Sunday, May 11, 2014

Win7 access point

OK, this time, its slightly different. It is not about Linux, but about windows 7. I was looking into building an application for pebble watch and while reading about their cloud IDE, I came to know that I need to have both development PC and the Android phone need to be on same wifi network. However, my wifi router was dead long back and I was managing using ad-hoc networks between my laptops. (Well, I had taken over my wife's old laptop after I bought a new one for her and it was running win-7. Since display was dead for that laptop, I have hooked a LCD monitor to it and it was working as my wifi router in adhoc mode)

Now, it was definite that I need an AP at home and thought about buying one. Each one costed more than 1.5K INR or more. And, I had the bad experience of wifi on my D-Link DSL-2730U dying within 3 months of buying it. Actually, it did not die... but, the its dc adapter did and after a few months from replacing the original adapter with a local made one, I noticed that whole device kept rebooting if wifi was on. When the frequency of rebooting became really unbearable, I decided to move to my ad-hoc network. So, the bottom line is, even if I spent 1.5K, there is nothing that I can do for adapter which is not covered under warranty and so, I decided against buying it.

I then read about having the access point setup on the win7 machine. It was much easier than I thought. After a bit of searching on google, I came up with the following solution.


  • Start the command prompt as admin user (type cmd in search box and when cmd appears on top, right click and select run as)
  • The bellow commands will create an AP
    • netsh wlan set hostednetwork mode=allow "ssid=YourNwkName" "key=0Your1Secret3Key" keyUsage=persistent
    • netsh wlan start hostednetwork
  • Change SSID and KEY as per your choice
  • You can see the new virtual WIFI port and set it properties at the same location where you see the normal network adaptors. (Start -> run -> type "ncpa.cpl" sans quotes -> enter)
  • Right click on the adapter that is connected to internet and select properties
  • Select the sharing tab, enable it and select the home network as the newly created network
  • Windows will move home network to some vague IP address block that is not so common. You may change it by editing the IPv4 properties of that network
  • Install a dhcp server and configure it
    • I used the server from http://www.dhcpserver.de/
    • The setup is explained at http://www.dhcpserver.de/dhcpsetup.htm
    • However, I have briefly explained some points to take care below
    • It comes with a firewall, setup the firewall to allow access

Test your network and be satisfied that things work as expected. Now comes the interesting part. How do I turn on this stuff at start-up? Again came google to the rescue :)

  • Create a batch file to create and start hosted network (I saved it as startap.bat)
  • Add dhcp server startup also to it. Final script will look something like below
netsh wlan set hostednetwork mode=allow "ssid=YourNwkName" "key=0Your1Secret3Key" keyUsage=persistent
netsh wlan start hostednetwork
D:\dhcpserv\dhcpsrv.exe -ini D:\dhcpserv\dhcpsrv.ini -start
  • Download and install nssm and the batch script as a startup service to windows
    • I created a run.bat which contained the following line and executed it as administrator by right clicking it
      • D:\dhcpserv\nssm-2.21.1\nssm-2.21.1\win32\nssm.exe install apsrv
    • The above action will bring up a GUI and you can select bash script created in previous step (startap.bat) as the command to run
  • In your scripts, change the paths as per where you have installed dhcpsrv, 
Now a bit about dhcp configuration
  1. Set dns server and gateway
  2. Do remember to turn on firewall
  3. Save the configuration
(I wanted add a few screenshots... but now I am too sleepy...)

Tuesday, March 4, 2014

The price war...

Vishal Tripathi, an analyst at Gartner reportedly believes that the Windows brand still resonates with people. “If people have an option to get a Windows tablet at price that is similar to an Android tablet, they will likely pick it. A low-cost Windows tablet is not going to shake the market but it will help Microsoft gain some consumers who will otherwise go to Android,” he said.
http://tech.firstpost.com/news-analysis/microsoft-releasing-rs-10000-windows-tablets-mid-year-take-android-219367.html

Well, I do not agree to that. Free is FREE. 15 != 0. But, the fact that is really going to go against them is that, people will not pick windows just because there is an option! If that was the case, they should have already been picking up windows mobiles from Nokia. But, they are not doing it!

