In this 20th century we have also come up with a smart way for cooking.

Have you ever wondered how does the electronic gadgets we use in our daily life works?

Almost all the electronic gadgets we come across in our daily lives are various types of embedded systems. Be it a digital camera or a mobile phone or a washing machine, all of them has some kind of processor functioning inside it. Combination of several processors is the embedded software. If hardware forms the body of an embedded system, embedded processor acts as the brain, and embedded software forms its soul. It is the embedded software which primarily governs the functioning of embedded systems.


C was developed by Kernighan and Ritchie to fit into the space of 8K and to write (portable) operating systems. Originally it was implemented on UNIX operating systems. As it was intended for operating systems development, it can manipulate memory addresses. Also, it allowed programmers to write very compact codes. This has given it the reputation as the language of choice for hackers too.

Embedded systems programming is different from developing applications on a desktop computers. Key characteristics of an embedded system, when compared to PCs, are as follows:

•  Embedded devices have resource constraints(limited ROM, limited RAM, limited stack space, less processing power)
• Components used in embedded system and PCs are different; embedded systems typically uses smaller, less power consuming components. Embedded systems are more tied to the hardware.

 Two salient features of Embedded Programming are code speed and code size. Code speed is governed by the processing power, timing constraints, whereas code size is governed by available program memory and use of programming language.  Goal of embedded system programming is to get maximum features in minimum space and minimum time.

Use of C in embedded systems is driven by following advantages

• It is small and reasonably simpler to learn, understand, program and debug.
•    C Compilers are available for almost all embedded devices in use today, and there is a large pool of experienced C programmers.
•  Unlike assembly, C has advantage of processor-independence and is not specific to any particular microprocessor/ microcontroller or any system. This makes it convenient for a user to develop programs that can run on most of the systems.
•    As C combines functionality of assembly language and features of high level languages, C is treated as a ‘middle-level computer language’ or ‘high level assembly language’
•   It is fairly efficient
•   It supports access to I/O and provides ease of management of large embedded projects.

What is the Difference between C & Embedded C?

1. Though C and embedded C appear different and are used in different contexts, they have more similarities than the differences. Most of the constructs are same; the difference lies in their applications.
2. C is used for desktop computers, while embedded C is for microcontroller based applications. Accordingly, C has the luxury to use resources of a desktop PC like memory, OS, etc. While programming on desktop systems, we need not bother about memory. However, embedded C has to use with the limited resources (RAM, ROM, I/Os) on an embedded processor. Thus, program code must fit into the available program memory. If code exceeds the limit, the system is likely to crash.
3. Compilers for C (ANSI C) typically generate OS dependant executables. Embedded C requires compilers to create files to be downloaded to the microcontrollers/microprocessors where it needs to run. Embedded compilers give access to all resources which is not provided in compilers for desktop computer applications.
4. Embedded systems often have the real-time constraints, which is usually not there with desktop computer applications.
5. Embedded systems often do not have a console, which is available in case of desktop applications.
6. So, what basically is different while programming with embedded C is the mindset; for embedded applications, we need to optimally use the resources, make the program code efficient, and satisfy real time constraints, if any. All this is done using the basic constructs, syntaxes, and function libraries of ‘C’.

Many advanced developments have taken place in the field of  microelectronics. Early 60’s saw the low density fabrication processes classified under Small Scale Integration (SSI) in which transistor count was limited to about 10. This rapidly gave way to Medium Scale Integration in the late 60’s when around 100 transistors could be placed on a single chip.Early seventies marked the growth of transistor count to about 1000 per chip called the Large Scale Integration. By mid eighties, the transistor count on a single chip had already exceeded 1000 and hence came the age of Very Large Scale Integration or VLSI.  Today many companies like Texas Instruments, Infineon, Alliance Semiconductors, Cadence, Synopsys, Celox Networks, Cisco, Micron Tech, National Semiconductors, ST Microelectronics, Qualcomm, Lucent, Mentor Graphics, Analog Devices, Intel, Philips, Motorola and many other firms have been established and are dedicated to the various fields in "VLSI" like Programmable Logic Devices, Hardware Descriptive Languages, Design tools, Embedded Systems etc.

VLSI Design:


VLSI chiefly comprises of Front End Design and Back End design these days. While front end design includes digital design using HDL, design verification through simulation and other verification techniques, the design from gates and design for testability, backend design comprises of CMOS library design and its characterization. It also covers the physical design and fault simulation.

