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FM transmitter for TV audio and video

2011-09-19T08:04:00.000-07:00

FM transmitter for TV audio and video :-
Introduction of FM Transmitter:-

The FM TV transmitter uses standard 1 FM modulation for sound and PAL for video modulation.
Thus we can say that in this FM transmitter two type of modulations are being performed on two different signal, one for voice or audio signal modulation and the second for the video signal modulation. We will discuss these two modulation and how these are going to perform practiclly in the FM transmitter ciruict.
The Audio signal modulation will be discussed first which is modulated using a pre-amplifier circuit consisting of a transistor Q1 and some associated components.
While the transistor Q2 is performing two jobs:
1. production of carrier frequency and
2. modulation.
The pre-amplified audio signal from transistor Q1 is fed to the base of transistor Q2 for modulation.
The Capacitor C5 and inductor L1 forms the tank circuit which is responsible for producing the carrier frequency.

Now we will discuss the video signal modulation, the video signal is fed to the emitter of transistor Q2 via POT (variable resistor)R7 for modulation. Afte the audio and video modulation performed at transistor Q2 is ready to transmit. The modulated composite signal (audio+video) is transmitted by the antenna A1.

Construction of inductor used in the FM transmitter:-
Here we will discuss the construction of the inductor L1 used in the above transmitor circuit.
The Inductor L1 can be made by making 4 turns of 24SWG enameled copper wire on a 6mm dia: plastic former.

The Tansformer used in Transmittor:-

The tranformer T1 can be a radio frequency transformer with built in capacitor. This transformer can be obtained from any old readio.
Antenna A1 can be a 1M long copper wire. (Experiment with the length to get optimum performance). This transmitter is working in VHF band somewhat between 50 – 210MHz. This transmitter is compatible only with PAL B and PAL G systems.

List of Component used in the transmittor:
R1 = 10KOhm
R2 = 47KOhm
R3 = 15KOhm
R4 = 8.2KOhm
R5 = 47KOhm
R6 = 47KOhm
R7 = 1Kohm
R8 = 75Ohm
C1 = 10uF/25Volt
C2 = 0.001uf/10nF
C3 = 100nF
C4 = 10nf
C5 = 47pF (variable capacitor)
C6 = 10nF
C7 = 10pF
C8 = 27pF
c9 = 100nF
C10 = 470uF
c11 = 10nF
C12 = 220uF/25Volt
Q1 and Q2 = BC547 NPN transistor
T1 = T1 can be a radio frequency transformer with built in capacitor. (Can be found on old transistor radio boards).
L1 = 4 turns of 24SWG enameled copper wire on a 6mm dia: plastic former.
S: elektroarera.blogspot.com

Generate pulses by Pulse Modulation Width PWM technique

2011-09-19T07:43:00.000-07:00

Generate pulses by Pulse Modulation Width PWM technique :-

Introduction of PWM TECHNIQUE:-
Pulse Modulation Witdh is a technique in which the width of pulse is critically controlled and used which refelects the duty cycle. The PWM is oftenly used to control the power of a load. for example the typical use of PWM is the DC motor speed control, or the power of heater or speed of fan. The PWM is generated at low voltage and then feeded to transistors or IGBTs to drive the high current load.Pulse width modulation (PWM) is a technique in which a series of digital pulses is used to control an analog circuit. The length and frequency of these pulses determines the total power delivered to the circuit. PWM signals are most commonly used to control DC motors, but have many other applications ranging from controlling valves or pumps to adjusting the brightness of an LED.

Generation of PWM Technique:-

First of all we will discuss the generation of PWM.Using digital pulses to create some analog value other than just ‘high’ and ‘low’ signal levels. Many digital systems are powered by a 5-Volt power supply. Here we will learn how to generate the pulse width modultion of a fixed frequency pulses. The method used to generate the train of pulses which are generated through PWM circuit here is made up of a simple PWM circuit made of Op-Amp, which consists of Schmitt Trigger circuit, integrator and comparator. Here OPAMPs will be used to generate the PWM signal and then generated pulses will be feeded to IGBT to control the power of speed.The duty cycle is defined as the percentage of digital ‘high’ to digital ‘low’ signals present during a PWM period.

