This post is pretty late too. Here is what I managed to do using script.aculo.us for the proceedings CD of Intesy. It’s not much. It’s not even close to good. Download the zip here, extract and open index.html. And do tell me what you think.

The day was totally hectic. I spent most of my morning working on the Proceedings CD. I’ve used script.aculo.us to design the interface, and the effects look cool. Sort of. I’ll put it up here after a few days.

And most of the evening was spent on walking. Most of us had to. And the juniors did really great. Especially the second years. Things were up and rocking in no time. But I guess the final years could have done better. I, in particular, could have done much better. I wasted most of the afternoon on things others were already working on and so, we’re now lagging on hall arrangement.

The event starts at 9:30AM tomorrow, and I have to reach there by atleast 8:00AM for the computers and projectors to be ready. And I’m supposed to help setting up the computer lab to conduct Simtrix, which is the simulation event.

I hope it all goes well. Pray for us, people.

And surprisingly, I have planned to crash very early tonight. Have to get up early tomorrow.

Well, this post is a bit late actually. I haven’t been able to find time or the patience to write lately. Intesy is the Instrumentation Technical Symposium, organized by the Electronics and Instrumentation Engg. Department (i.e., my department) at college.

This year’s version was announced quite a while back and is on the 19th and 20th of this month. We’ve invited people from other colleges for presenting their papers and projects, and the winners earn hot cash.

We also have two more events for the participants. Once is a technical quiz, and the other one is a simulation contest called Simtrix. Well, I do think the name of the simulation event is stupid, but people like it when we disorient words to produce fancy names.

I designed a very quick website for the event using wordpress. It has been up at http://intesy.info for a while.

Now that the event is so close, life is really becoming hectic. We’ve just finished the reviews and intimated the selected people about their selection.

We’re working hard towards it, and I hope this year, its bigger and better than last year.

MediaWiki is good software, commanding a decent amount of respect among the FOSS community.

Nobody can ruin it better than these people: http://www.partimage.org/Main_Page

I wonder if partimage.org corrupted by Microsoft or something.

Shyam Shankar was the guy who introduced me to Rock music. He was one of my most favourite seniors at college, in his third year when I joined college. Only Third years and Final years are allowed individual rooms and can have their own computers at our hostels. He used to listen to bands like the Red Hot Chili Peppers, Nirvana and Linkin Park, but with his tiny speakers, they sounded like hell to me!

He always used to notice my annoyance and would let me hear Lucky Ali or some other soft music for some time, but would switch back to Rock soon. Maybe he thought by making me listen to it again and again, he could force rock into me. But he didn’t succeed then.

Only an year and a half back, I bought a really got pair of head phones and started listening to the Red Hot Chili Peppers. Soon after, I was listening to all sort of modern rock - Linkin Park, Creed, Lost Prophets, Cold Play, Avril Lavigne, Evanescence, U2, Greenday, Snow Patrol.

I was slowly starting to realize that I couldn’t stand pop anymore, which is exactly what Shyam had predicted. I used to really love pop when I was at school. Even during my first two years at college, I used to listen to a lot of The Corrs, Natalie Imbruglia, Spice Girls and others. But now, if I hear any western pop music, I’ll run as fast as I can from the place.

Then came the 90s bands like Nirvana and Pearl Jam. And eventually, I started listening to classic rock. Since then, there has been no turning back.

Right now, Led Zeppelin are my all time favorites, and then I have monthly favourites. There have been so many bands classic and metal bands I’d find really impressive for a while then lose interest and find a different band. There have been several bands like Guns n Roses, Rammstien and others. But Evanescence and Metallica have been exceptions, because I’ve listened to them for more than a month because of the ultra heavy voices of the singers. And Metallica’s guitars may be distorted, but still they’re melodic. I’m listening to Metallica even now. As I type this, Metallica’s Nothing Else Matters is playing. This song has become another of my all time favourites. And Metallica too. I love their music, but hate the way they look.

I’m not sure if Shyam has too much time for rock these days. His work is like that. I had promised to call him more than a month back, but I haven’t done yet. He must be mad. I’ll give him a few Metallica discs when I meet him next. That should do the trick.

There are very few authentic tests that certify us to be cool people. I happened to come across this link and I scored 67/100. That’s a decent score and I’m happy with it. Try it. It is really accurate! Click here to take the test.

I came across a really good DVD Rip tool for linux called OGMRip yesterday. It can encode DVDs to the H264 format, which is one of the best video compression formats right now. And this tool is particularly good because it ensures best quality by adjusting resolution automatically based on our bits/pixel requirement.

