I look at?

Well, that's a good point. Raspberry Pi recommends 700mA for powering the device. Most 3G dongles need no more than 500mA. 500+700=1200. But I'll try with a 1.8A charger to see if that makes a difference. — Terence Eden, Commented Jul 5, 2012 at 15:29
Yes, well that's 700mA for powering the Pi alone. You're trying to power things with it as well. — Jivings, Commented Jul 5, 2012 at 20:03
Interestingly, with a 1.8A charger, it connect for about 3 times as long before suddenly disconnecting. Are there any specific logs I can look at? — Terence Eden, Commented Jul 6, 2012 at 10:14
Not for this. Look at @AlexChamberlain's answer. The usb port doesn't provide enough power for your dongle. — Jivings, Commented Jul 6, 2012 at 10:27

Alex Chamberlain · Accepted Answer · 2012-07-05 21:20:53Z

2

The current on the RPi outputs is limited to 140mA; try it through a powered hub.

answered Jul 5, 2012 at 21:20

Alex Chamberlain

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Kai · Accepted Answer · 2012-10-19 07:51:44Z

-1

I found a tutorial in "Cooking Hacks" explaining how to use 3G with the Raspi through GPIO: http://www.cooking-hacks.com/index.php/documentation/tutorials/raspberry-pi-3g-gprs-gsm-gps

They have launched a shield that allows our Raspi to be connected to a server or to make calls through a 3G Module.

answered Oct 16, 2012 at 8:57

Kai

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If it is possible to include the important part of the external post in your answer, please do so (since the link you provided may not work tomorrow!)
– Dave
Commented Oct 16, 2012 at 9:18

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