tag:blogger.com,1999:blog-11810655889272466342024-02-21T09:55:15.647-08:00Something in ComputerScience I have worked with/Working onThis blog is dedicated to my reading on computer science. This typically involve surveys I have done to understand certain areas especially in networking.
Though I try to keep it correct to the best of my knowledge, I request the reader to verify himself/herself the same.
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In six months more than 5000 visits for tinyos and sensor networks. Thanks for the support
GireeshGireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.comBlogger23125tag:blogger.com,1999:blog-1181065588927246634.post-88137217914495564462015-01-17T22:06:00.000-08:002015-01-17T22:06:02.100-08:00Detecting the Toy Car with OpenCVOpenCV is a wonderful library with a lot of options on image processing. The simplest way to detect an object is by color. Color range can be in RGB/HSV/YUV. Algorithms for filtering work well with HSV.
Find lower and upper ranges of HSV values
Filter using color and find mask-color
Optional: Filter using backgroundSubtractorMog2-> mask object movement AND both the masks
Use erode, dilateGireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com0tag:blogger.com,1999:blog-1181065588927246634.post-6370775841336053002015-01-09T08:17:00.001-08:002015-01-09T08:17:09.396-08:00Back to the toy car: My experiments with Raspberry PI
What can I do with Raspberry PI?
It is a B+ model. To use it as a fan-less credit-card computer and do browsing? Nah.. it sucks. Too slow to respond. To connect to TV and make it "smart"?
Oh wow... Well, within a week of getting one; I have configured it to run Raspbmc (now KODI). It happily stated serving as my media manager.
I thought about the experiment I did for the OpenHouse event. Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com1tag:blogger.com,1999:blog-1181065588927246634.post-53437767529324333192014-06-26T23:32:00.000-07:002014-06-27T17:17:24.475-07:00The lambda calculus and nirvanaIt is pretty interesting to see things evolve in time. Especially in Computer Science, where people have a (mis)-concept that everything here has a short "half-life".
I really did not believe so. I actually loved the "Science" part of Computer Science as much as I love the "engineering" part of it.
I do not know why and how did I miss such a wonderful thing as pure programming language (even if Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com0tag:blogger.com,1999:blog-1181065588927246634.post-56822949682469715912012-02-19T08:23:00.001-08:002012-03-27T23:26:59.332-07:00Presentation SlidesI felt, there may be people who may be interested in the summary of work our Team has done at IIT Madras on Wireless Sensor Network Testbeds (for monitoring applications and for target tracking)Testbed Design: From COTS to Open Hardware (SRM: 2012)NCC 2012 : Testbed Based Throughput Analysis in a Wireless Sensor NetworkIFIP Wireless Days 2011: A Testbed for Distributed Target Trackingwith Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com0tag:blogger.com,1999:blog-1181065588927246634.post-68465542808946945812011-10-27T09:09:00.000-07:002011-10-28T09:09:10.199-07:00Omnet++ Lessons Part OneOmnet++ is one simulator which I liked a lot. It gave me enough confidence that I can build a network from scratch (like Steven's book building a complete TCP/IP stack). These files were written while I was at IIT Madras and reproduced here for learning purpose.In this post, I start with a packet generator which simply generate a packet per given period of time.This will introduce minimum number Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com3tag:blogger.com,1999:blog-1181065588927246634.post-65274766411135686312011-10-05T18:39:00.000-07:002011-10-11T09:16:56.555-07:00Gentle introduction to researchAbout three and a half years back, when I was joining MS by research in IIT Madras, I did not have much idea about how to do it or what to look for or what could be the outcome. This blog is about the methods I learned over the years from my guides and colleagues on research. Please note that it is for people who are just starting research or thinking of doing research. Before I begin, a Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com7tag:blogger.com,1999:blog-1181065588927246634.post-53170099663881892042010-11-25T00:39:00.000-08:002010-11-25T00:42:41.767-08:00Rethinking the assumptions about sensor model in WSN literatureThis is an extract from the first draft of the thesis I am working on.Please read it if you are sincerely working in Wireless Sensor Networks.Oxford English dictionary defines sensor as ”a device which detects or measures a physical property and records, indicates, or otherwise responds to it”. A better definition from Wikipedia is ”a device that measures a physical quantity and converts it intoGireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com6tag:blogger.com,1999:blog-1181065588927246634.post-31035435424306796242010-03-28T22:33:00.001-07:002010-03-29T23:18:36.514-07:00File Transfer (peer to peer) using two motesAfter receiving requests from so many people, I thought of writing this simple application which can transfer file between two computersAssumptions:Environment used is: TinyOS 2.1.0 with UbuntuKnowledge to compile "BaseStation" application (coming with TinyOS) with a modification in Makefile : CFLAGS += - TOSH_DATA_LENGTHBasic understanding of file operations in JavaNo other nodes are in the Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com15tag:blogger.com,1999:blog-1181065588927246634.post-53056795988249260552009-10-13T02:35:00.000-07:002009-10-13T03:02:04.555-07:00ZigBee/802.15.4 SnifferThis is a simple ZigBee sniffer application which can dump raw data from any zigbee transmitter in 2.4 GHz and will work in the default channel set while compiling. The purpose is to demonstrate how to use sniffers.Platform tested MicaZ and TelosB ( Should work with Imote also)Interfaces neededBoot : To boot up the deviceLeds : To indicate data captureReceive : To capture the packet (provided Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com6tag:blogger.com,1999:blog-1181065588927246634.post-43837237586734026302009-04-07T21:05:00.000-07:002009-04-07T22:28:21.848-07:00Debugging NesC made easy with Printf libraryPut watch , breakpoints ... all sort of such powerful debugging we miss when we do tinyos and nesc. I had a good struggle to find out what went wrong in a code till I figured out serialforwarder and the libraries to print values in between. This again needs many routine calls and stuffs. To make things easier, there is a library "tinyos printf". Anyone who had used printf in C, same Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com5tag:blogger.com,1999:blog-1181065588927246634.post-71167652172170642152008-12-08T22:00:00.000-08:002008-12-08T22:19:46.976-08:00Simple One Dimensional Routing in TinyOS 2.x /2.10Program listing: Routing in one dimensionOS: TinyOS 2.10/ TinyOS 2.xTools used : noneAssumptions: You are able to understand BlinkToRadio example from Tinyos tutorials.Concept used: TX_POWER is set when sending a data to do multiple node transmission in a small room testbed. ( If you want to use it, you need to include the following in the AppCcomponents CC2420PacketC;App.CC2420Packet->Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com11tag:blogger.com,1999:blog-1181065588927246634.post-34565731879389202912008-11-25T22:08:00.000-08:002008-11-26T20:38:30.893-08:00Hands on experiments with micaz, MTS310 and MIB520This post is after the first set of trials with micaz mote. Till now worked only with telosb, which has usb interface and programming in single board including sensors on board.This experiment is not conducted in avrora or any emulator.Mote used- Micaz- CC2420 Radio (Zig-Bee compliant) : The range was much better than Telosb. It gave 21metres compared to 8 metres in telosb.Following image shows Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com8tag:blogger.com,1999:blog-1181065588927246634.post-7834535187045460462008-11-20T22:04:00.000-08:002008-11-20T22:33:40.419-08:00Tracking Using RSSI: application in tinyos2.10+ubuntu+javaThis small project was done as part of our OpenHouse event during Tech Fest Shaastra2008 atIIT Madras. It's the first application of its kind I have written.Please read my previous posts to understand basics, if you are not familiar with basic termsProject : Target tracking using RSSI with TelosBTypes of nodes: Mobile node, Static nodes and base stationTools: Java serialforwarder and customized Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com111tag:blogger.com,1999:blog-1181065588927246634.post-60798061660906373052008-10-25T02:20:00.000-07:002008-10-25T10:33:17.099-07:00Using SerialForwarder Interface of TinyOS with AvroraDear reader,Special thanks for the feedback and comments. Please continue supporting this small effort of mine to tinyos community.As I promised in last post, here is the first step to analyze the RSSI values from a mote. In order to understand concept of base station and how things are done in real world, the following tutorial may help you.As usual, sample code is provided at the endAssumptionsGireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com23tag:blogger.com,1999:blog-1181065588927246634.post-83796753943571837182008-10-13T21:48:00.000-07:002008-10-25T10:29:33.057-07:00Radio Communication Simplified Using TOSTHREADSDear reader, Welcome back again with another post on tosthreads or cthreads in TinyOS. As usual my assumption is that you have followed up to my last post on cthreads. If not, it's beter to do it now before continuing!!! If you have visited tinyos wiki, you may wonder how complex the radio communication code for BlinkToRadio. All that we are trying is to send a simple msg and it needs lot of Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com3tag:blogger.com,1999:blog-1181065588927246634.post-91955249086598106412008-09-17T20:45:00.000-07:002008-09-17T21:37:49.280-07:00Working with motes using TOSTHREADS... An easier way to do TinyOS programmingDear reader, Thanks a lot for responses and comments to make my small efforts on TinyOS programming a success. So here is another good news for C programmers who wants to work on TinyOS. No more NesC codes and hurdles of it.TinyOS 2.10 comes with integrated library for tinythreads. The library examples can be found in "/opt/tinyos-2.1.0/apps/tosthreads" for a default installation.The Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com9tag:blogger.com,1999:blog-1181065588927246634.post-19738077007858974662008-09-17T10:22:00.000-07:002008-09-17T10:46:54.746-07:00Running BlinkToRadio using AvroraDear reader, So it's time to test something more interesting. Here I assume that you have already installed tinyos2.10 and Avrora using my previous posts and you have gone through the TinyOS wiki about BlinkToRadio. The tinyos install directory contains app/tutorials folder where you can find implemented code of all these programs.I am not explaing the code, but just try to demonstrate how Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com5tag:blogger.com,1999:blog-1181065588927246634.post-14181421646298076752008-09-10T23:01:00.000-07:002008-09-17T22:08:27.236-07:00Running TinyOS programs using AvroraAvroraThe readers may be wondering, the post for installation of TinyOS does not have TOSSIM installation steps. It's because I have found Avrora emulator more easier than TOSSIM scripts. Avrora is emulator/simulator for wireless sensor networks, written in Java by UCLA group. It takes an object dump of tinyos programs over AVR platforms ( mica2/micaz) and is capable of single node emulation for Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com65tag:blogger.com,1999:blog-1181065588927246634.post-3485558222292415812008-08-30T23:16:00.000-07:002010-09-20T00:58:09.677-07:00Installation of TinyOS in Ubuntu- @page { size: 21.59cm 27.94cm; margin: 2cm } P { margin-bottom: 0.21cm } --> TinyOS is becoming the defacto standard OS for sensor network platforms and Ubuntu is most popular distro in Linux flavours. The follwing steps helps to install the TinyOS environment and compile and run the programs.After everything is done, download this skelton code and verify the installationUPDATED FOR Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com130tag:blogger.com,1999:blog-1181065588927246634.post-30268157084538450832008-07-06T17:51:00.000-07:002008-12-10T08:22:42.449-08:00Introduction to Wireless Sensor NetworksWhat are sensor networks?Sensor networks consist of many - up to several thousand - small distributed computing devices that sense and interact with the environment. Various sensors allow a sensor node to measuretemperature, sound, vibration, pressure, motion or pollution. Their low price and low energyensures that sensor networks can be deployed in large numbers. A sensor node consists of a Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com9tag:blogger.com,1999:blog-1181065588927246634.post-44810227317739069272008-06-29T00:43:00.000-07:002008-12-10T08:22:42.705-08:00Security in Wireless Sensor NetworksSecurity in Sensor NetworksIntroductionWireless Sensor Networks are expected to be a solution to applications. Two categories of applications are monitoring and tracking. This include industrial/health/millitary applications which are mission critical and often handle sesitive data. But because of the peculiar nature of network, the traditional security mechanisms are often can not be applied to Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com2tag:blogger.com,1999:blog-1181065588927246634.post-65898261026304743722008-02-08T05:16:00.000-08:002008-02-08T05:22:14.550-08:00Review on Rethinking the Internet Design by KahnThe article by David Clark on rethinking the design of internet analyses the original design goals v/s the current scenario of internet. The internet was designed to be based on end-to-end system with intelligence in hosts which communicates and not rely on the underlying architecture of communication. Thus it’s responsibility of the users/system at end to check for validity of data/information, Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com0tag:blogger.com,1999:blog-1181065588927246634.post-28004428697200875082008-02-08T05:02:00.000-08:002008-02-08T05:19:28.173-08:00Good morning/afternoon/evening dear reader For many years we have seen the growth of internet and its good and bad use. This article is not commenting on that, but on the paper "The Design Philosophy of the DARPA Internet Protocols" David D. Clark* SIGCOMM ‘88.I did this as a part of my course work, but felt to make it available for others also. Feel free to comment on my review, so that I Gireesanhttp://www.blogger.com/profile/15328543844556137365noreply@blogger.com0