If you’re using Ubuntu, the easiest way to get it is from getdeb.net’s repository. Goto terminal and use the following commands:


$ sudo -s

# echo deb http://ubuntu.org.ua/ getdeb/ >> /etc/apt/sources.list

# apt-get update

# apt-get install ogmrip

You’re done now. Now you can start the program from Applications -> Sound & Video -> DVD Encoder OGMRip. The interface is very friendly, so you won’t have any trouble with it.

Happy Ripping!

Unlike most other linux distros, the PATH environment variable cannot be set in Ubuntu by adding an assignment statement in the ~/.bash_profile script. This has been annoying me for some time and I was trying different things until I eventually thought of googling for it. Here’s how it is done.
There is a file called /etc/environment. This is where you set the path variable. Goto terminal, type

$ sudo vim /etc/environment

to edit it.

Ubuntu is known for wandering away from conventions, but why did they have to change this? The /etc/environment file is ok, the ~/.bash_profile method doesn’t work anymore. That means, there is no standard startup script in Ubuntu except the System -> Preferences -> Sessions dialog. Nobody would want the terminal to lose its power. I hope the Ubuntu developers know what they’re doing.

We received the SBC9302 a week back. The box had the board, a serial cable, a cd with development software and manuals, and a voltage eliminator for the board.

Linux was pre-installed and all we had to do was to use the serial RS232 cable to connect the board to the computer, then use Minicom (or HyperTerminal in Windows) to boot the embedded OS and get a terminal from it. We tried it and it worked perfectly. We got a terminal and most Linux commands worked. And the entire installation was not bigger than 8MB!

Next job was to try downloading programs onto the board and execute them. But to do that, we have to create a new OS image that has our program and then download it to the board. Atleast that was what the manual said. We tried compiling the code, but we had quite a few problems with that. None of us has done this before.

That was when this idea struck me. The manual says that the OS automatically mounts USB storage devices connected to the board. So we could use a thumb drive to connect and transfer our binary to the board. We wrote a small PID controller that has a simulated process on the desktop, so that it would compile on the normal desktop gcc compiler.

To compile it with the arm-linux-gcc I thought we had to make some modifications to the code. And I didn’t have a clue about the modifications that we had to make. They had not included a programming manual in the cd they gave us. So I tried compiling the same code with the arm-linux-gcc hoping that the compiler would suggest modifications. But unbelievably, the code compiled without errors! Here’s the code:

#include <stdio.h>
#include <pthread.h>

#define KP 15 / 10
#define KI 5 / 10
#define KD 10 / 10

float pid_control(float target, float current)
{
     float error;
     float delta_err;
     float p_out;
     float i_out;
     float d_out;
     float output;

     static signed int integral_err;
     static signed int prev_err;

     error = target-current;
     delta_err = prev_err-error;
     integral_err += error;

     if(integral_err >  200)
           integral_err  = 200;
     if(integral_err <  -200)
           integral_err  = -200;

     p_out = error * KP;
     i_out = integral_err * KI;
     d_out = delta_err * KD;
     output = p_out + i_out + d_out;

     if(output > 127)
           output = 127;
     if(output < -128)
           output = -128;

     prev_err = error;
     return (float)output + 128;
}

int main(void)
{
	float CO;
	float current,target;

	printf("Enter set point : ");
	scanf("%f",&target);

	printf("Enter initial controller output : ");
	scanf("%f",&current);

	while(1)
	{ 

		CO=pid_control(target,current);
		system("clear");
		printf("CO = %.2f",CO);
	        current=current+(CO-127)/10;
		printf("   Current = %.2f\n",current);
		sleep(1);
	}
}

And after transfering it to the board using a thumb drive, the program ran just as it had on the desktop. Wow! I had been wondering how I was going to learn the entire ARM architecture in a month, and on seeing this, I was flying with joy. This would save me a whole lot of work!

Still there is a long way to go. We have to design interface hardware, write device drivers for them, and get them all to work to gether. Lets see how it goes.

This is the first of several articles that I’l over the next few months about developing Embedded Linux systems. Two of my friends and I have decided to make a Direct Digital Controller on an embedded linux SBC.

The first task for us was to acquire a development board. We approached Shreshta eTechnologies in Bangalore first. Though they had a board that would be perfect for us, they did not have the board in stock, and wanted atleast a month to get one for me. So we needed a different solution.

We searched again and landed up at SPJ Systems, Pune. After discussions we bought the SBC9302. Though we are having a few problems with it, the board rocks! Unbelievably powerful and has features enabling it to be used for a variety of highly complex applications.

Our application would be relatively simple. I’l post more later.