While Simple logic gates might be considered as SSI devices and multiplexers and parity encoders as MSI, the world of VLSI is much more diverse. Generally, the entire design procedure follows a step by step approach in which each design step is followed by simulation before actually being put onto the hardware or moving on to the next step. The major design steps are different levels of abstractions of the device as a whole:

1.      Problem Specification:  It is more of a high level representation of the system. The major parameters considered at this level are performance, functionality, physical dimensions, fabrication technology and design techniques. It has to be a tradeoff between market requirements, the available technology and the economical viability of the design. The end specifications include the size, speed, power and functionality of the VLSI system.

2.      Architecture Definition: Basic specifications like Floating point units, which system to use, like RISC (Reduced Instruction Set Computer) or CISC (Complex Instruction Set Computer), number of ALU’s cache size etc.

3.      Functional Design: Defines the major functional units of the system and hence facilitates the identification of interconnect requirements between units, the physical and electrical specifications of each unit. A sort of block diagram is decided upon with the number of inputs, outputs and timing decided upon without any details of the internal structure.

4.      Logic Design: The actual logic is developed at this level. Boolean expressions, control flow, word width, register allocation etc. are developed and the outcome is called a Register Transfer Level (RTL) description. This part is implemented either with Hardware Descriptive Languages like VHDL and/or Verilog. Gate minimization techniques are employed to find the simplest, or rather the smallest most effective implementation of the logic.

5.      Circuit Design: While the logic design gives the simplified implementation of the logic,the realization of the circuit in the form of a netlist is done in this step. Gates, transistors and interconnects are put in place to make a netlist. This again is a software step and the outcome is checked via simulation.

6.      Physical Design: The conversion of the netlist into its geometrical representation is done in this step and the result is called a layout. This step follows some predefined fixed rules like the lambda rules which provide the exact details of the size, ratio and spacing between components. This step is further divided into sub-steps which are:

    6.1 Circuit Partitioning: Because of the huge number of transistors involved, it is not possible to handle the entire circuit all at once due to limitations on computational capabilities and memory requirements. Hence the whole circuit is broken down into blocks which are interconnected.
      6.2 Floor Planning and Placement: Choosing the best layout for each block from partitioning step and the overall chip, considering the interconnect area between the blocks, the exact positioning on the chip in order to minimize the area arrangement while meeting the performance constraints through iterative approach are the major design steps taken care of in this step.
     6.3 Routing: The quality of placement becomes evident only after this step is completed. Routing involves the completion of the interconnections between modules. This is completed in two steps. First connections are completed between blocks without taking into consideration the exact geometric details of each wire and pin. Then, a detailed routing step completes point to point connections between pins on the blocks.
    6.4 Layout Compaction: The smaller the chip size can get, the better it is. The compression of the layout from all directions to minimize the chip area thereby reducing wire lengths, signal delays and overall cost takes place in this design step.
    6.5 Extraction and Verification: The circuit is extracted from the layout for comparison with the original netlist, performance verification, and reliability verification and to check the correctness of the layout is done before the final step of packaging.

7.      Packaging: The chips are put together on a Printed Circuit Board or a Multi Chip Module to obtain the final finished product.

Initially, design can be done with three different methodologies which provide different levels of freedom of customization to the programmers. The design methods, in increasing order of customization support, which also means increased amount of overhead on the part of the programmer, are FPGA and PLDs, Standard Cell (Semi Custom) and Full Custom Design.

While FPGAs have inbuilt libraries and a board already built with interconnections and blocks already in place; Semi Custom design can allow the placement of blocks in user defined custom fashion with some independence, while most libraries are still available for program development. Full Custom Design adopts a start from scratch approach where the programmer is required to write the whole set of libraries and also has full control over the block development, placement and routing. This also is the same sequence from entry level designing to professional designing.

Being an electronic students, we know many components and  their usage. Having real time exposure will help you to gain in depth knowledge about the component and how it works in the real scenario.. One can easily build  small circuits  using many electronic components in their leisure time .Here is an example on how to design a simple audio amplifier.

