Setting up wifi on Raspberry Pi

I recently bought a "NETGEAR wifi dongle" fo my Raspberry Pi so free it from the wired ethernet connections. The details of the wifi dongle is as follows:

$lsusb
Bus 001 Device 004: ID 0846:9041 NetGear, Inc. WNA1000M 802.11bgn [Realtek RTL8188CUS]

To configure it to the local wifi network:

modify /etc/network/interfaces as follows
For example if my wifi network's name is "~Jaguar~" and password is "Password123"

auto lo

iface lo inet loopback
iface eth0 inet dhcp
allow-hotplug wlan0
auto wlan0
iface wlan0 inet dhcp
        wpa-ssid "~Jaguar~"
        wpa-psk "Password123"

Softreboot the system and wifi should be working.

$ sudo shutdown "now" -r

To re-confirm

pi@raspberrypi ~ $ ifconfig
eth0      Link encap:Ethernet  HWaddr b8:27:eb:ae:b2:aa  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:95 errors:0 dropped:0 overruns:0 frame:0
          TX packets:84 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:9356 (9.1 KiB)  TX bytes:13962 (13.6 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:6402 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6402 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:19282157 (18.3 MiB)  TX bytes:19282157 (18.3 MiB)

wlan0     Link encap:Ethernet  HWaddr 84:1b:5e:92:bf:e8  
          inet addr:192.168.1.8  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2182 errors:0 dropped:2359 overruns:0 frame:0
          TX packets:2001 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:289214 (282.4 KiB)  TX bytes:1055742 (1.0 MiB)

and

 pi@raspberrypi ~ $ iwconfig  
lo        no wireless extensions. 
 
wlan0     IEEE 802.11bg  ESSID:"~Jaguar~"  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency:2.412 GHz  Access Point: 80:A1:D7:8D:A3:24   
          Bit Rate:54 Mb/s   Sensitivity:0/0  
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=100/100  Signal level=100/100  Noise level=0/100
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0  
 
eth0      no wireless extensions.  

For Internet to work: use
$ sudo /sbin/route add -net 0.0.0.0 -gw 192.168.1.1 wlan0
where 192.168.1.1 is gateway of my router.

Hope this post helps. :-)

Remote Desktop of Raspberry Pi onto Ubuntu/Android/Windows

I recently bought a Raspberry Pi board from crazypi.com. Raspberry is a low cost chipset from Broadcom which can host linux and many other OS. It just costs 3K INR if you buy it in India. It is an awesome lowcost chipset with 2 USB ports, one ethernet port, one HDMI port, one TV out and one audio jack port. It also has a micro-USB power input and SD card, from where the OS boots.

Now I am gonna explain how to setup remote desktop from Raspberry Pi to Linux or Windows PC. VNC and RDP protocols are famous for desktop sharing. Both have their advantages and disadvantages. However I prefer RDP over VNC, because VNC often gets stuck while using Desktop sharing. I am gonna explain setting up of both the protocols on Raspberry Pi:

1. Using VNC protocol
Server Configurations on Raspberry Pi:
- Install tightvncserver on the Raspberry

$ sudo apt-get install tightvncserver

- Enter passwords if prompted.

- start the vncserver with the following command

$ vncserver :1 -geometry 800x600 -depth 32 -pixelformat rgb565

   
- Now you are ready to connect to Raspberry Pi remotely from any VNC client either on Ubuntu or Android.

Client Configurations:
On Ubuntu: install vncviewer, to connect remotely, install necesarry packages when prompted.

$ vncviewer 192.168.1.3:5901

   

On Android: Download VNC client app from Android market. I downloaded "androidVNC" app from market, works well on my Galaxy Nexus.

Nickname: raspberry:1

password: <type in the view password set while installing vncserver on Raspberry Pi>

Address: <enter ip address of RPi; ex: 192.168.1.3>

Port: 5901

- To kill the server

$ vncserver -kill :1

However I was unable to browse comfortable using VNC so I decided to use RDP protocol. RDP is faster and preferred over VNC and it performs better.

2. Using RDP protocol
Server Configurations on Raspberry Pi:
- Install the xrdp package on Raspberry Pi

$ sudo apt -get install xrdp

- Thats it, the server is ready on RPi. Restart if required.