Reason? Customers have gone more tech savy and they understand what they are getting. They spent 80% of their time in apps. MS has a store with 10^5 apps or a little more. On Android, they have about 10^6 apps. About 10 times more!

Of course,  people have not forgotten name of MS yet. But, they are more familiar with the name of Android when it comes to phones and tablets. The killer apps on any MS OS are office apps. If they are not going to play that trump card by making office dirt cheap, it will be difficult to make people forget about Android.

Again, in past we have seen Amazon, Nokia etc forking Android. Can it happen in case of any MS OS?

So, the bottom line is, MS cannot win by simply reducing the price of OS. They have to catch up on apps, reduce the cost of office suite and learn from Android about how to force your bitter most enemy to come to you for this survival and then help him to survive :) The last point lets you survive in a fiercely competitive market irrespective of whether you win or your opponent wins eventually. Last at least is something that MS can never do. They are good at closing windows to people, but Android has none to close. 

Friday, November 8, 2013

OpenCV

I am back again. Don't know how long I will stay. But, I want to try something with opencv. Eventually this will happen in ARM platform. However, I am starting with my old laptop running ubuntu.

Step-1: Compiling opencv
  1. Download opencv from http://opencv.org/downloads.html
  2. Create a folder where you are going to build this and untar the files there (I did it in /host/opencv. This created opencv-2.4.6.1 folder inside above directory)
  3. For detailed installation steps, you can visit http://docs.opencv.org/doc/tutorials/introduction/linux_install/linux_install.html
  4. I did not have cmake installed. Installed it using command "sudo apt-get install cmake""
  5. I also ran "sudo apt-get update", "sudo apt-get install libgtk2.0-dev" and "sudo apt-get install ffmpeg"
  6. Created 2 folder scripts and release
    1. /host/opencv/scripts -> A folder for my build script
    2. /host/opencv/release -> A folder for saving my release binaries
  7. Created my build.sh in scripts folder. It is pasted below
BUILD_DIR=$PWD/../release/
SRC_DIR=$PWD/../opencv-2.4.6.1/
cd ${BUILD_DIR}
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ${SRC_DIR}
make -j 6
Once you do the above steps, run build.sh and then once the build is successfully completed, enter the release folder and execute "sudo make install".
This will install your  built binaries to /usr/local. This is only building OpenCV. I will talk about building a program using this in another post.
  1.  

Monday, August 29, 2011

Moving to wordpress

I revamped my homepage  by moving it to a hosting provider and migrating to joomla. Fortunetly or unfortunately, Joomla has very good plugins for wordpress and not for blogspot. These plugins allow me to post at my wordpress blog while updates will be made available instantaneously at my home page. I have pulled all the content from flyingtux.blogspot.com to yetanothertux.wordpress.com. Do continue to visit me at

http://yetanothertux.wordpress.com
http://sarin.net.in

Friday, June 24, 2011

QT keyboard events

I am here to make a quick post. I searched for this at many places but could not get the exact solutions. Every message I could read sounded cryptic.

Scenario:
I want to generate fake keyboard events and send to QWebView class.

Solution:
Extend this class to have slots for signals. Connect it to a signal that can pass an ascii character.

Issue:
Keyboard does not have 'a' and 'A'. It only has an 'A'. That means, I cannot directly send any lower case characters using the event (Which is not correct)

Solution:
The solution is simple. The constructor of QKeyEvent can take QString as one of its argument. The signature is as follows:

QKeyEvent ( Type type, int key, Qt::KeyboardModifiers modifiers, const QString & text = QString(), bool autorep = false, ushort count = 1 )





Even if we don't pass the QString, it will work. However, by passing the QString, we can control exactly what will be displayed.
This is how I create my QKeyEvent:


void MyWebView::rcvKeys(int k)
{

char str[2];
str[0]=k;
str[1]='\0';

QKeyEvent *k=new QKeyEvent(QEvent::KeyPress,k,Qt::NoModifier,QtString(str),false,0)

//-----------Pass it to postevent etc
}
}