How-To #35: Connecting To Adhoc Networks on Android Tablets/Phones

Lets review the basics: firstly, what is tethering and Adhoc WiFi? Tethering is basically the sharing of internet connection of an internet capable device(host) with other devices(clients). 

The host device usually have internet connection from some kind of data plan such as 3G, 4G, and/or Edge. Obviously, it would be a waste of money to purchase data plans for every device that you own. 

To share the internet connection, the host device would create a sort of "hot spot" to build a virtual network through WiFi. One of those type networks is the Wireless Ad-hoc Network.

Skipping the technical details of an adhoc network, just remember that it is not the same as a traditional WiFi network and cannot use the same protocol for connection. While all Android devices are capable of connecting to standard WiFi networks, there are many devices that lacks the ability to connect to Adhoc wireless networks(i.e. most Android tablets cannot do this unless a custom ROM is installed).

Luckily you can enable Adhoc WiFi by following the steps below.

How to enable Adhoc WiFi on Android Tablets and Phones using an App
Arend has released the "WiFI Ad Hoc Enabler" app on the market that automatically does the manual operation below. I highly recommend trying this app first.

Requirements:
-Root
-Busybox(Extra software that is installed on your Android to give you some additional handy LINUX / UNIX based commands. BusyBox is required by many apps)
-May need to disable "Compatibility checker"(open the "Ad Hoc Enable" -> go to Settings.

How to enable Adhoc WiFi on Android Tablets and Phones Manually

Requirements:
- Root
- USB Drivers
- adb session
- Tethering(For the device creating the Adhoc network)

Instructions:

1) Download and Unzip adhoctablets.zip (I downloaded/unzipped to the C:\adhoctablets folder). Now transfer the folder(C:\adhoctablets) to the MicroSD card or somewhere else on the Android Device. 
Note: You may need a wpa_supplicant specifically designed for your device! The one in the adhoctablets.zip is not for everyone*

2) Make sure the drivers for your Android device is installed(read requirement at top).

3) Go into Settings => Applications => Development => Check USB Debugging 

4) On Windows/Linux/Mac open command prompt
Windows users can open cmd prompt by: 
- Pressing WindowsKey+r then type in cmd and press "ok"
OR
- Type %windir%\system32\cmd.exe in any window in the address area
Linux Users:
You should know how this is done already...

5) In the command prompt browse to the adhoctablets.zip. 
In Windows type:
cd \adhoctablets

6) Create an adb shell session
Windows: adb shell
Linux: adb-linux shell
Mac: adb-mac shell

7) Type the following:
su
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
cp /system/bin/wpa_supplicant /sdcard/wpa_supplicant.original
cp /sdcard/wpa_supplicant /system/bin/.
chmod 755 /system/bin/wpa_supplicant
chown system.wifi /data/misc/wifi/wpa_supplicant.conf
exit

Note for last command: if *.conf file is not in /data/misc/wifi/ put the path to the right directory. You may need to use a program like ES File Explorer to locate the file directly.

8) Reboot the Android device

9) Done

Congratulations! Now the device is capable of connecting to any adhoc wireless network. 

Note: If you ever want to revert back - type the following:
su
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
cp /sdcard/wpa_supplicant.original /system/bin/.
chmod 755 /system/bin/wpa_supplicant
chown system.wifi /data/misc/wifi/wpa_supplicant.conf
exit