PWM signals from Op-Amps circuit:-

The Op-Amps are used to have Schmitt Trigger function which will produces a square wave. This square wave will be converted by the integrator sawtooth wave (which is also called Ramp), and this Ramp is compared with a reference voltage. To adjust therequired voltage level that can be changed much voltage. So the result of the RAMP is a PWM signal output, ready to use any where.The PWM resolution is defined as the maximum number of pulses that you can pack into a PWM period.

Here are two different versions of the circuits. These two schematics are variations on another PWM circuit. The circuit diagrams are for 12V operation only. There are high side in which positive PWM signal is generated (common ground) and low side in which negative PWM signal is generated(common +12V) versions. The low side version of the circuit uses an N Channel FET, the high side version of the circuit uses a P Channel FET. N Channel devices tend to handle more current than P Channel devices, they are also less expensive. The high side version of the circuit is useful when one side of the load has to be grounded.
Uses for PWM:
1) To digitally create an analog output voltage level for control functions and power supplies.
2) To digitally create analog signals for arbitrary waveforms, sounds, music and speech.
This circuit can switch a fairly high amount of current, an IRFZ34N MOSFET can handle over 35 Amps if connected to a proper heat sink. Higher power FETs, such as the IRFZ48N or IRF1010Z can be substituted if even larger currents are required. It is also possible to connect multiple FETs in parallel for even more current capacity. Always use thermally conductive grease between the FET and the heat sink, and remember that the heat sink is electrically live.Pulse-Width Modulation (PWM) allows for electronic control over DC motor speed or LED brightness.

Pulse-Width-Modulation (Pwm) Control Circuit

Pulse width modulation (PWM) is a technique in which a series of digital pulses is used to control an analog circuit. If you wish to use the Inductive loads (like motors), then you may require special care since they can generate large voltage spikes that can damage the MOSFET. Replacing the 1N4002 with a fast recovery diode may help absorb the reverse voltage kick when driving an inductive load such as a motor. If you use these circuits for experiments with electric vehicles, be sure to install a circuit breaker in series with the battery, the circuit breaker should be easy to reach by the driver. This is especially important due to the fact that when MOSFETs fail, they often short out, leaving the motor on at full speed.

Temperature Data Recorder microcontroller based

2011-09-19T00:48:00.000-07:00

The keypad has 6 buttons connected by a matrix - "Arrow", "OK" (left-bottom), and "The Return" (right-bottom). When held up OK at boot time recorder (reset) mode turns on the configuration where you can set the current time (in the future there will be more options.) The display is a 16-character on the controller module with HD44780 bought for as little as 5.5 zł Lispole store . Is displayed on the current time and temperature alternately with the date. Unlike the first version, on the board there are three indicator lights (Power, Status - flashes every 5 seconds, the record \ reading from SD (SPI) \ RTC (I2C) \ Thermometer (1Wire)) and a beeper that sounds when you press it buttons at the configuration and control signals at the start. Additionally, the board's pin RS232 (TTL), useful for debugging.

In this data logger project the memory issues has been significantly reduced, memory card slot went to the back. The power transistors control peripherals (clock / thermometer / card / lcd) and backlit display and a second crystal oscillator for the clock wybudzającego 32k from sleep mode. As before, all the elements are in a housing for mounting hole (except the slot for SD / MMC card. The system can be easily expanded by adding additional slot eg humidity sensor, pressure, anemometer, etc.

C program is also a lot has changed. In contrast to the carelessly written and unfinished firmware version 0.2x (includy. Cw main, etc..), Is nicely divided into modules, optimized and stable. No longer hangs when removing and inserting cards, etc. In addition, Dharmaniego resigned from the library, where I found a lot of errors for the better - Fatfs . Now, in addition to the recorder supports FAT32, FAT12 and FAT16 systems. Also was good support for energy conservation. In economy mode the display is off, peripherals turned on only when needed, and after writing the microcontroller goes to sleep until the next measurement, which significantly reduced power consumption. According to my cheap, Chinese multimeter recorder takes about 13-14uA in sleep.

