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Tuesday, December 30, 2008

A novel photo sharing experience with CEIVA digital photo frame

A novel photo sharing experience with CEIVA digital photo frame
Sharing our photos with friends and family will always be an exciting experience. Normally we love photos with frames of different styles which changes the look of photos more lively experience. There are number of digital photo frames available online. But I would like to elaborate a novel digital photo frame which I recently accessed through net. Yes, it is CEIVA Digital Photo Frame. The simple thing we have to do is creating a Picture plan membership with CEIVA, then the CEIVA frame will automatically display new photos received from friends and family located anywhere in the world.

Its features are unique when comparing with other photo frames. I would like to enumerate its photo sharing experience with respect to its way of display with all sort of communities with its personal touch and fully secured features.
We can share our photos with a single click. By creating groups of friends and family members, then we can invite our loved once to receive or send photos directly to the digital frame. The new photos can be received or send via email or camera phones. In addition to this, photos can also be received via Wi-fi, i.e. without having to connect with computer.
Photos tell the stories of our life. Now we can share those cherished memories in our own style by personalizing our photos with the following features.
• Add decorative borders and special messages
• Send customized photo greetings and holiday cards
• Add weather, news, sports, horoscopes and dozens of other channels — all delivered daily
As our photos are priceless, with its built in security, we can securely share photos with a circle of friends and family through a private network of frames. Its features are
• If it breaks, we fix it for free (customer pays return postage)
• Automatic and ongoing software upgrades
• Constant virus protection updates and spam filtration technology
• Live, U.S.-based customer service
The subscription with Picture plan can be monthly or annually with its least subscription fees. CEIVA digital photo frame gives really a magic experience with our photos.

Post?slot_id=30195&url=http%3a%2f%2fsocialspark

Saturday, December 27, 2008

Real time operating systems (RTOS) concepts and applications

Real time operating systems (RTOS) concepts and applications

In most of the electronics system, the operating systems used are RTOS. For understanding RTOS, it is required to know Embedded systems, Real Time systems, Need for OS in embedded and so on. Recent days the engineering projects are done on Embedded systems. So it is mandatory to know about Real time operating systems. I would like to share some of the important RTOS concepts here.

Embedded systems
There are many definition for describing the embedded systems. One among them is
“ Customized computer hidden inside a system to perform a specific task, but not itself a computer on it’s own “. Otherwise simply it can be defined as a computer on a single chip.

What is a real-time system?
Zero Processing time

Definition
The times by which tasks will execute can be predicted deterministically on the basis of knowledge about the system’s hardware and software

Real Time Systems

• As you may have noticed, most embedded components operate under real-time constraints – in industry, the terms embedded and real-time computing are used interchangeably
• The real-time computing domain is continuously expanding to support automation and vertically integrating enterprises in industry, telecommunications, public services and consumer devices

Some of the examples of Real time systems are
A web server, A word processor, An audio/video media center, A microwave oven, A chess computer

Real-Time Systems can be with time constraints which can be of soft or hard

• In soft real-time systems, missed responses are undesirable, but do not result in complete failure (e.g.video decoder, network switch)
• In hard real-time systems, failure to meet constraints results in complete system failure and is, therefore, an unacceptable condition (e.g. air traffic controllers,missile guidance systems or health monitoring systems where a missed response can have catastrophic consequences)

Need for OS
• We have seen that we can write program code for a microcontroller to enable it to perform various control and/or monitoring functions, e.g. a washing machine control system, without any operating system
• So, what is an operating system and why would one be needed for a microcontroller system?
Operating Systems

• The most basic feature, common to all operating systems, is support for multitasking, on top of this support could be added for networking, peripheral interfacing, etc. as required
• An operating system such as MS Windows has a complete graphical user interface and sophisticated functions for printing, disk handling, networking, etc.
Embedded OS
• Maybe an embedded microcontroller system does not require all of these, but it may need some of them
• The types of operating systems used in real time embedded systems, which often have only the fundamental function of support for multitasking. These operating systems may vary in size from as little as 300 bytes to 10Kb, so they are small enough to fit inside on-chip ROMs

