Friday, 6 January 2012

MICROCONTROLLERS

The morning sessiuon was handled by Bejoy sir, on microcontrollers.


A microcontroller (sometimes abbreviated µC) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals.It is designed to carry on a particular function where as a microprocessor is for a general purpose.Before inputting something care should be taken that  a 1 should be given to the D flipflop to make the transistor in the OFF state.


DELAY GENERATION
There are two methods for delay generation which are:

  1. LOOP Technique.
  2. Using Timer.
LOOP TECHNIQUE: This is very simple software based delay technique. In this method we load a number in a RAM location and decrement it till it becomes Zero.

USING TIMER: Many times we require precise internal time delays between two actions this can be accomplished using software techniques like Loop Technique but these delays keep the processor occupied because of which other important functions cannot be done. To relieve the processor of this burden we can use TIMERS provided by the controller. 8051 has two internal timers T0 and T1.

The timers count increments by every MACHINE CYCLE. A single Machine Cycle consists of 12 crystal pulses. i.e.
1 MACHINE CYCLE = Crystal Time/12.
Crystal Time = 1/Crystal Frequency.
So if we use 12MHz crystal then the timer will increment by 1 in every 1µS. The Timer always COUNTS UP, doesn’t matter in which mode it is being used the timer value is always incremented


INTERRUPT AND POLLING:

In a computer, a polled interrupt is that which notifies the part of the computer containing the I/O interface that a device is ready to be read or otherwise handled but does not indicate which device. The interrupt controller must poll (send a signal out to) each device to determine which one made the request.


An interrupt is considered to be an emergency signal that may be serviced. The Microprocessor may respond to it as soon as possibleIt is of two types:
1.VECTORED: The address of the subroutine is already known to the Microprocessor.
2.-NON VECTORED: The device will have to supply the address of the subroutine to the Microprocessor.


What happens when MP is interrupted ?
When the Microprocessor receives an interrupt signal, it suspends the currently executing program and jumps to an Interrupt Service Routine (ISR) to respond to the incoming interrupt. Each interrupt will most probably have its own ISR.ISR is an interrupt service routine is a software routine that hardware invokes in response to an interrupt. ISRs examine an interrupt and determine how to handle it.


SERAIL AND PARALLEL COMMUNICATION:
Serial communication is the process of sending data one bit at a time, sequentially, over a channel or computer bus.
Parallel communication is a method of sending several data signals simultaneously over several parallel channels. 

A Frame is a digital data transmission unit or data packet that includes a sequence of bits or symbols making it possible for the receiver to detect the beginning and end of the packet in the stream of symbols or bits. 
Asynchronous transmission uses start and stop bits to signify the beginning bit.Synchronous transmission uses no start and stop bits, but instead synchronizes transmission speeds at both the receiving and sending end of the transmission using clock.Simplex communication refers to communication that occurs in one direction only(radio).A half-duplex (HDX) system provides communication in both directions, but only one direction at a time (not simultaneously,"walkie-talkie").A Duplex communication system is a point-to-point system composed of two connected parties or devices that can communicate with one another in both directions simultaneously. An example of a duplex device is a telephone.

The second sesion was on the practical use of what we studied in the morning.We were divided into two groups consisting of four members each and the design and programming using arduino  duemilanove  was explained.The lighting of an LED with and without a push button switch was performed.

The Arduino Duemilanove ("2009") is a microcontroller board based on the ATmega168  or ATmega328 . It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.
"Duemilanove" means 2009 in Italian and is named after the year of its release.
  
Arduino hardware is programmed using a Wiring-based language (syntax and libraries), similar to C++ with some simplifications and modifications, and a Processing-based integrated development environment.


 

Wednesday, 4 January 2012

!MUCH RELAXED DAY!

           The session was scheduled at 9 in the morning but delayed due to  some reasons.The morning session left us free without any work as a part of the group went to the lab to  get  a review of the experiments.The time was spent by  browsing the net,posting news on the HPC blog.Suddenly I thought of my laptop and went to the hostel to get it  to  fix the wireless network  connection.I took the help of my team mates to  delete the windows but we could not proceeed due some technical problems.Then sir instructed us to reinstallthe entire thing,but we could not complete the task.