SOURCE =:- http://silent.it.cx/home/2010/05/13/rejestrator-temperatury-v2/

Kitchen Fan controller with LM35 and LM3914

2011-09-18T02:23:00.000-07:00

This is a very simple temperature controller circuit diagram which can be used any where to control the temperature with fan. The temperature sensor LM35 is used to sense the temperature and the controlling device is LM3914.

Above is the Circuit Schematic for Kitchen Fan Controller:-

In this project a Exhaust fan is being controlled which is an important component in kitchens. The project is a simple temperaature controller to control kitchen fans by monitoring the ambient temperature of kitchen regularly and give the commands to fan accordingly. The sensor or transducer used in this temperature controller is precision integrated temperature sensor chip LM35 (IC1). The decision to turn ON or OFF is done with the help of LM3914 the popular LED driver LM3914 (IC2).
The prset temperature input to the temperature controller is feeded through the switches.User can switch three presetted temperature levels using a jumper/slide switch (JP1), which determines the heat level to activate the relay and hence the electric exhaust fan wired through the relay contacts. It works off 12V DC power supply.
Only one adjustment is required in this kitchen exhaust fan controller circuit. After construction, set jumper point in its first position, ie base terminal of T1 is connected to pin 13 of IC2 and adjust the preset P1 carefully so that relay RL1 is energised when ambient temperature level reaches near 29^oC. However this is not very critical as you can select any threshold level by connecting the jumper points to other unused output pins of IC2 (here only 3 outputs are used).
S: electroschematics.com/6319/kitchen-exhaust-fan-controller/

contruction of personal Radar System using PIC MIcrocontroller PIC18f452

2011-09-18T02:05:00.000-07:00

Personal Radar System using PIC MIcrocontroller PIC18f452 is a microcontroller hobby project. The circuit diagram of radar is attached here below seemed a little bit simple schematic but you need careful reading of PIC18f452 radar circuit to avoid any damage. The project of personal Radar System using PIC MIcrocontroller PIC18f452 uses three main devices to create the personal radar system which are listed as below:
1. The IR Range sensor gives output,
2. The pic microcontroller PIC18f452 processes the necessary instruction to carry out the operation smoothly.
3. The displays the output on the led array. This is the output of the radar system.

Functionality of IR Radar SYSTEM :-

The main function of the project is to create and have a simple functionality of a working IR radar system. The system will only be required to measure close proximity at an angle of 90 degrees as seen in the example above. The range of system is roughly 4-30cm, 20-150cm & 1m-5.5m depending upon which sensor you choose to use.

Electrical Parts
LM7805 5v Voltage Regulator
PIC 18F452 Microcontroller
GP2D120 IR Sensor
4 or 8 MHz Oscillator
SPST Switch
1µF Capacitor
30 pin SIPs
5x 74LS373 Latches
Prototype Board
Solder
36x LEDs
Wire 30 AWG (aka Wirewrap)
Wirewrap Tool
Soldering Iron

Personal Radar

source of this information is http://www.pyroelectro.com/

Selection Guide of Microcontrollers for automation projects

2011-09-13T01:06:00.001-07:00

In 1981, Intel Corporation introduced an 8-bit microcontroller called the 8051. This microcontroller had 128 bytes of RAM, 4K bytes of on-chip ROM, two timers, one serial port, and four ports (each 8-bits wide) all on a single chip. At the time it was also referred to as a “system on a chip”. The 8051 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by the CPU. The 8051 has a total of four 1/O ports, each 8 bits wide. Although the 8051 can have a maximum of 64K bytes of on-chip ROM, many manufacturers have put only 4K bytes on the chip.

The 8051 became widely popular after Intel allowed other manufacturers to make and market any flavor of the 8051 they please with the condition that they remain code-compatible with the 8051. This has led to many versions of the 8051 with different speeds and amounts of on-chip ROM marketed by more than half a dozen manufactures. It is important to note that although there are different flavors of the 8051 in terms of speed and mount of on – chip ROM, they are all compatible with the original 8051 as far as the instructions are concerned.

The following link was also given in the last post;

http://www.atmel.com/dyn/products/devices.asp?family_id=604

Now here you can see a lot number of MCU. I will describe them one by one so that the chioce can be made easy.