Why Multitasking ?
• Embedded systems usually have access to only one processor, which serves many input and output paths
• Any concurrency must, therefore, be simulated and logical (rather than physical)
• Real-time systems must divide time between various activities in such a way that all the time deadlines (constraints) are met
Multitasking Advantages
• Activities / events occur concurrently (simultaneously) in the real world. Through multitasking, multiple applications can be logically modeled as task activities
• Better computing resource usage as multiple task execution can be interleaved on a single processor (rather than having a separate processor dedicated to each task)
Disadvantages
• Specific task execution time and sequence is usually non-deterministic due to interleaving (complicates timing problem)
• Debugging process is complex and difficult

Real-Time OS
Real-time operating systems (RTOS) will always include the following features:
• Support for multiple tasks running concurrently
• A scheduler to determine which task should run at any point
• Ability for the scheduler to preempt a running task
• Ability for external events to preempt a task
• Support for inter-task communications – synchronization and communication constructs

Real-Time OS Basics
The OS divides time into execution units called system ticks, at every system tick the scheduler is run and it decides which task should run next. A task is allowed to run for the duration of a system tick unless it is preempted by a higher priority task or it gets suspended

Some RTOS terminology:
• The term kernel is used to refer to the operating system component which provides core system functionality
• A task is an entity maintained and run by the operating system as an independent thread of execution
• There are normally multiple tasks running in a system, the kernel data structure used to monitor, control, and schedule execution of these tasks is referred to as the scheduler (or task control block)
• A task can be in any one of three states, pending, ready or running

Task Context Switching
• In multitasking systems a mechanism is needed for switching the processing context from one task to another, this is achieved by storing the currently running task’s state in kernel data and then loading the ready task’s state, thereby changing the context
• Consider a system with two task threads, A and B, when task B is running the stack pointer and program counter are set for task B’s context
• Upon a context switch to task A from task B, task B’s state, which includes the contents of the registers, program counter, and stack pointers, is saved, and that of task A is simply loaded from the task control block by the kernel

Task Preemption
• Ideally the kernel should have the ability to preempt low priority tasks with a higher priority task whenever one becomes ready (for a real-time system this is pretty much a requirement), such support is termed preemption support
• A preemptive kernel can be essential if it is necessary to absolutely guarantee the real-time response of particular tasks

Embedded System Design Considerations
There is little difference between the fundamental requirements of a general purpose OS and an embedded RTOS, however, there are a number of design considerations that apply specifically to embedded systems:
• Small footprint – there is a constant demand for ever smaller devices, and devices with more intelligence, a small embedded OS must often use no more than a couple of kilobytes of RAM and ROM memory
• Life time – embedded systems may be required to run for years without manual intervention, which means that the hardware and the software should never fail
Embedded System Design Considerations
• Failsafe – many embedded systems control devices that can be dangerous if they don’t work exactly as designed, therefore, the status of these devices has to be checked regularly. The embedded computer system itself, however, is one of these critical devices, and should also be checked, hence, hardware watchdogs are often included in embedded systems
• These watchdogs are usually retriggerable monostable timers attached to the processor’s reset input, the OS checks within specified intervals whether everything is working as desired, for example by examining the contents of status registers, it then resets the watchdog
• If the OS doesn’t succeed in resetting the timer, that means that the system is not functioning properly and the timer goes off, forcing the processor to reset
• Fast recovery – If the system does fail despite its designed robustness (e.g. RAM corruption from cosmic rays), there is usually no one around to take corrective actions, hence, the system itself should reboot autonomously, in a “safe” state, and “instantly” if it is supposed to control other critical devices
• Low power – embedded systems are often required to run for a long time on batteries (e.g. mobile phones), or are part of a larger system with very limited power resources (e.g. satellites)
• Low cost – embedded systems are often produced in quantities of several thousands or even millions, decreasing the unit price by even a small amount can generate enormous savings

