Are you blocking your way?

Recently I did a comparison between the present me, and the me 6 years back, when I was beginning as an Engineer. What I found is that the rate of progress that I made at that time is substantially larger than the one I am making now-a-days. I couldn’t find any external reason. The only possibility is that my own thoughts and believes are causing the drag.

Six years back, my attitude was like, ‘I have nothing I can be proud of; I have nothing to loose’. But these days it seems to me that I am too conscious about the way different people perceive me. This was too big a revelation to me. I felt that I am more complex than I ever imagined (One of my guiding philosophies is ‘Sense and Simplicity’. I always wanted me and thought myself to be simple.).

There is a feeling like ‘I have a reputation, and I don’t want to spoil it’ running in the sub-conscious. This I felt is the reason why I am more conscious about what people perceive me as, rather than what I really am. This is the same thing that is stopping me from doing many things (may a-little-bit-risky things). This precisely should be the system that is causing all the drag that I am experiencing.

So what’s the way forward?. Destroy this ‘ego’. More obscurely as ‘March in the path of self destruction’ (not ‘self-destruction’; the hyphen changes the whole meaning by 180 degree). Involve in things that can really hamper your public image, and let your image be gone. Fear of height comes when you look downwards. Make yourself believe that you have nothing to loose, no social reputation, and always look up. This is the way you can overcome the fear of height, even if you are at a height.

Do you know what the best condition a man can ever get? To have a bunch of people around, who doesn’t give you any respect. This I would call as ‘Impedence matched’. Some call as ‘wavelength matched’ or ‘same frequency’. This bunch of people will look at each other, and they grow together. There is minimal drag.

Thus I am in the path of a bit transformation. Don’t know if the mission will be scrapped before the completion. But anyways, it has already begun. Let me see if I can ‘Destroy the temple and rebuild it in three days’ (Well.., I think it will take me more than even three months – but lets not alter the beauty of that quote..).

Image under creative commons license – http://www.flickr.com/photos/carquinyol/6158405614/

Must use tools for Electronics/Electrical Students

Here is a list of computer based tools, which i know or have used and felt to be great and must-use for every elctrical/electronics engineering students. Priorities are price, ease of use on multiple platforms, popularity etc..

Analog/Power Electronic Circuts – LTspice (works smoothly in wine)
Antenna Design – MMANA-GAL
C/C++ IDE – Code::Blocks (linux & win versions available. use the installer with mingw, if you want compilers also installed)
Embedded Development – SDCC (8051), WinAvr (AVR)
Networking – WireShark (have both linux and win versions)
Numerical Simulations, Visualisation – Octave (great on linux, with QtOctave), Matlab (non free), Scilab. Scilab’s language is a bit different from the other two.

There are many other tools like KiCad that are worth giving a try. For digital circuit simulation, evaluation/student version of many softwares are available. In addition to these, I have used tools for PCB layout etc, which I don’t remember the name. sourceforge.net is a good place to search for authentic free softwares.

Acoustic Violin for Stage Performance – Acoustics Setup

Twice, I had bad experiences with audio system setup with acoustic violin on stage. The problem is not because of unavailability of technology, it is because of lack of people with knowledge behind the scene. Either the acoustic instruments won’t be audible or there will be wow/ringing(that low and high frequency sounds when you point a microphone towards the speaker and increase the gain). I am an amateur violinist, as well as an electronics engineer, with a lot of fascination towards acoustics. If you are going to be on stage with an acoustic instrument, these are my ideas (untested) to avoid or reduce the problems.

Monitors
Monitors are those on-stage speakers, pointing at the performer. Try to be as far from the monitor as possible. If possible, avoid monitors. Monitors were a source of great fascination for me, as, with my experiences with speakers and electret microphones, pointing a speaker to a microphone is always going to cause wow/ringing. Now I understand the trick is done by the directivity of the microphone assembly.

Microphone
Microphones used for stage performances are directional. Typical ones pickup sound from the front very well, and that from the rear very poorly. Position the microphones in such a way that all the monitors are at the back side of the microphone. The front should be pointing to the instrument, preferably the f-hole (This may be a myth, but it is commonly believed, that the sound from the violin comes out through the f-hole, and hence the most loud at that point). Unfortunately the f-hole of violin is in a place, where if a microphone is placed, can obstruct the bowing. This is thus up to the artist and his style of bowing. Also there is a chance of bad sound, as the sound as the resonances from the body and other part of the violin may be quite less intense than the resonance of the air cavity, compared to actual audience. In fact it is popularly known that the sound that is heard by the audience is far better than the one heard by the performer himself. The solution is to use a more directional microphone at a greater distance from the instrument. Advanced sound engineers can consider using array microphones to achieve very high directivity.