1-CAN Networking MCUs; CAN stands for "Control Area Network". These MCU have built-in error-detection and error-correction capabilities. Using serial Communication MCU is connected to the Network. These MCU are used for industrial purposes for automotive engine control communication in cars and buses. Similarly it is used in Automotive industry for different manufacturing processes, in avionics, in elevators and automatic doors.
So, its enough powerful. But certainly its a not good thing to start for beginners.

2-Flash (Reprogrammable) MCUs; The flash microcontrollers can be re-programmed after they are shipped. Data written to flash memory can be electrically erased, allowing new data to be written. For older types of flash memory, which use two power supplies (in addition to the power supply for VDD, a separate power supply is provided for VPP for programming), the program can be overwritten by using a dedicated flash programme. More recent types of flash memory are single power supply versions (which do not need a separate power supply for programming). Besides dedicated flash programmers, there are also other ways to program/reprogram and write new data to these devices. Also, among the microcontrollers with single power supply type flash memory that can be programmed after shipment, there are some in which part of the flash memory used to store data instead of an EEPROM. Thus, flash microcontrollers can serve a wide range of applications. more product families that use only flash memory and no longer include mask ROM.These MCU includes AT89CX family MCUs which we will use in our circuits. The detail of these and other MCU can be obtained from the address given below;

http://www.atmel.com/dyn/products/param_table.asp?family_id=604&OrderBy=part_no&Direction=ASC

If you go to the this link you can see the AT89CX family based MCUs including MCU from AT89C2051 to AT89S8253. You can use use AT89C51 MCU which is not given in the list or you can use AT89LS51/52 and AT89S51/52 from the list.

3-Flash ISP (In-System Programmable); These MCU are based on the 8051 architecture.
These MCU have the non-volatile memory (means that memory will not be washed away when the power is Off), The On-chip ISP Flash allows the Program memory to be re-programmed In-System through an SPI serial interface The on-chip FLASH memory can be programmed by byte or by block, either in parallel or in serial mode. We can use these MCU where we need to program the memory during system is running and we want to program the MCUs without removing them from the system, but certainly we are not at this level and also these MCUs are expensive.

4-Flash ISP - Single Cycle Core; For a CPU to execute an instruction takes a certain number of clock cycle. in 8051 family these clock cycles are referred to as machine cycles. THis length of machine cycle depends upon the frequency of the oscillator which we will discuss in other posts. The 8051 CPU requires 12 clock cycles to execute a single instruction. But this family of MCU consists of high performance 8-bit microcontrollers that execute most instructions in
a single clock cycle, which certainly reduces the delay in executing the instructions. You can say these MCUs are 12 times more faster than traditional 8051 MCU. These MCU are used in battery management, universal remotre control and in industrial and motor control

5- Lightning MCU; These MCU are dedicated to Lightning control. These are not used in common applications.Application include street lightning, lightning for marriages, high intensity flourscent lamps, etc.

6-OTP (One-Time Programmable); As the name suggests, these MCU are only one time programmable, means once they are programmed they cannot be programmaed again. These MCU are used in industrial purposes and for manufacturing where the products are made and the MCU used need not to be programmed again and again. EPROM is similar to OTP memory which can be cleared or deleted using UV(Ultra Violet) rays which a user cannot, but the difference is in their packaging. But in our case we need to reprogram a MCU so these cannot be used.

7- With and Without ROM; You can understand from name that these MCU have either ROM or they are without ROM. Mask ROM versions are semi-custom products in which user programs are written to this ROM before the product is shipped.ROMless versions connect to external ROMs that are programmed for various applications. These MCUs are designed for systems that can switch among various external and replaceable ROMs, such as for testing, evaluation, etc.

8-USB MCUs; Instead of serial and parallel communication, today USB has got more popularity due to increase in data rate and ease of connecting more devices on a single port. Data transferred to the microcontroller of a device from a serial peripheral interface (SPI) can be sent directly to the PC through a USB connection.