Client Configurations:
On Ubuntu: Applications > internet > Terminal server Client

Computer: 192.168.1.3
Protocol: RDPv5
User name: pi
Password: raspberry

Alternatively you can use the rdesktop command from the shell as follows:

$ rdesktop -u pi -p raspberry 192.168.1.3 

On Android: Install a RDP client, I used "AccessToGo Remote Desktop/RDP" and "Ahope RDP Client"from Android market. plugin the details as required.

This is really coooooooooool.

Using Rapberry Pi Command Prompt on other devices:
In addition, to access Raspberry Pi in command shell
On ubuntu: 

$ ssh pi@192.168.1.3 

On android: Download "ConnectBot" app from the Android market. Plugin the details and you are ready to go. :-)

You can expect some more stuff on Raspberry Pi sooner.

See you...

Taking wireless logs using wifi

Hey Guys,

Recently I have been trying to use connect USB devices to my Nexus S (running Android Jellybean 4.1.2) using an OTG cable. But unfortunately, on connecting the OTG cable we cant take logs to debug. I tried to find a way out of this to take real-time logs using wifi.

On googling I found a way which worked for me.

The task involved two steps:
1. rooting the device
2. using app to start wifi adb

Rooting the device:
a) Download  RootnexussJB.zip from
http://dl.xda-developers.com/attachdl/2b5b28d0b7d10c2d5529e0b8d6d92746/50bb3158/1/2/2/0/8/4/7/RootnexussJB.zip and unzip it in local machine.
b) use "fastboot flash recovery recovery-twrp-2.2.0-crespo.img" to flash recovery binary adn recovery boot using "fastboot reboot recovery".
c) Choose “Mount” > “Mount USB Storage” > Copy the Superuser 3.2_RC.zip to the internal storage of your Nexus S > Choose “Unmount” on your Nexus S.
d) Choose “Install” > Choose “Superuser 3.2_RC.zip”.
e) Choose "Swipe to flash" > Choose “Reboot System”.
f) Nexus S shows now superuser app in launcher. the phone is now rooted. Congratulations... !!!

jai@jai-laptop:~$ adb root
adbd is already running as root

Courtesy: http://forum.xda-developers.com/showthread.php?t=1795167

using app to start wifi adb:
download any of the wifi adb/wireless adb app from the GOOGLE PLAY STORE. I have downloaded "wifi adb" which requires superuser permissions for wifi adb to work.
a) Open the app and click on "Turn On"
b) Grant superuser permissions to the app when prompted.

c) On your PC connect adb using wifi:

$ adb connect 192.168.1.3.:5555
connected to 192.168.1.3:5555 --> on successful connection
$ adb shell
$ cat /proc/kmsg --> to take kernel logs

Hope this helps,
Jai

Creating an overlay on Android Framebuffer

Hey Guys,

Recently I tried something really crazy. I m not really good at Java, so I was trying to find out an easy way of displaying an image on frame buffer without having to write a Java program. Here is how it works

Prerequisites:
1. Phone must be rooted.
2. Android platform build setup ready. I have downloaded the Android jellybean 4.1.1 from source.google.com at $PROJECT = /home/jai/NexusS.


create a folder in lcdtest in $PROJECT/external/ and add the following two files
    $PROJECT/external/lcdtest/lcdtest1.cpp
    $PROJECT/external/lcdtest/Android.mk

lcdtest.cpp looks as follows:

#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <linux/fb.h>
#include <sys/mman.h>
#include <sys/ioctl.h>

int main()
{
    int fbfd = 0;
    struct fb_var_screeninfo vinfo;
    struct fb_fix_screeninfo finfo;
    long int screensize = 0;
    char *fbp = 0;
    int x = 0, y = 0;
    long int location = 0;

    // Open the file for reading and writing
    fbfd = open("/dev/graphics/fb0", O_RDWR);  //use "/dev/fb0" in linux
    if (fbfd == -1) {
        perror("Error: cannot open framebuffer device");
        exit(1);
    }
    printf("The framebuffer device was opened successfully.\n");

    // Get fixed screen information
    if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo) == -1) {
        perror("Error reading fixed information");
        exit(2);
    }