RTOS timing Constraints
• Different applications have different timing constraints and in an ideal world any RTOS would be able to satisfy all of them
• In practice, however, this is not possible and in general the RTOS scheduling algorithms must be tailored to suit one of the following classes of time constraint:
• Deadline: a task has to be completed before a given instant in time, but when exactly the task is performed during the time interval between now and the deadline is not important (e.g. the buffer of a sound card must be refilled before it empties;the voltage on an output port must reach a given level before another peripheral device comes and reads that value)
• Zero execution time: the task must be performed in a time period that is absolutely minimized (zero in the ideal case), e.g. digital control theory assumes that taking a measurement, calculating the control action, and sending it out to a peripheral device all take place instantaneously
• Quality of Service (QoS): the task must get a fixed amount of “service” per time unit (“service” most often means “CPU time”, but could also be “memory pages”, “network bandwidth” or “disk access bandwidth”), this is important for applications such as multimedia (streaming audio or video) or network servers (e.g. in order to guarantee a minimum service level for voice over IP or other latency critical applications)
• The major problem with achieving any of these goals is that the scheduler needs complete knowledge about how long each task is going to take in the near future,and when it will become ready to run
• This information is almost impossible to get in practice, and even when it is available, calculation of the optimal scheduling plan is a search problem with high complexity, and hence high cost in time
• Different tasks compete for the same resources: processors, network, memory, etc., . . . much more than in the case of a general purpose OS
• Programmers of real-time systems have to take into account worst-case scenarios: if various tasks could be needing a service, then sooner or later they will want it at the same time
• The latency (or tardiness) of a task is the difference between the instant of time on which the task should have started (or finished) and the instant of time on which it actually did
• Latencies are due to several factors:
• the timing properties of processor, bus, memory (on-chip cache, off-chip RAM and ROM) and peripheral devices
the scheduling properties of the operating system
the preemptiveness of its kernel
the load on the system (i.e., the number of tasks that want to be scheduled concurrently), and
the context switch time (the time the processor needs to save the data of the currently running task, e.g. registers, stack, and IP, and replace it with the local data of the next scheduled task)

Wednesday, December 24, 2008

Touch Screen Technology and Applications

Touch Screen Technology and Applications

Today’s innovative technologies are countless. After the introduction of Touch screens in the technology era, it has replaced the conventional methods of screen displays and controls. Touch screens, or touch screen panels are display overlays which have the ability to display and receive information on the same screen. The effect of such overlays allows a display to be used as an input device, removing the keyboard and/or the mouse as the primary input device for interacting with the display's content. In simply, the screen’s control is by touching the menus or buttons on the screen to input or display the required output. This technology has also been used in applications of Graphical user interface (GUI) and entering data. Multi Touch screens also one among the touch screen technology for inputting two or more inputs at simultaneously.
The different types of touch screen technologies are Capacitive Touch screen Technology, Resistive Touch screen Technology, Infrared (IR) Touch screen Technology and so on.

The current applications of touch screen technology are ATM, Smart phones, PDA devices, Portable game consoles, Projector screens and so on. These screens are also popular in Museum displays, Room automation where as the keyboards and mice do not allow a satisfactory, intuitive, rapid, or accurate interaction by the user with the display's content.

Monday, December 22, 2008

Engineering Project Links for Final Semester Students

Engineering Project Links for Final Semester Students

I would like to share some of the Engineering projects related website links which will be very useful for referring their final engineering projects. I can find very few websites from blogs. Very few authors contribute for guiding the engineering students online. Some of these sites are really giving useful information related to our projects. I really thank all the owners of these sites.

1. http://www.makeitsolar.com/science-fair-ideas/index.htm
2. http://www.hobbyprojects.com
3. http://iprojectideas.blogspot.com/
4. http://www.solarlantern.blogspot.com/
5. http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/

6. http://forum.allaboutcircuits.com/showthread.php?t=3907
7. http://www.crazyengineers.com/forum/project-ideas-seminar-topics/3899-ce-ultimate-mini-project-ideas-seminar-topics-telecommunication-engineering.html

Based on the above links i have written some of the posts. These fruitful sites will definitely guide for the end semester projects.

Thursday, December 18, 2008

PSIM software

PSIM software
I have already discussed about various simulation software in previous blogs. In this connection, i would like to bring more about PSIM software which will be very useful for doing projects at UG and PG level. On request of some of our net friends, i would like give a details of PSIM software with an example.

PSIM is a simulation package specifically designed for power electronics and motor control. With fast simulation and friendly user interface, PSIM provides a powerful simulation environment for power electronics, analog and digital control, and motor drive system studies. PSIM is having three add-on Modules: Motor Drive Module, Digital Control Module, and SimCoupler Module. The Motor Drive Module has built-in machine models and mechanical load models for drive system studies. The Digital Control Module provides discrete elements such as zero-order hold, z-domain transfer function blocks, quantization blocks, digital filters, for digital control analysis. The SimCoupler Module provides interface between PSIM and Matlab/Simulink2 for cosimulation. The PSIM simulation package consists of three programs: circuit schematic program PSIM, PSIM simulator, and waveform processing program SIMVIEW1.