Atmel Product Guide;

www.partsearch.ru/_files/ATMEL_GUIDE.pdf

Find the MCU according to your need;

http://www.keil.com/dd/search_parm.asp

Different questions regarding type of MCU;

http://www.necel.com/en/faq/mi_com/__com_kind.html
http://www.geocities.com/shahzadahmadmalik/guide.html

About Atmel; Founded in 1984, Atmel Corporation is headquartered in San Jose, California San Jose is the third-largest city in California, and the tenth-largest in the United States. It is the county seat of Santa Clara County. With manufacturing facilities in North America and Europe. Atmel designs, manufactures and markets worldwide, advanced logic, mixed-signal, nonvolatile memory, MCU and RF semiconductors. Atmel is also a leading provider of system-level integration semiconductor solutions using CMOS(Complementary Metal Oxide Semiconductor) Pronounced "c-moss." The most widely used integrated circuit design. It is found in almost every electronic product from handheld devices to mainframes. , BiCMOS, bipolar SiGe, and high-voltage BCDMOS process technologies.
Atmel product and financial information can be retrieved from its Fax-on-Demand service. In North America call 1-(800) 292-8635. Internationally from a fax phone, dial 1-(408) 441-0732. Requests may be sent via e-mail to literature@atmel.com or by visiting Atmel's website at www.atmel.com.
Atmel Wireless & Microcontrollers Division product information may be retrieved at www.atmel-wm.com.

Intel Atmel 8051 Microcontroller

2011-09-13T01:05:00.001-07:00

In 1981, Intel Corporation introduced an 8-bit microcontroller called the 8051. This microcontroller had 128 bytes of RAM, 4K bytes of on-chip ROM, two timers, one serial port, and four ports (each 8-bits wide) all on a single chip. At the time it was also referred to as a “system on a chip”. The 8051 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by the CPU. The 8051 has a total of four 1/O ports, each 8 bits wide. Although the 8051 can have a maximum of 64K bytes of on-chip ROM, many manufacturers have put only 4K bytes on the chip.

The 8051 became widely popular after Intel allowed other manufacturers to make and market any flavor of the 8051 they please with the condition that they remain code-compatible with the 8051. This has led to many versions of the 8051 with different speeds and amounts of on-chip ROM marketed by more than half a dozen manufactures. It is important to note that although there are different flavors of the 8051 in terms of speed and mount of on – chip ROM, they are all compatible with the original 8051 as far as the instructions are concerned.

The following link was also given in the last post;

http://www.atmel.com/dyn/products/devices.asp?family_id=604

Now here you can see a lot number of MCU. I will describe them one by one so that the chioce can be made easy.

1-CAN Networking MCUs; CAN stands for "Control Area Network". These MCU have built-in error-detection and error-correction capabilities. Using serial Communication MCU is connected to the Network. These MCU are used for industrial purposes for automotive engine control communication in cars and buses. Similarly it is used in Automotive industry for different manufacturing processes, in avionics, in elevators and automatic doors.
So, its enough powerful. But certainly its a not good thing to start for beginners.

2-Flash (Reprogrammable) MCUs; The flash microcontrollers can be re-programmed after they are shipped. Data written to flash memory can be electrically erased, allowing new data to be written. For older types of flash memory, which use two power supplies (in addition to the power supply for VDD, a separate power supply is provided for VPP for programming), the program can be overwritten by using a dedicated flash programme. More recent types of flash memory are single power supply versions (which do not need a separate power supply for programming). Besides dedicated flash programmers, there are also other ways to program/reprogram and write new data to these devices. Also, among the microcontrollers with single power supply type flash memory that can be programmed after shipment, there are some in which part of the flash memory used to store data instead of an EEPROM. Thus, flash microcontrollers can serve a wide range of applications. more product families that use only flash memory and no longer include mask ROM.These MCU includes AT89CX family MCUs which we will use in our circuits. The detail of these and other MCU can be obtained from the address given below;

http://www.atmel.com/dyn/products/param_table.asp?family_id=604&OrderBy=part_no&Direction=ASC

If you go to the this link you can see the AT89CX family based MCUs including MCU from AT89C2051 to AT89S8253. You can use use AT89C51 MCU which is not given in the list or you can use AT89LS51/52 and AT89S51/52 from the list.