Required components:

• LM 386 semiconductor (IC) 
• 100 micro Farad capacitor 
•  220 micro Farad capacitor 
•  10 ohm resistor 
•  5 kilo ohm variable resistor 
• 100 ohm variable resistor 
• 0.01 capacitor 
•  0.047 capacitor 
•  Wires 
•  9V Battery clip 
•  9V Battery 
•  3.5mm stereo jack male 
•  3.5mm stereo jack female 
•  Project board (or you can use dotted board and solder) 

1. Now draw a circuit diagram which indicates where to place the components on the bread board.

   Fig:Circuit Diagram

2. First place the LM 386 IC and take a wire and join the 3rd pin to 4th pin(GND pin).
3. Join the one pin of 0.01 capacitor with the 2nd pin of IC. The other pin of the capacitor should be joined with the input.
4. Now join the 1st pin of IC with the A pin of the 5 k ohm variable resistor. 
5. Join th A pin of this variable resistor with the C pin.Lastly join the 8th pin of IC with the B of this variable resistor.This becomes the Gain.
6. Join the +ve side of the 100 micro Farad capacitor with 6th pin of the IC.The -ve of this capacitor should be joined with GND pin (4th pin of IC).
7. Join the 5th pin of IC with one side of 10 ohm resistor, the other side of the resistor should be joined with the one pin of 0.047 capacitor. The second pin of the capacitor should be joined with the GND pin (4th pin of IC). 
8. Join the +ve pin of the 3.5mm stereo jack female with the C of the 100 ohm variable resistor.And the GND of the female jack should be attached with the GND of the IC (4th pin of IC). 
9. Now again join the 5th pin of the IC with the +ve side of 220 micro farad, the -ve side of the pin should be attached with the A of the 100 ohm variable resistor.The B pin of the variable resistor should be connected to the GND pin (4th pin of IC).This becomes the Volume controller.
10. Join the +ve pin of the 3.5mm stereo jack female with the C of the 100 ohm variable resistor.And the GND of the female jack should be attached with the GND of the IC (4th pin of IC). 
11. Join the +ve of the 3.5 mm stereo jack male with the other side of the 0.01 capacitor and join the GND of the male jack with the GND of the IC.
12. Last but not the least join the +Ve of 9V battery with the 6th pin of IC and -Ve of the battery with the 4th pin of IC. 

Join the male jack with your mp3 player or musical instrument and female with the speakers.Now adjust the Volume and Gain to get the best and loudest possible sound.I should notify you that with this amplifier only one speaker will work.And do the adjustment from low to high.Do the adjustment carefully or it can damage your speakers.

You can change the input jacks as your requirement.You can add a 220 micro farad variable capacitor instead of simple 220 micro farad capacitor to change the bass.

Your audio amplifier is ready :)

Keywords: audio amplifier circuit, electronic tutorials, audio circuit.....

Wireless technology has propagated the use of sensor networks in many applications. Sensor networks join small sized sensors and actuators with general purpose computing components. Such networks comprise of hundreds and sometimes thousands of self-functioning, low power, inexpensive wireless nodes to observe and influence the surroundings.

Wireless sensor networks usually consist of a single or multiple base stations acting as points of centralized control, whereby they provide access to other networks. These networks are unique in their dynamic network topologies. A network topology is usually selected depending on the type of application the sensors are used for or where it is situated. The types of topologies used for sensor networks include star, mesh, star-mesh etc.




 In Wireless sensor networks there are two kinds of wireless nodes; sensor and base station nodes. The main function of the base station (also referred to as sinks) relies on managing the actions executed to provide reliable and efficient sensing support. It provides a gateway to other networks or acts as a data storage processing data in a powerful way. It even acts as an access point to human interface for human interaction, and is capable of broadcasting control data in the network or removes data from it. The base station node will calculate and send the even source, its position and a timestamp to the analysis centre. If an alert is received by the base station regarding a target, an identity of the target will be allocated allowing all related alerts getting appropriate management.

Every sensor within the network primarily consists of a certain amount of power and a base station that provides entrance to other networks or to the centre analysis. It is important to know that base stations have significant features over other nodes in the network. They comprise of adequate battery power to exceed the existence time of all sensor nodes, and have the capacity to save cryptographic keys, well-built processors and resources to commune with external networks. In contrast to the base stations, in a sensor network a large number of sensor nodes are connected together with radio frequency communication links, giving much significance to broadcasting in the network. Protocol procedure plays a vital role. Although they have concerns with trust assumptions, energy usage is decreased when using these protocols. The main purpose of these nodes is to gather information or events occurring from their targets.

