Portable IGate by Raspberry Pi (English Edition)



To make an RPI Igate work portable, we are using WiFi or 3G mobile connection obviously.

And this article concentrates the setup of WiFi & 3G in Raspbery Pi.

Firstly, let’s revise the latest hardware spec of RPI, here is a brief of ver 2.0 .

  • Removed the two 140mA resettable fuse which used protect the USB port.
  • The rest ver 1.0 PCBA shorted the fuse pads by 0 ohm Resistor.

  • Add 2 mounting hole
  • Starting from October 2012, the RAM size increased from 256M to 512M.


Rapberry Pi Ver2.0

Raspberry Pi Modified

My RPI is the first generation, the 2 USB port protected by 140mA X 2resettable fuse separately.

It limited the current supply to the USB devices, and 140mA not enough for USB type

WiFi Dongle, and 3G Dongle.


As it is a portable solution, I do not want to use an external powered USB hub. So I used a copper plate stacked on

the surface of the fuse, then solder to short the fuse.






WiFi Application

We use latest Raspbian OS which build in supported WiFi connection.

The selection of WiFi Dongle

There are many China band name WiFi USB Dongle such as TP-Link, Mercury supplied locally at a lower price.

But RPI is a kind of embedded system which request related driver for external device.

I refer the RPI wiki compatibility list and buy D-link DWA-131 finally.


The setup of WiFi connection is easy, After the RPI boot up & login, enter the X windows.

Select Internet => wpa_gui , then scan network. If it found your SSID, please enter the

parameter of you Wifi network, such as password, encryption method.


After input those parameter, the WiFi connection should be established.

You may try to browse Internet to confirm the setup is OK.

Please logout the X windows. In text mode, type command ifconfig ,

it will display the network connection information, and you will found the WiFi connection status.

Please unplug the network cord while still plugged the WiFi dongle, and reboot the RPI.

The RPI will enable the WiFi connection automatically when no network cord connected during boot up.

Bingo ! The WiFi connection setup compelte.


3G connection

It is quite complicated; I separated on HW & SW section


As it used for portable igate, I bought a 2nd hand Huwai E-180 which is a flickable 3G dongle.


Google to found E-180 got linux driver, but it request setup some config file. It is quite complex for me.

However, there are some open source package for Linux environment.

Tested & found sakis3G is the most easy setup for RPI .

We need install ppp driver before install sakis3G

sudo apt-get install ppp

Then install the sakis3G package

sudo wget “http://www.sakis3g.org/versions/latest/armv4t/sakis3g.gz”

sudo gunzip sakis3g.gz

sudo chmod +x sakis3g

We enter the setup screen of sakis3g after the installation

sudo ./sakis3g –interactive


Enter cslp3 & *99# for my Telco APN info, the 3G connection success.



Quit the setup menu, in text mode; type ifconifg, you will found ppp info .


I am using prepaid card, which request paid money before access the mobile network.

Please enter the X windows, and open a web browser. It will forward to the payment screen.


Select the preferred plan on this screen. The Internet connection success after deduce the charge.

The 3G Dongle connection setup at Raspberry Pi done.

However, the setting will be expired when you unplug the dongle.

You can check it by command: ifconfig ,the ppp connection was disappear.

You need enter the setup of sakis3G to retype parameter *99# again .

So far I cannot found any method to save the configuration permanently.

Whatever from unplug or reboot the RPI.


WiFi vs 3G, Which solution is better ?

The data rate of an Igate is very low, we no need to consider this factor.

And the following factors we may consider:

Power Consumption

here is my testing result:

WiFi Dongle: 3-3.9W

3G Dongle: 3.4-4.6W

Although the power consumption of WiFi is less, but please be remind that it request other device to sharing the WiFi connection.


3G dongle work independently, while WiFi must used with hotspot or WiFi sharing device.


The WiFi may save many SSID config profile, but 3G network configuration are request to change if use other Telco service.


Although the WiFi method requests some devices to sharing the WiFi connection, but these devices,

e.g. smarthpone, WiFi sharing dongle or notebook are very popular now.

Consequently, the 3G Dongle work independently but must under the network coverage.

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