Electronics and Robotics Developers Choice: Beaglebone Black

Developers, makers, and hobbyists looking for a better alternative to Raspberry Pi. Now BeagleBoard.org has taken the wraps off a 1 GHz ARM-based board named the BeagleBone Black (BBB).  You can use it as a Computer, Media Center, or the controller of your Robotic Project.  One of the features that I am crazy about is the presents of ADC, PWM and lot of GPIO. As a Electronics and  robotic developer, I like Beaglebone Black and is a wonderful choice!!!!

The 3.4 x 2.1 in (8.6 x 5.3 cm) BeagleBone Black open-source Linux computer comes pre-loaded with the Ångström distro (which will  boot in under 10 seconds) and Cloud9 IDE, freeing up the microSD slot for additional storage. It's based on the Sitara 1 GHz ARM Cortex-A8 processor from Texas Instruments, including a 3D graphics accelerator. There's 2 GB of integrated eMMC flash storage and 512 MB of DDR3 RAM.  HDMI monitor, Keyboard and mouse is not must for a developer, Straight away you can connect BBB to your PC and start Development ( Now it will act like an Arduino). If you connect a Monitor, keyboard and mouse you can use it as a standalone PC.

http://www.facebook.com/BeagleboneBlack

Cost : $45 (Indian Price Approx. Rs.3200 + Shiping)

Processor: AM335x 1GHz ARM® Cortex-A8

• 3D graphics accelerator
• NEON floating-point accelerator
• 2x PRU 32-bit microcontrollers

Connectivity

• USB client for power & debug
• USB host
• Ethernet
• HDMI
• 2x 46 pin headers

Software Compatibility

• Ångström Linux
• Android
• Ubuntu
• Cloud9 IDE on Node.js w/ BoneScript library
• plus much more

Useful Gimp Keyboard Shortcuts for Ubuntu/Debian Linux

Use Keyboard Shortcuts to Speed up your GIMP Work flow

 Zoom Tool
   
    Press the + key to zoom in in increments.
    Press the - key to zoom out in increments
    Press the 1 key to zoom in to 100%, ie one pixel in your image matches one 
     pixel on your monitor
    Press Shift+Ctrl+E to fit the image to the window

  Deselect


  Once you've finished working with a selection, you'll want to deselect it.
    Menu  Select--> None

     Keyboard Short Cut   -  Shift+Ctrl+A

Fill
 
    Press Ctrl+, to fill with the foreground color
    Press Ctrl+. to fill with the background color
    Press Ctrl+: to Fill with Pattern

Reset Foreground and Background colour to Default

Press  D 

Others

Undo    Ctrl+Z
Redo    Ctrl+Y

Crop and Resize    Shift+C

Bucket Fill    Shift+B

Eraser    Shift+E
Toggle rulers    Shift+Ctrl+R
Toggle guides    Shift+Ctrl+T

Merge visible layers    Ctrl+M
Anchar layer    Ctrl+H 

Record your Desktop and Make Teaching Materials with KAZAM in Ubuntu/Debian linux

A simple tool Kazam  will capture the content of your screen and record a video file that can be played by any popular  video players.. It also records audio from any sound input device. Kazam provides a simple and clean user interface, I have tested more screen recorders, but kazam is the best.

  This will help you to make video tutorials. This will support FOUR modes, Fullscreen, All Screens, Window and Area.   you can change frame rate by default it is 15.

Now How to install kazam in ubuntu 12.04
Open a terminal and run the following commands.

sudo apt-get install kazam

If any problem do the following

• sudo add-apt-repository ppa:kazam-team/stable-series
• sudo apt-get update
• sudo apt-get install kazam

Speed up Ubuntu Linux with Swap Fine Tuning

Swapping is designed for Low memory systems. Now a days plenty of RAM space available. RAM is much faster than HDD. Swap uses Hard disk space as virtual RAM. If you reduce the usage of HDD and increase the usage of RAM will boot the performance of your system.

The parameter named  swappiness  controls the tendency of the kernel to move processes out of physical memory and onto the swap disk.