3-Flash ISP (In-System Programmable); These MCU are based on the 8051 architecture.
These MCU have the non-volatile memory (means that memory will not be washed away when the power is Off), The On-chip ISP Flash allows the Program memory to be re-programmed In-System through an SPI serial interface The on-chip FLASH memory can be programmed by byte or by block, either in parallel or in serial mode. We can use these MCU where we need to program the memory during system is running and we want to program the MCUs without removing them from the system, but certainly we are not at this level and also these MCUs are expensive.

4-Flash ISP - Single Cycle Core; For a CPU to execute an instruction takes a certain number of clock cycle. in 8051 family these clock cycles are referred to as machine cycles. THis length of machine cycle depends upon the frequency of the oscillator which we will discuss in our later posts. The 8051 CPU requires 12 clock cycles to execute a single instruction. But this family of MCU consists of high performance 8-bit microcontrollers that execute most instructions in
a single clock cycle, which certainly reduces the delay in executing the instructions. You can say these MCUs are 12 times more faster than traditional 8051 MCU. These MCU are used in battery management, universal remotre control and in industrial and motor control

5- Lightning MCU; These MCU are dedicated to Lightning control. These are not used in common applications.Application include street lightning, lightning for marriages, high intensity flourscent lamps, etc.

6-OTP (One-Time Programmable); As the name suggests, these MCU are only one time programmable, means once they are programmed they cannot be programmaed again. These MCU are used in industrial purposes and for manufacturing where the products are made and the MCU used need not to be programmed again and again. EPROM is similar to OTP memory which can be cleared or deleted using UV(Ultra Violet) rays which a user cannot, but the difference is in their packaging. But in our case we need to reprogram a MCU so these cannot be used.

7- With and Without ROM; You can understand from name that these MCU have either ROM or they are without ROM. Mask ROM versions are semi-custom products in which user programs are written to this ROM before the product is shipped.ROMless versions connect to external ROMs that are programmed for various applications. These MCUs are designed for systems that can switch among various external and replaceable ROMs, such as for testing, evaluation, etc.

8-USB MCUs; Instead of serial and parallel communication, today USB has got more popularity due to increase in data rate and ease of connecting more devices on a single port. Data transferred to the microcontroller of a device from a serial peripheral interface (SPI) can be sent directly to the PC through a USB connection.

Atmel Product Guide;

www.partsearch.ru/_files/ATMEL_GUIDE.pdf

Find the MCU according to your need;

http://www.keil.com/dd/search_parm.asp

Different questions regarding type of MCU;

http://www.necel.com/en/faq/mi_com/__com_kind.html
http://www.geocities.com/shahzadahmadmalik/guide.html

About Atmel; Founded in 1984, Atmel Corporation is headquartered in San Jose, California San Jose is the third-lar 1-(800) 292-8635. Internationally from a fax phone, dial 1-(408) 441-0732. Requests may be sent via e-mail to literature@atmel.com or by visiting Atmel's website at www.atmel.com.
Atmel Wireless & Microcontrollers Division product information may be retrieved at www.atmel-wm.com.

Programming languages for the microcontroller 8051

2011-09-13T01:04:00.001-07:00

Most commonly used are BASIC, C, and Assembly. BASIC is now out dated and was used on early Microcontrollers, Assembly is low level language i.e. more close to machine language so its little hard for beginners to adopt this language but it the strongest of all. The one remaining is C language. It is high level language i.e. more close to human understanding so it is preferred to use, but remember every language has its pros and cons. It is preferred that you should learn only C , because it is enough for making applications regarding MCU(Micro Controller Unit). You may not need to learn Object Oriented Programming.
The good point to start learning C is a small book named; “LET US C” whose author is "Yashwant Kanetkar". This book is very simple in language and bvery very easy to learn C from this book. It has simple progams to learn and practice. This book is easily available in market and is very cheap also. You can read and download it from internet at this address;
(LET US C- Fifth Edition);
http://www.esnips.com/doc/3c2d1754-cd4c-4b90-ad23-0fcd22a49ccb/Let-Us-C---Yashwant-Kanetkar
http://kewlshare.com/dl/6bbc33d1d5bb/Let_Us_C_-_Yashwant_Kanetkar.zip.htmlYou can also learn C from the online tutorial available at internet. The good one is at ;
http://www.learn-programming.za.net/programming_c_learn01.html

http://cprog.tomsweb.net/

http://www.cprogramming.com
http://cplus.about.com/od/learningc/Learn_How_to_Write_Programs_in_C.htm

There are also various blogs that can help you in understanding C language.

