Robotics Resources in Bangalore


During my recent visit to Bangalore I went to S.P road to purchase some electronic kits and found that OM electronics had opened a new shop called “OM Technology center”. A lot of new Robotic kits, Gears, servo motors etc are available here to the hobbyist as well as the student.

Most students who are looking all over Bangalore for parts and spares will definitely find this shop very useful. In addition to the robotics kit the shop also has Vegakit, EFY kits and an in-house kit which they make themselves called techno Kit. These Kits are pretty useful for both Diploma and B.E students.

I hope most students will find this wirte up useful, if so please leave a comment and I will post more 🙂 .

RTLinux resources


RTLinux is a Modified extension to the Linux kernel such that the Kernel acts as a Real time operating system. The small size and the wide variety of platforms supported by Linux makes RTLinux an ideal candidate for embedded applications.RTLinux finds applications in Aerospace, Automobile and Consumer electronics industries.

Here are some useful links to RTLinux related sites

RTLinux application development tutorial.

Another RTLinux Tutorial.

RTlinux reference projects.

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Broadcom WiFi woes – I


I recently inherited a HP ZV6000 laptop, I decided to install Linux on this and began by trying to install Fedora 5. Everything went smoothly, I booted into Linux to find that my WiFi was not working. A little research on the net pointed to the Broadcom 4306 WiFi card that comes with my laptop to be the culprit. Frustrated users of Broadcom abound in various online forums and are fed up with this crappy card.

I tried both NDISwrapper and the FWcutter method but to no avail. I must have been doing something wrong because on most forums people were able to get the card working pretty easily. A few unfortunate souls like me ran into trouble and couldn’t get it to work. I decided I might as well try a different distro so I downloaded Ubuntu linux and installed it, again the WiFi card was not working. I messed around with Ubuntu by following the instructions given on the Ubuntu forums and got the card working but it is very sporadic.

I gave up for a few days and when Fedora Core 6 was released I decided to give it a shot again. I downloaded and installed FC6 but the card still refuses to work. I read on the fedora forum that the WiFi card is PCI-X and needs different drivers. I will try mucking about and see if I can get it working. meanwhile for the unfortunate people who have Broadcom just like me and want to try it themselves here are the links.

Getting Broadcom to work on UBUNTU with NDISwrapper.

Another forum posting for UBUNTU & NDISwrapper.

Fedora Forum search results for Braodcom+4306.

I understand that the Broadcom corporation wants to protect its intellectual property and will not release the source code for the drivers. A few braves souls have reverse-engineered the driver and got the driver built into the Linux kernel from 2.17 onwards. Big companies like HP who bundle such crappy cards should come to the rescue, if they really care about Linux why not release a driver compatible with Linux that works out of the box without us resorting to various serpentine methods? at the very least the should fund the group that is reverse engineering the drivers.

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Kiosk mode browser using XUL


I volunteer at the Warren memorial library and was asked recently to create a Kiosk mode browser that could not be used to browse anything else except for the library’s book catalog. I started exploring the various options available and soon settled on two browsers, Opera and Firefox, while it is fairly easy to setup opera in kiosk mode you still need to pay Opera for the professional version to make it work.That ruled out opera and I was left with Firefox.I started hunting around for an extension that would turn the Firefox browser into a locked down version where you could not navigate to any site. I downloaded the R-Kiosk extension this extension does a pretty decent job of locking down the browser.The extension disables most of the menu items and does a pretty good job in disabling the navigation bar and the address bar,but the extension fails to block the preferences menu item thus leaving a chink in its armor which can be exploited by anyone who is computer savvy. The person can use the preferences menu to set the home page to any desired site close preferences and hit alt+home on the keyboard to navigate to that page.

For e.g if you wanted to restrict the patron from visiting any other site except for the library’s own home page a malicious user could set the home page to something like http://www.google.com and navigate to any site from there. The author also claims that the extension can only be uninstalled from safe mode, but by going to http://addons.mozilla.com and installing any addon you still get access to the addons window and can uninstall the extension from there.

In the end I found that the only way to circumvent these issues was to disable almost all the menu items, this was too much work which included hacking the perf.js file in the profiles folder so I decided to write a XUL widget instead.

Here is the XUL code

<?xml version="1.0"?>
<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
<window
id="google's Online catalog"
title="googleOnline catalog"
orient="horizontal"
width="1000"
height="768"
xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
xmlns:html="http://www.w3.org/1999/xhtml">
<vbox flex="1">
<hbox pack="center">
<html:font face="verdana" color="blue">
<html:strong>
<label value="Google's online catalog"/>
</html:strong>
</html:font>
</hbox>
<hbox flex="1" orient="vertical">
<html:iframe src="http://books.google.com/" flex="1"></html:iframe>
</hbox>
</vbox>
</window>

PS: Copy pasting the code above will not work please download the code here, for some reason the code tag in wordpress does not work with XUL code 😦 properly. once you download the file from the above link rename the file from kiosk.doc to kiosk.xul.

you can preview the above code in this excellent XUL live editor.

googlexul.jpg

On a Mac you can setup a restricted account, set it to auto login without password and then set Firefox to start this XUL file at login. to further prevent access to the OS install the profile password extension for Firefox. This is not an elegant solution but it got the job done.