Equaliser
In a typical performance, the violin is tuned to work at greater than 100Hz and typically plays at >200Hz. So the extreme low sounds can be cut off at the equaliser. This will reduce the wow effect, as the higher frequencies are more directional, and will be avoided by the directional microphone. Also to reduce the bow rubbing noise, some of the higher frequencies can be attenuated. Too low high-frequency content will fade the ‘timbre’/'colour’ of the sound. So it is up to the trained ear of the sound engineer to decide the attenuation.

Loud Speakers
Ensure that all the speakers are pointing away from the stage. Any decently constructed stage will have mechanisms to prevent reflection of the Loud Speaker from the walls.

Piezo Pickup
These are sensors used to pickup the mechanical vibration of the body(typically bridge), and convert it to electrical signal. Typically, the signals hence obtained will be of a different timbre/colour than the actual violin sound, as it doesn’t pickup the acoustic resonance. If you use this, the violin can no longer be called as acoustic. You will have to use filters to shape the violins’ timbre to the one that is audible.

Automatic Hardware Configuration for Embedded Systems

Most of the time required in embedded systems development (atleast in case of hobby level projects) is in the configuration of the on chip peripherals of the microcontroller. The traditional approach is to look up in datasheets and then set associated register values for the desired functionality. This is very tiedious and time consuming. A better option is to define some of the frequently used configurations using some name indicative of functionality, and OR in different such values to generate the value for a single register. This is the option provided by common compilers like gcc.

A better way is to code small pieces of code, that will automatically configure the peripherals for a subset of the functionalities offered (believe me, it is difficult to programme for all the functionalities provided by the hardware using such a program). This piece of configuration code will be executed at the beginning only, so it will not impact the performance of the system other than consuming some extra flash code memory. Quite often startup time or flash memory is not a limitation, compared to RAM or CPU.

The process of creating such a code is very labour intensive. But once such an auto config code is created, most often, you can reuse the code as such, and sometimes with slight modifications, to incorporate extra functionality. This makes the development much faster. Code generators producing the configuration code, based on specifications are available for some of the platfroms like AVR. But such tools are not available for all existing and yet to be marketed hardware.

Examples

The following illustrate the three methods for configuring the Timer0 of Atmega32 to CTC operation at a frequency of 5kHz, when the IO clock is 8MHz. The compiler used is avr-gcc, which is available in the repositories of Ubuntu 11.04.

Crude Method

TIMSK|=0x03;    //Enable overfolw, and compare match interrupts
TCCR0=0x8a;    //Prescaler is divide by 8; timer mode....
OCR0=200;

Need to go through a datasheet to code and understand.

Formal Method

TIMSK|=(1<<OCIE0)|(1<<TOIE0);
TCCR0=(1<<FOC0)|(1<<WGM01)|0x01;
OCR0=200;

Still need to go through a datasheet to understand or code. But easier to understand than crude method

Proposed Method

initTimer0(5000,8000000,T0_TIMER,T0INT_COMP,0.5);

Only need to specify the requirements-Easy to understand, modify etc. Not as easy to code, as the real thing is behind the function call, as given below.

The function is defined in another file or library as,

//Timer modes
#define T0_PWM  0x68
//Fast_PWM mode, clear OC0 on compare match (up count)
#define T0_SYMPWM 0x60
//Phase correct PWM, clear OC0 on compare match during up count, and set during down count
#define T0_TIMER 0x88
//OC0 disconnected, CTC mode

//Timer interrupts
#define T0INT_ALL   0x03
#define T0INT_COMP  0x02
#define T0INT_OVRF  0x01
#define T0INT_NONE  0x00

void initTimer0(unsigned long frequency,unsigned long clkIO,unsigned char mode,unsigned char interrupt,float dutyCycle)
{
    unsigned char config, count;

    TIMSK=TIMSK|interrupt;

    if(frequency>=clkIO/256){
        config=mode|0x01;   //Prescaler divide by 1
        count=(unsigned char)(clkIO/frequency);
    }
    else if(frequency>=clkIO/(8*256)){
        config=mode|0x02;
        count=(unsigned char)(clkIO/(8*frequency));
    }
    else if(frequency>=clkIO/(64*256)){
        config=mode|0x03;
        count=(unsigned char)(clkIO/(64*frequency));
    }
    else if(frequency>=clkIO/((long)256*256)){
        config=mode|0x04;
        count=(unsigned char)(clkIO/(256*frequency));
    }
    else{
        config=mode|0x05;
        count=(unsigned char)(clkIO/(1024*frequency));
    }
    TCCR0=config;
    if(mode==T0_TIMER)
        OCR0=count;
    else
        OCR0=(unsigned char)(dutyCycle*255);
}

Install Firefox 4 on Ubuntu

Firefox 4 is catching on. Still Ubuntu has not put this in its stable repositories, for the older versions. Newbies in Ubuntu will find installing Firefox 4 difficult. This describes the method I used to install Firefox 4.