Typical uses of the software include.
• Math and computation
• Algorithm development
• Data acquisition
• Modeling, Simulation and prototyping.
• Data Analysis, Exploration and Visualization
• Scientific and Engineering graphics
• Application development, including graphical user interface building.

A circuit is represented in PSIM in four blocks: power circuit, control circuit, sensors, and switch controllers.
The power circuit consists of switching devices, RLC branches, transformers, and coupled inductors. The control circuit is represented in block diagram. Components in s domain and z domain, logic components (such as logic gates and flip flops), and nonlinear components (such as multipliers and dividers) are used in the control circuit. Sensors measure power circuit voltages and currents and pass the values to the control circuit. Gating signals are then generated from the control circuit and sent back to the power circuit through switch controllers to control switches.

Example:
To simulate the sample one-quadrant chopper circuit “chop.sch”:

• Start PSIM. Choose Open from the File menu to load the file “chop.sch”.
• From the Simulate menu, choose Run PSIM to start the simulation. The
simulation results will be saved to File “chop.txt”. Any warning messages
occurred in the simulation will be saved to File “message.doc”.
• If the option Auto-run SIMVIEW is not selected in the Options menu, from the Simulate menu, choose Run SIMVIEW to start SIMVIEW. If the option Auto-run SIMVIEW is selected, SIMVIEW will be launched automatically. In SIMVIEW, select curves for display.

Monday, December 15, 2008

Latest Trends in Nano Technology and applications

Nano Technology and applications
Nano technology has been revolutionized the world in all the field. The main features Nano Technology is creating miniature devices at Nano scale. Nano technology offers ways to create smaller, cheaper, lighter and faster devices that can do more and cleverer things, use less raw materials and consume less energy.Nano Robot
I have found recently an website which is specific to Nano technology, it talks on latest news, events, education, job career on this field, innovations and so on. Some of the applications of Nano technology are nano coatings which can repel dirt and reduce the need for harmful cleaning agents, or prevent the spread of hospital-borne infections, New-generation hip implants can be made more ‘body friendly’ because they have a nanoscale topography that encourages acceptance by the cells in their vicinity, nano technology based mobile phones which are small in size, faster with less prizes.
In addition to this, nanobots (Robots at nano level ) are used for drug injection at cell level. This novel techniques are used in Textile fields also. Its potential applications are plenty whichis going to replace some of the conventional technologies.
Nanowire

Saturday, December 6, 2008

World record by the first solar powered car’s round the world journey

World record by the first solar powered car’s round the world journey
I have been talking about the Green technology. A world record has been achieved by a Solar powered car by its world Journey. The Car named as Solartaxi has completed its journey about 32,000 mile and ended its journey at Poland (During the UN Climate talks).
The first solar powered car completing the world journey

This vechile is completely free from all sort of pollution. The features of solartaxi are

• Noiseless
• Speed upto 55 mphr.
• Travel 185 miles for full charge
• Economy: Open road with solar energy!
• Ecology: Zero CO2 emission!
• Always a reliable partner: High efficiency cells and an optimal support for every solar project.
• A new energy solution provides independence: 6m2 solar cells on a rooftop yield power for 15,000 km per year!
• Freedom: To drive up to 400 km with the latest ZEBRA battery technology.
• Max. speed: 90 km/h
• Light weight: 500 kg (+ 250 kg for thailer)
• Energy efficient: Consumption of 8 kWh/100 km (equivalent of 0.8 l petrol / 100 km)
Though the inital cost of this solar powered car is high, once mass produced, then it can be a boon for people on earth to have a green life.

Learn from Online teachers - A great opportunities for students from Brightstorm

Learn from Online teachers - A great opportunities for students from Brightstorm

The Internet era has taken the entire field and related technology revolutions are limitless. Yes, Students here after need not go to tuition classes in order to improve their grades, The door is now open for them to take the tuition classes online.
The Brightstorm has emerged in this online education field and offers online video courses related to the high school student subjects. The teachers who is online are expert in the specified subjects. These teachers highlight key information and provide clear explanations, making it easier to understand the subject, leading to improve student's grades.
Brightstorm

The Courses offered are interactive quizzes, practice problems and study guides to provide immediate homework help and will ensure your student is ready for their next test, essay. The registration is freely available, we can take free tests among the 19 courses offered. At the lowest prices they offer full materials and tests in our choice of courses.
So Now the parents and school students need not search for a good teacher to improve grades, Students can get all sort of info from online itself, specifically at home itself. You can get free registration on line here. https://www.brightstorm.com/register/register?a=10100