The XUL file can be started on login with the following command line typed into a shell script

cd /
cd Applications
cd Firefox.app
cd Contents
cd MacOS
./firefox -chrome /nameofxulfile.xul

On a windows machine the default shell can be changed to something like Blackbox which is a minimal shell and can be used for the same purpose, but it isn’t foolproof the only other way is to set the shell as Firefox which I haven’t found a way to do yet.

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FON Heralds the Free WiFi Revolution


FON a startup with a very simple idea is taking the world by storm, FON wants you to share your internet bandwidth. Owners of broadband internet connections and compatible WiFi routers (currently Linksys WRT54G (pre-v5), WRT54GL, WRT54GS and WRT54GSv4, or Buffalo WZR-RS-G54, WHR-HP-54, and WHR-G54S and FON claims more are to be supported in the near future) can participate in the FON network by installing FON’s firmware on their routers. FON is also shipping routers that have the firmware pre-installed for $29.95 including shipping. Currently FON users can either choose to share their bandwidth freely or can choose charge other FON users for access to the internet thru their routers. FON currently supports three kinds of users.

Linus: Linuses are users who share their internet connection freely without charging for it.

Aliens: Aliens are users who do not share their internet connectivity and get charged $3 to access the FON network when available.

Bill: Bills are users who get a share of the money paid by Aliens and do not have roaming access. these users do not share their Bandwidth for free.

Participating in the FON network might sometimes conflict with the terms of use of some ISPs, but FON has entered into agreements with some ISPs to allow DSL-sharing.

FON recently inked a deal to bundle its “La Fonera” router with Skype’s WiFi wireless phone Bundle.

The company which was founded in 2006 has received backing from big players like Google, Skype and eBay.

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Amazon filler item finder


There you are on a shopping spree on Amazon and much to your dismay you find that you are 2 dollars away from qualifying for a free shipping deal, thus ensues a made scramble to find that nifty little knick-knack that could meet your needs and lead you to free shipping nirvana. The Amazon filler item finder is a site that can come to your rescue at just such times. This site finds products that match the amount you specify in such a way that by adding this little item you will qualify for free shipping. While the UI isn’t so great the results are absolutely wonderful. Give it a try and say hello to free shipping every time you shop on Amazon.

Crap cleaner


Crap Cleaner is a nifty little tool that enables you to clean out all the junk and temporary files that mysteriously accumulates overtime on your windows PC. Every time you visit a site or  cookies temporary files and installer related files get stored in the temp folder, while there are a variety of tool that boast many optimization techniques the best so far is CCleaner from http://www.piriform.com/. The software is an effort to provide a utility that does just what it says clean crap from your computer at an unbeatable price “FREE”. On a freshly installed computer running windows XP this tool is able to remove as much as 500MB of junk thus making way for your eclectic mix of Mp3’s from various obscure bands and maybe more space for your files.

CCleaner can also fix certain issues with the registry, It can also be setup to run automatically at startup and for the paranoid “tinfoil hat” types can be setup to erase files by shredding them. It also includes an add/remove programs interface using which you can uninstall programs and a startup editor which can be used to prevent programs from starting up automatically when windows starts. Overall this utility is best suited if you don’t want to spend 20-30$ on a swiss “army knife” of a utility that claims to do everything but does not do anything well.Go ahead and give it a try the small download size and the excellent performance will win you over. Nearly 350 million people have downloaded this utility you should too.

Alternatives to Windows programs


The open source revolution is providing more choices to users than ever before, be it a completely free operating system, a fully featured office suite or very good graphics editing program, the sheer number of alternative programs to some popular proprietary programs is amazing. The following site has a very nice list of programs that provide alternative programs to some propriety ones www.foogazi.com

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configuring ConTEXT editor for Java


A few weeks ago I started learning Java, while searching for a good editor I found ConTEXT editor a multipurpose code editor which supports a wide variety of languages and has support for customizable templates. ConTEXT editor is the best editor I have see that suits a budding programmers needs perfectly. ConTEXT Editor can be downloaded here. Help configuring ConTEXT for java can be found here.

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Codetch Dreamweaver replacement??


In my quest for the perfect Dreamweaver replacement, I have tried a lot of WYSIWYG editors but have not been successful in getting an editor that matches Dreamweaver. There is Nvu but it does not let you edit PHP code, then there is Netscape composer which is the same as Nvu. There are a number of other editors like Matrix y2k editor, PHP designer2006 etc but none of them match or measure up to Dreamweaver.

Enter Codetch although not a full replacement to Dreamweaver it is rapidly evolving into an editor that can take on Dreamweaver some day. Codetch is an Addon for Mozilla Firefox. It is a XUL based HTML editor that uses the Gecko rendering engine to provide a easy to use and flexible editor that fits right inside the browser. Some of the features of this editor include an ability to load inside a tab or a floating window, an integrated java console and a live preview feature. The editor is at its nascent stage and does not support syntax highlighting nor does it support scripting languages like PHP. The best feature is the integrated help browser that connects to GotAPI.com which provides an web2.0 based searchable interface to help manuals of various programming languages.

The features that I would like to see incorporated the most in Codetch is syntax highlighting, more shortcuts to HTML tags, a CSS editor, Support for PHP and other scripting languages and finally code completion. Overall its the best XUL based editor I have seen so far and holds a lot of potential in the future.You should definitely check this extension out.

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