    // Get variable screen information
    if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo) == -1) {
        perror("Error reading variable information");
        exit(3);
    }

    printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);

    // Figure out the size of the screen in bytes
    screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
    // Map the device to memory
    fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0);
    if ( fbp == NULL) {
        perror("Error: failed to map framebuffer device to memory");
        exit(4);
    }
    printf("The framebuffer device was mapped to memory successfully.\n");

    x = 100; y = 100;       // Where we are going to put the pixel

    // Figure out where in memory to put the pixel
    for (y = 100; y < 200; y++)
        for (x = 100; x < 200; x++) {

            location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) +
                       (y+vinfo.yoffset) * finfo.line_length;

            if (vinfo.bits_per_pixel == 32) {
                *(fbp + location) = 0;100; //100;        // Some blue
                *(fbp + location + 1) = 255;//15+(x-100)/2;     // A little green
                *(fbp + location + 2) = 0;//200-(y-100)/5;    // A lot of red
                *(fbp + location + 3) = 0;      // No transparency
            } else  { //assume 16bpp
                int b = 10;
                int g = (x-100)/6;     // A little green
                int r = 31-(y-100)/16;    // A lot of red
                unsigned short int t = r<<11 | g << 5 | b;
                *((unsigned short int*)(fbp + location)) = t;
            }

        }
    vinfo.activate |= FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE;
    if(0 > ioctl(fbfd, FBIOPUT_VSCREENINFO, &vinfo)) {
    printf("Failed to refresh\n");
    return -1;
    }
    munmap(fbp, screensize);
    close(fbfd);

    return 0;
}

Contents of Android.mk

ifneq ($(TARGET_SIMULATOR), true)

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES:=\
    lcdtest1.cpp

LOCAL_CFLAGS:= -g
LOCAL_MODULE:= lcdtest1
LOCAL_MODULE_TAGS := optional

include $(BUILD_EXECUTABLE)

endif

Now the files are ready. To build the file for Nexus S, first setup the build environment as follows.
Go to $PROJECT directory

$ source build/envsetup.sh
$ lunch full_crespo-eng

Now the build environment is ready. To build the android binary in the shell type

$ make -j4 lcdtest1

This would create a binary at out/target/product/crespo/system/bin/lcdtest1

To run this on Nexus, connected the rooted Nexus S device

$ adb remount
$ adb push out/target/product/crespo/system/bin/lcdtest1 system/lib
$ adb reboot

After phone has restarted:

$ adb shell
# lcdtest1

You would see a green overlay patch as shown.

Green patch on top of display

Good luck and Enjoyy !!!!

Integrating GAPPS in custom binary

Hey Guys,

As I have mentioned in my last post that Google account is not integrated in the custom source that we download from the Android site. I later learnt that this violates the licensing agreement. So we don't get google account integration with the cyanogenmode binaries. So here is a method I found on the internet to integrated the Google account and apps with the custom binary built from the source code:

• Download the clockworkMode Recovery binary for Google Nexus S (recovery-clockwork-6.0.1.0-crespo.img) from http://www.clockworkmod.com/rommanager
• Then you can download the GAPPS from http://goo.im/gapps/gapps-jb-20120726-signed.zip.

Now we are ready to flash on the device:

$ fastboot flash recovery recovery-clockwork-6.0.1.0-crespo.img

$ fastboot reboot recovery 

Device in Recovery boot mode

This will install the recovery binary onto your device. Now we can do a recovery boot to browse the menu and install updates from the sdcard. To browse use vol up, vol down and power button.

• Go down to "mounts and storage" > "mount USB storage"
• Copy the GAPPS zip gapps-jb-20120726-signed.zip to device sdcard storage.
• Select "install zip fron sdcard" > "choose zip from sdcard"
• locate gapps-jb-20120726-signed.zip.
• Reboot the device. 

Integrated GAPPS to custom binary

Custom binary properties :-P

 Now google apps are integrated to your custom binary.
 - Jai

References:

http://jim-zimmerman.com/?p=821

Using Fastboot to download binaries

Hey Guys,

Recently I have been experimenting a lot with The Nexus S. I have also compiled Jellybean Source code in my local machine running on Ubuntu 10.04 (64bit). But unfortunately, the build does not allow you to attach google acount to it :-( . And the default google apps like Play store/Gmail/Maps/Gtalk are absent in the binary. Will look for a method to integrate the Market !!!!