Friday, December 5, 2008

Green Revolution by Greatest Planet

Green Revolution by Greatest Planet
Global warming and the fight against it has been a top priority among the science world as well as in political concern on earth. Carbon emission due to the various action of human beings has been the cause for this global warming. In order to avoid or reduce the effect of global warming the Greatest Planet, a non profit, global environment organization has been working on many projects of carbon offset.
I have recently found such an organization online. Greatest planet assists the people (individuals and business people) all over the world to reduce the carbon emissions. Their aim is to see a healthy planet and a good life for everyone on it. Their vision has been focused as "a phrase intended to highlight both the privileges of living on this wonderful planet and the responsibilities of having a raised consciousness about climate change."
The Greatest planet website provide information on climate changes and it effect, various projects to reduce the effect of global warming like usage of Solar energy (Solar energy by using solar panels, Bio energy, Wind energy, Tree plantation and so on. They have listed top 10 projects by the Greatest Planet.
We can also get more info by their blog available in the resource centre. They also give tips on how to reduce the Co2 emission at our household. For example, The average household produces over 100 pounds of carbon dioxide per day.
At this time, we should also take right steps to reduce carbon emissions at our level. For example, we can use solar panels for lighting or for our household appliances, usage of hybrid vehicles instead of using conventional vehicles, tree plantation around our house, bringing awareness among the young world and so on. It is also our Prestige to do all these for saving our mother earth.

Wednesday, December 3, 2008

Simulation softwares for Power Electronics and Power Systems

Simulation software for Power Electronics and Power Systems
The mostly used software for simulation of Power electronics circuits or Power electronics controllers design are Matlab and Power SIM (PSIM).
Matlab software: Matlab software has number of toolboxes and Blockset which cater the need of all sort of simulations. The simulation environment are user friendly which are all built on the concept of Graphical User Interfaces. This mainly interact with the user and can be used for created and designing all kind of circuits and controllers. The basic models are available in the simulink.
Simulink provide the various form of input electrical sources, output scopes & displays, built in maths tools and user defined functions and so on. Some of the commonly used toolboxes Control system toolboxes, data and image acquisition toolboxes, SimPowersystems (Mainly for power systems and power electronics topics), Neural Network, Fuzzy logic toolboxes, simulink extras, DSP, Virtual reality toolboxes and so on. Matlab application
These toolboxes provides ther required tools or electrical and electronic components to design the desired power system and power electronics related engineering projects at UG and PG level.

PSIM software: Another main software used is PSIM. This is a simulation software developed mainly for power electronics and motor control applications. PSIM provides very efficient and powerful simulation environment for the said applications.
PSIM add-on modules are motor driver control, digital control module, thermal module, Simcoupler and Mag coupler modules. Among these modules, the simcoupler modules can be used to make interface between the PSIM software and Matlab software. Some features which are available in matlab can be interchangebly used in the PSIM simulation environment.
I would like to the features of the simulation softwares
1. These softwares provides user friends graphical interface, simple to use with fast simulation
2. Very interactive simulation environment
3. It saves time and cost in overall completing a project from design to testing stage

In addition to all the above the Power world, Mi Power are all the other simulation software exclusively available for Power system simulation environment. Some of the tools are available at free from these software vendors for Educational use.

Hobbyprojects - Review

Hobbyprojects - Review

While researching on net for engineering projects, there are thousands of websites. Some websites or blog site provide a worth of information related to Electrical, electronics, communications and other engineering fields. In this series while searching on net, i got this amazing site called as hobbyprojects.com which have collections of basic electronics circuits, electronics kits with novel ideas to advanced engineering projects with circuit descriptions and relevant working models.
This site mainly focuses projects on electronic, microprocessors, microcontrollers, PC based controllers useful for engineering students, electronic hobbiest and Research & Developers.They are adding new circuits or projects with links everyday. This site is really an electronic resource centre where we can access all the resources relected to electronics and engineering projects. In addition to this the resource centre provides tutorials on various categories. For example if you want to know about the 8085 microcontrollers, just go through the tutorials available on this site.
In the advanced section, hobbyprojects includes projects on Robotics, Power electronis controllers and so on. This will be a master guide for electronic enthusiast.


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