          The afternoon session cannot be called as a class but it was much more like an interactive session.We were given an idea about the free software and the importance of source code.The wikipedia defines Free Software as-Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients have the same rights under which it was obtained and that manufacturers of consumer products incorporating free software provide the software as source code.

          Next we were introduced to linear regression problem,the approach to find the optimum solution and were asked to do the program in octave to find the values of constants and the guess value.As i browsed through the net I could gel the direct formula anh with the help of a few for loops the task could be easily performed.

          In statistics, linear regression is an approach to modeling the relationship between a scalar variable y and one or more explanatory variables denoted X. A linear regression line has an equation of the form Y = a + bX, where X is the explanatory variable and Y is the dependent variable. The slope of the line is b, and a is the intercept (the value of y when x = 0).
The best fit line associated with the n points (x1, y1), (x2, y2), . . . , (xn, yn) has the form
    y = mx + b
where
    slope = m=


    n(xy) - (x)(y)

    n(x2) - (x)2
    intercept = b=


    y - m(x)

    n
Here, means "the sum of." Thus
    xy = sum of products = x1y1 + x2y2 + . . . + xnyn x = sum of x-values = x1 + x2 + . . . + xn y = sum of y-values = y1 + y2 + . . . + yn x2 = sum of squares of x-values = x12 + x22+ . . . + xn2
         

Tuesday, 3 January 2012

THE FIRST CLASS OF 2012!

                                     !happy new year!
The first class of 2012 started around 9.00 am.We were asked about the TED videos we watched and how we spend the vacation.Initially  through an demonstration we were given the task of installing octave in all the systems in the L3 lab.After completing the task we were asked to write a program to do selection sort on the numbers defined.I could do it well with the small assistance from one of my team mates.


Around 1 we were asked to find the time that would be taken for sorting numbers with ranges 10,100,1000,10000 and 100000 and to plot the graph between the time taken and number of variables sorted.Next we were given the task of preparing a presentation for 10 minutes about any topic with a maximum of 20 slides.My team chose the topic magic square-what exactly it is,how to  construct an even order(multiples of four) and an odd order magic square.
magic square of order n is an arrangement of n2 numbers, usually distinct integers, in a square, such that the n numbers in all rows, all columns, and both diagonals sum to the same constant.


The topic was new to me but it was a very simple topic and easy to understand.We were able to complete the task by 3 and all the groups were gave the presentations in front of Mahesh sir,Unnikartha sir and Bejoy sir.We got good comments and everyone was given tips to improve.


The day concluded with the birthdaty celebration of Vivek sharing the sweetness of the birthday for the first time among the HPC members!

Monday, 2 January 2012

DIGITAL CHIPS!

Digital Electronics devices are usually in a chip format.
The chip is identified with a part number or a model number.
A standard series starts with numbers 74, 4, or 14:
                       7404 is an inverter
            7408 is an AND
                              7432 is an OR
                              4011B is a NAND


     Basic logic chips often come in 14-pin packages.
     Package sizes and styles vary.
     Pin 1 is indicated with a dot or half-circle
   Numbers are read counter-clockwise from pin 1
     Chips require a voltage to function
     Vcc is equal to 5 volts and is typically pin 14
     Ground is typically pin 7


The voltage and ground pins must be connected for the device to function.

Chips – Specification Sheet

Wiring a chip



FEW MORE TED TALKS!



Eric Giler demos wireless electricity


http://www.ted.com/talks/lang/en/eric_giler_demos_wireless_electricity.html

It deals with the concept of resonant energy transfer.The experiment is to take a coil and make it
resonate at alternating current frequency and if another device is bought close to the first,they'll be strongly coupled and transfer magnetic energy between them.The aim is to start with electricity,convert it into magnetic field,take the magnetic field and convert back to electricity and then use it.


Henry Markram builds a brain in a supercomputert


Henry Markram is director of Blue Brain, a supercomputing project that can model components of the mammalian brain 

to precise cellular detail -- and simulate their activity in 3D. The aim is to build a detailed,realistic computer model of human 

brain.

Friday, 30 December 2011

more TED TALKS!!!