• swappiness can have a value of between 0 and 100
• swappiness=0 tells the kernel to avoid swapping processes out of physical memory for as long as possible
• swappiness=100 tells the kernel to aggressively swap processes out of physical memory and move them to swap cache 

The default value of swappiness  in Ubuntu is swappiness=60.
 Reducing the default value of swappiness will probably improve overall performance for a typical Ubuntu desktop installation.
For Desktop users A value of swappiness=10 is recommended.
For Server , it is better to use swappiness=60

How to Check swappiness value
Open a terminal and type the following command
$ cat /proc/sys/vm/swappiness

How to temporarily change the swappiness value
$  sudo sysctl vm.swappiness=10

 How to permanently change the swappiness value

$ gksudo gedit /etc/sysctl.conf

change the  value of
vm.swappiness = 10

No rebooting required

How to Test the reliability and Speed of your DNS in Ubuntu / Debian Linux

This post will help you to find the reliability and speed of DNS servers .
You need a simple utility traceroute.

how to install traceroute

$ sudo apt-get install traceroute

Now Run the following Command for testing google dns 8.8.8.8

$  sudo traceroute -n -w 2 -q 2 -m 30 8.8.8.8

output

shibu@keralalinux:~$ sudo traceroute -n -w 2 -q 2 -m 30 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  192.168.1.1  1.656 ms  2.233 ms
 2  137.199.0.1  25.909 ms  28.264 ms
 3  228.248.170.102  30.771 ms  33.141 ms
 4  115.114.130.85  79.373 ms  81.546 ms
 5  121.240.1.46  78.806 ms  81.854 ms
 6  209.85.241.21  89.617 ms  92.429 ms
 7  8.8.8.8  88.498 ms  91.208 ms 


If the last line of the output does not list 8.8.8.8 as the final hop, or if there are significant timeouts, there may be a network problem preventing you from contacting DNS servers.

The following command can also use for testing the DNS

$ dig @8.8.8.8 www.google.com.

output

shibu@keralalinux:~$ dig @8.8.8.8 www.depika.com

; <<>> DiG 9.8.1-P1 <<>> @8.8.8.8 www.depika.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- 31859="" br="" id:="" noerror="" opcode:="" query="" status:="">;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.depika.com.        IN    A

;; ANSWER SECTION:
www.deepika.com.    812    IN    CNAME    depika.com.
depika.com.        3352    IN    A    72.167.142.113

;; Query time: 63 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Feb 21 00:20:51 2013
;; MSG SIZE  rcvd: 63
 

How to setup Fast and Reliable Public DNS for Ubuntu Linux

Fast and Free Public DNS Servers are available. It will increase the browsing speed.

The Google Public DNS IP addresses (IPv4) are as follows:

• 8.8.8.8
• 8.8.4.4

Open DNS Ip Addresses(IPV4) are as follows

   208.67.222.222

   208.67.220.220

1. Edit /etc/resolv.conf:

   $ sudo vi /etc/resolv.conf

2. Replace the nameserver lines with, or add, the following lines: For IPv4:
   

   nameserver 8.8.8.8
   nameserver 8.8.4.4

3. Save and exit.

How to unzip a .bz2 file with tar command in Ubuntu Linux

How to unzip a .bz2 file with tar command in Ubuntu Linux


You can easily unzip .tar.bz2 files using command line



    tar -xvjpf filename.tar.bz2

Or

 You can use bunzip2 for unziping and usr normal tar command

This command will only work if you have already bunzip2 installed.

    bunzip2 filename.bz2

Default Password of Raspberry Pi

Default password for Raspberry pi 

Debian Wheezy  

Username : pi     Password : raspberry

Arch Linux ARM 

Username : root     Password : root

How to Install Google drive Client Insync in Ubuntu / Debian Linux

Google Drive is everywhere you are—on the web, in your home, at the office and on the go. So wherever you are, your stuff is just...there. Ready to go, ready to share. Get started with 5 GB free.

Official clints are not available for linux.

 Insync  is an unofficial Google Drive client for Linux, is now available in a repository for Ubuntu and Debian user.

Debian-based distributions

Add Insync as a source

1. Edit /etc/apt/sources.list and add deb http://apt.insynchq.com/[DISTRIBUTION] [CODENAME] non-free
   Replace [DISTRIBUTION] with your Linux distro: ubuntu, debian
   Replace [CODENAME] with your Linux distro codename: for example Ubuntu 12.04 is precise  eg:

   deb http://apt.insynchq.com/ubuntu precise non-free

2. Run this in a terminal:
   

   $ wget -O - https://d2t3ff60b2tol4.cloudfront.net/services@insynchq.com.gpg.key \
     | sudo apt-key add -
   $ sudo apt-get update

Ubuntu with Unity (the default desktop)

$ sudo apt-get install insync-beta-ubuntu

Gnome Shell

$ sudo apt-get install insync-beta-gnome

How to recover windows control buttons in Gnome (no maximize, minimize, close buttons) Ubuntu

How to recover windows control buttons in Gnome (no maximize, minimize, close buttons)  Ubuntu

Metacity is the window manager for Gnome Classic. Compiz is another window  manager. If you are using compiz try the following.

Open a terminal

then type

$ ps -ef | grep -e metacity -e compiz

if window manager is compiz

type the following

$ metacity  --replace

If you want to add it permanently

Go to System -> Preferences -> Startup Applications
click Add

metacity  --replace