Its easier to flash using Odin (just tar the boot.img, system.img, recovery.img and userdata.img) in Windows platform. For Linux we have two options:

1. Use Fastboot (http://source.android.com/source/building-devices.html)
2. Use Heimdall (http://www.glassechidna.com.au/products/heimdall/)

To download binary using Fastboot:
Download the android-sdk from http://developer.android.com/sdk/index.html
Add tools and platform-tools to PATH variable to use it from any location.

$ gedit ~/.bashrc & and add the following line:
export PATH=$PATH:/home/jai/bin:/home/jai/Android/android-sdk-linux/tools:/home/jai/Android/android-sdk-linux/platform-tools

Now, Download the Nexus Factory image binary from https://developers.google.com/android/nexus/images#sojujro03l

Unzip it. It would have the following 5 files:

1. bootloader-crespo-i9020xxlc2.img - bootloader binary
2. flash-all.sh - shell script to install radio, bootloader and platform
3. flash-base.sh - shell command to install radio and bootloader
4. image-soju-jro03l.zip - the Platform package
5. radio-crespo-i9020xxki1.img - Radio binary

I have skipped the bootloader and Radio binary, as its not good to mess with the bootloader. The device will be useless if the bootloader is corrupted. So better don't mess with it. Then unzip image-soju-jro03l.zip to get the following files:

1. android-info.txt
2. boot.img
3. recovery.img
4. system.img
5. userdata.img

I modified android-info.txt to add a check my bootloader version:

require board=herring
require version-bootloader=I9020XXLC2|I9020XXKL1
require version-baseband=I9020XXKI1|I9020UCKJ1|M200KRKC1

and zipped them to JAI.zip

 zip JAI.zip android-info.txt boot.img recovery.img system.img userdata.img

Now we are ready to flash the binary. Get the device in fastboot mode using the key combination vol up + power button or just type:

fastboot reboot bootloader

fastboot -w update JAI.zip

To flash the binary made from the workspace.

export ANDROID_PRODUCT_OUT=/home/jai/NexusS/out/target/product/crespo/

fastboot -w flashall 

Now my self compiled binary is flashed. It feels great to see it working :-). For any queries mail me.

Jai

Got my Nexus S

Got my Nexus S from Korea today..... !!!!

I just love it...

Its was KOREAN phone ICS 4.0.4..(model: M200) , before I converted it to international version (I9020) by flashing the factory images from Google (https://developers.google.com/android/nexus/images) using ODIN.

The phone bootloaders are generally locked that means one can not flash custom binary till its unlocked. The bootloader can be unlocked by using fastboot tool (<android-sdk>/platform-tools) provided in the android-sdk.

To unlock the bootloader:
1. Get the phone in fastboot mode by pressing the key combination ( Press and hold volume up + Press and hold Power button) or by using adb type

Device in Fastboot mode

 $ adb rebootbootloader
 

2. Unlock the device by 

 $ fastboot oem unlock
 

3. Chose the unlock option from the menu.

Now the device is ready to download custom binary. Now Korean phone can be converted to Non-Korean by just flashing the Platform binary released from Google (https://developers.google.com/android/nexus/images). I downloaded

Factory Images "soju" for Nexus S (worldwide version, i9020t and i9023) version: 4.1.1 (JRO03L) and unzipped it to get boot.img, system.img, recovery.img and userdata.img.

Now to flash the platform binary using Odin:

1. create proper file for the Odin software 

 tar -cvf PLATFORM.tar boot.img system.img recovery.img userdata.img

2. Put the phone in Odin mode using appropriate key combination (Vol up + vol down + power (less than 1 sec and release power) in Nexus S).

Nexus in Odin mode

3. Once the device gets detected in Odin select PLATFORM.tar from PDA and start the download.

After flashing the device is now upgraded to Jellybean 4.1.1 and moreover its a non-Korean phone now.... !!!!

I am gonna dig more into Nexus S.... So many more things yet to come.... !!! ;-)

Jai