First download Firefox 4 from the official site. The downloaded file will be an archive named firefox-4.0.1.tar.bz2. Extract the archive file by right click and extract here. A folder firefox will be created. Inside this folder, a file firefox is present. Give execute permission to this file by typing sudo a+x firefox/firefox.

Double clicking the file will open a message box. Choose Run in the message box. This will open the Firefox 4.0 browser. This is the simple way of using Firefox 4.

A neater way is to move the folder firefox either to a separate folder for programs in your home folder, or to the /usr/local/ directory. For the former, running the firefox file inside the firefox folder is enough. Moving the folder to /usr/local will require root’s permissions. Type sudo mv firefox /usr/local to move the folder to /usr/local/

The older version can be removed using synaptic, which leads to a broken application launcher in the top panel. Right click on it, and choose properties, browse for the firefox file or enter its path correctly. The command that I have to use will hence be usr/local/firefox/firefox %u, as I have moved the folder firefox to /usr/local Click on the icon on the left choose firefox/icons/mozicon128.png. Click on the launcher to launch Firefox 4.0

Brand and Quality

Premium brands are believed as symbol of quality, and price to be proportional to durability by many a people of the modern world. Rarely do people think as to how much their belief is correct. I tried to question the believes of a few people, who strongly believed brand means quality. Their main argument is the durability. But when the question of whether it is wise to pay four times to get twice the durability, many fall silent.

The Indian middle class is very much interested in durability of whatever they buy. Sometimes the durability expectations will be even double the expected use period of it. Indeed there was a time when I was a child, when Indian brands were symbols of quality, and they were actually delivering the quality and durability. When the international brands came in, though all those rules changed, still people have the perception, that the more expensive something is, the better it is.

Some brands tries to forcefully sell their products even when the consumer don’t really want it. Some operating systems are bundled with every laptop, and people are forced to choose that. In fact, many people have a limited choice of hardware, once they decide not to have that operating system, sponsored by some monopolies.

Another trend, is the selling of food at unreasonably high price, even when no value addition is done. Many people will have the experience of getting into a hotel, and forced to take some bad tasting food from there, and pay a huge bill. In my view, it is better to leave the hotel, after seeing the menu, if you are not satisfied, even if you have to burn the same amount worth of petrol to get to a more satisfying place. Such shops should fall victim of the market forces and competition. Such shops are successful at city like areas, where there is a high chance of new people coming in every day. If you take the food today, feeling unsatisfied, somebody else will do that tomorrow, though you wont go there again.

Why are there artificial distinctions being imposed for the software? Like different versions of Operating systems, one for business, one for Home etc., with different price points and features, when the company will have less expense, if they have a single version of the product, with single pricing?. It seems the motive is to give people a feeling of choice and freedom to choose, so that they will not exercise, the instinct for freedom, to choose something they don’t sell. People wants to be free to choose. The success of business it seems in maintaining a monopoly and giving artificial choices to the consumers.

When will there be an end to all these and more bad practices in the market? May be on that day that never comes, when all the people on the earth are fully aware of the market!!!

Staging of Harmonica

Yesterday was the farewell function organised by Tech Keralites, at SN Bose auditorium. I wanted to have a staging of whatever harmonica (mouth organ) I have learned, in a Tech Keralites’ stage. I didn’t play at for the New year celebration, as I was not prepared enough. Tech Keralites’ stage, for me, is a bit less formal, and hence chance of being nervous is quite low. In SN Bose, there is less of a problem with ringing of audio, as they use lot of small speakers on the roof above the audience, to distribute the audio, and there are no monitors. Only concern is that the speakers being very small, will produce the bass notes or not.

Everybody passing out this year was sharing some experience in campus and giving some kind of performance. As my turn came closer and closer, I began to feel my mouth to be too dry — a bad condition for mouth organ playing — the instrument will not slide smoothly on the lips. I went out and poured a bit of water on the harmonica, and came back. When my turn came, I went to the stage, with the harmonica and the notes, not much nervous. A short talk about the motivation in 10-20 words, giving the notion of me wanting to play the harmonica on stage. It turned out that as my friends have already informed, they have scheduled my performance to be by the end of the programme. As I was prepared for two songs, I decided to play one at that time and the other later. Played the Hindi song Piyu Bole… The audience were quite cooperative, probably because a majority was from MMM (my own hostel).

For the next performance I was called to the stage. This time also, not much nervous, I went to stage, and played the Titanic movie song. This one was special for me, in that I have made out the notes on my own by listening to the music. For both the songs, only the notes were in paper. The rhythm was only in my mind. As I have proved many times earlier with violin, that I’m not that good with rhythms, I don’t know how this was….