The main functions associated with sensor nodes include: collecting information on the target with consideration to their nature and positioning, which involves the communication from nodes to base stations regarding for example sensor readings and particular alerts. Nodes should be capable of producing real-time events on detected targets using the base station node to forward an even transmission to a centre for the event to be analyzed. Base stations may request updates from sensor nodes, resulting in base station to node communication. Finally the generated events will be relayed to the base station from the sensor nodes. In this part of the communication architecture, base stations contact all of the nodes it is assigned for purposes such as routing beacons or reprogramming of the complete network. 

We all very well know that satellites are used for communication...but do you know how they work???

Satellites are used for a number of purposes.Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites.

A satellite works by receiving radio signals sent from the Earth and resending the radio signals back down to the Earth. In a simple system, a signal is reflected, or"bounced," off the satellite. For example, it is possible to bounce a signal off the surface of the Moon back down to Earth. Because the Moon is very far away, for this to work the signal from the Earth must be very strong and the receiver receiving the signal must be sensitive enough to detect the very weak signal receive back from the moon.

Unlike a passive satellite such as the moon or the early ECHO satellite, a modern communications satellite receives the radio signal and sends it back down to Earth stronger than it was received. This process is called "amplification"of the radio signal. In addition to amplifying the signal, a communications satellite also typically converts the radio from one frequency to another so that the signal getting sent down is not confused with the signal being sent up.People communicate to a satellite using an antenna on the ground, which called an "earth station" in technical terms.The earth station sends up radio signals to the satellite.These signals are called "uplinks."The satellite receives these signals, makes them stronger,and then re-transmits them back down to the Earth. These signals back to the Earth are called "downlinks."



Sometimes the uplink and downlink earth stations perform various specialized functions. For example, some uplink stations deliver - or "feed" - video or audio programming to the satellite, which is then retransmitted to users all over the United States or world. These links are called "feederlinks." Other uplink stations are used to control the satellite. Such uplinks are called "control" links. Downlink stations can used to allow the satellite to connect with the telephone network or the Internet. These stations are often called "hub" stations or "gateway" stations. Other earth stations receive information from the satellite on how it is performing and what it is doing. This information is called "telemetry." Users also directly send information up to satellites and receive information directly from the satellite. The links that connectusers to the satellite are called "service links." The area that can be served by a satellite is determined by the "footprint" of the antennas on the satellite. The "footprint" of a satellite is the area of the Earth that is covered.

Bharat dynamics limited(BDL) is one of the India’s manufacturers of ammunitions and missile systems.


Posts Name : Engineers and Associates

No Of Vacancies : 30

Qualification : Candidates  must have degree of BE/ B.Tech in ECE / Electronics & Instrumentation Engineering / Electronics Engineering with Post Graduation (ME/ M.Tech/ MS) in Microwave & Radar Engineering / Wireless & Mobile Communication / Control System / Digital Signal Processing / Image Processing / VLSI Design / Embedded Systems Design / Electronic System Design/ Computer Science & Engineering (CSE) with Post Graduation (ME/ M.Tech/ MS) in CSE / Software Engineering / mechanical engineering/ CAD/ CAM /CAE/ Opto- Electrics / Photonics/ Aerospace / Aeronautical Engineering with Post Graduation (ME/ M.Tech/ MS) in Aerostructures / Aerospace / CFD, along with Doctoral Degree (Ph.D) in Computational Fluid Dynamics in Airborne System / Aerodynamic Applications from recognized university or institute.

Starting date to apply  Online : 13th June 2015

Last date to apply Online : 26th June 2015

In our daily life we come across numerous electronic circuits which are build up using  various electronic components.Here is is brief overview about the functions of some of the basic components.

Krishak Bharati Cooperative Limited (KRIBHCO) jobs for Graduate Engineer Trainee in Noida.

Qualification : BE/B.Tech(chemical engineering, Civil, CSE, ECE, Mechanical Engineering, Electrical)

Position : Graduate Engineer Trainee

Hiring Process : Written test

Location : Noida

How to apply : Online application will be accepted from 3 June 2015 (Wednesday ) to midnight of 24 June 2015 (Wednesday). Application should addressed to Krishak Bharati Cooperative Limited, Corporate HR Div, KRIBHCO Bhawan, A-10, Sector-1, Noida-201301 

Last Date : 24 Jun 2015 

Click here to Apply Online

Click here to view Notification

Indian Institute of Astrophysics (IIA) is recruiting  Electronics  engineers as  Engineer Trainee at Bangalore.

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