Lee Hotz: Inside an Antarctic time machine

http://www.ted.com/talks/lang/en/lee_hotz_inside_an_antarctic_time_machine.html


Its about antartica-the highest,riest,coldest and windiest region of the world and the scientists are drilling into the past of our planet to find the clues to the future of climate change.To study the effect of the global warming on the natural climatic patterns-winds,ocean currents,cloud formation etc.They started drilling the ice and found it to be a perfect time machine-they found a 10-foot long cylinder of compressed ice crystals that contain the unsullied air and trace chemicals laid down by snow,season after season for thousands of years.Studying the various layers of ice helps us to estimate the prevailing conditions at hat time and helps us to study the changes that have occurred during the past few thousand years.



David Hanson: Robots that "show emotion"


Its about robots that can see faces,make eye contact with you,make a full range of facial expressions,understand speeches and begin to model how you are feeling and who you are and build a relationship with you.They mainly aim at two things-one the perception of people and two the natural form of the interface,so that its more intuitive for us to interact with the robot and we start believe that its alive and aware.

Mike Biddle: We can recycle plastic


Less than 10% of plastic trash is recycled -- compared to almost 90% of metals --
 because of the massively complicated problem of finding and sorting the different kinds. Frustrated by this waste, Mike Biddle has developed a cheap and incredibly energy efficient plant that can, and does, recycle any kind of plastic.They recover materials from the waste and then recycle the end-of-life-stuff.The process start with metal recyclers which the stuff into very small bits and the shreddder residue predominently plastic is left behind.The materials other than plastic is taken outand sieved using magnets or air classification.Next the plastic is taken to multi step seperation process and the end result is the new plastic with redifined characteristics.  


Thursday, 29 December 2011

TED TALKS


TED (Technology Entertainment and Design) is a global set of conferences owned by the private non-profit Sapling Foundation, formed to disseminate "ideas worth spreading".
TED was founded in 1984[1] as a one-off event and the conference was held annually from 1990 in Monterey, California.[4] TED's early emphasis was largely technology and design, consistent with a Silicon Valley center of gravity. The events are now held in Long Beach and Palm Springs in the U.S. and in Europe and Asia, offering live streaming of the talks. They address an increasingly wide range of topics within the research and practice of science and culture. The speakers are given a maximum of 18 minutes to present their ideas in the most innovative and engaging ways they can. 
Though i have been watching the TED talks for the past two days,thought of writing about them came to me only today!The first one is about Gaming.Its by Ali Carr-Chellman and is on "Gaming to re-engage boys in learning".
http://www.ted.com/talks/lang/en/ali_carr_chellman_gaming_to_re_engage_boys_in_learning.html
 Ali Carr-Chellman pinpoints three reasons boys are tuning out of school in droves, and lays out her bold plan to re-engage them: bringing their culture into the classroom, with new rules that let boys be boys, and video games that teach as well as entertain.She argues that when compared to girls the boys suffer from Attention Deficit Hyperactive disorder bu nearly four times.She displayed many statistics comparing the number of boys and girls as school droupouts,expelled from schools etc and the boys were ahead of the girls in such statistics.


The seond one is on self aware robots-which have the ability to learn, understand themselves and even self-replicate.
http://www.ted.com/talks/lang/en/hod_lipson_builds_self_aware_robots.html
The talk was by Hod Lipson.Te robots have been performing a number of tasks like cooking,cleaning,washing and even shopping.He expands the function of robots into various other spheres too.It has four legs around the body which help in its locomotion,eight motors-four on the knees and four on the hips.It has also two tilt centres that tell the machine which way its tilting.These robots are of corse not very useful in themselves,but they might teach us something about how we can build better robots.


The third was by Larry Burns on the future of cars.
http://www.ted.com/talks/lang/en/reinventing_the_car.html
Its about sleek, customizable (and computer-enhanced) vehicles that run clean on hydrogen -- and pump energy back into the electrical grid when they're idle.In order to obtain something  very affordable,they took he advantage of Moores law  with electronic controls and software and they selected hydrogen as the engine carrier.They had Autonomy drivable with Hy-Wire which is the worlds first drivable fuel cell and the hydrogen and the fuel cell provide the opportunity touse the cars and trucks to generte the power for the grid