One thing inportant that you will also need a compiler for C programming or you can say a GUI(Graphical User Interface), in which you will practice your programs and will see the output. There are also many versions of C including Borland C, Turbo C, Visual C etc. but we are talking about Turbo C more commonly known as "TC". This compiler can be downloaded from the link below;
http://webcourse.cs.technion.ac.il/234112/Winter2004-2005/en/ho_Download%20Turbo-C.html

One thing must be kept in mind that there is different between programming for computers applications and programming for MCU applications. You will see this difference when you will start your practical work. But one might ask why to learn C? Can we start MCU programming directly? The answer is that starting MCU programming at beginner level may be difficult, if one dont know the basis of C i.e. what are variables, constants, etc. then it would be very difficult to start programming directly in MCU. Also learning C from the above mentioned book is so easy that even a fresh person can easily learn this language.

8051 Microcontroller ebook download free

2011-09-13T01:03:00.000-07:00

The 8051 Microcontroller and Embeded System;
Author= Muhammad Ali Mazidi, Janice Gillispie Mazidi
Indeed this is one of the best book you can find about the MCUs. This book is very helpful for beginners. It gives a deep understanding of the 8051 MCU. This book is more useful for Assembly language programming as all the programs given are in Assembly language. Still this book is the simplest and best to start MCU programing.

Download Link;
http://rapidshare.com/files/123384331/The_8051_Microcontroller_and_Embedded_Systems.rar.html
Password= mbandala

The Final Word on 8051;
Author= Matthew Chapman
This book is good reference book. It will not take you in detail of MCU programming instead it gives you introduction about 8051 hardware, C, serial port, compiler and linker.

Download Link;
http://rapidshare.com/files/123384695/The_Final_Word_on_the_8051.rar.html
Password= mbandala

Programming Embeded Systems;
Author= Micheal J. Pont
This is a very simple book. Indeed a good point to start MCU programming.

Download Link;
http://rapidshare.com/files/123384286/Programming_Embedded_System_I.rar.html
Password= mbandala

Exploring C for Microcontrollers (A Hands on Approach);
Author= Jivan S. Parab
This is great bookwhich give you insight about the MCUs, IDE, interfacing with LED, hyper terminal, and different other applications.

Download Link;
http://rapidshare.com/files/123383693/Exploring_C_for_Microcontrollers_-_A_Hands_on_Approach.rar.html
Password= mbandala

C and the 8051;
Author= Schultz
This is also a good book for C programmers. This book is very detailed and you can search almost every topic from this book.

Download Link;
http://rapidshare.com/files/123383502/C_and_the_8051.rar.html
Password= mbandala

C Programming for Embeded System;
Author= Kirk Zurell
Useful for understanding how to program the MCU in C language. At the end some sample programs are given.

Download Link;
http://rapidshare.com/files/8490707/B39E6315-B741-4E89-838C-570D536B4DB5.rar.htm
Password= books_for_all

Embeded C;
Author= Micheal J. Pont
Making 8051 MCUs in focus this book is a one fo the best and most popular book and also very simple. It teaches you MCU programming in C from "Hello" program to applications.

Download Link;
http://rapidshare.com/files/123383633/Embedded_C_tutorial_-_8051.rar.html
Password= mbandala

Programming Microcontrollers in C;
Author= Ted Van Sickle
This is also a great book to read. In this book as in other books, you will find basics of C programming for MCUs as well as some advance topics including MCORE and RISC. It introduces microcontrollers and describes their programming environment, offering tips on coding for microcontrollers

Download Link;
http://rapidshare.de/files/21352479/VAN_SICKLE__T.__2001_._Programming_Microcontrollers_in_C__2nd_ed._.rar

System Design and the 8051;
Author= Marcus O. Durham
This book will not explain you each and every instruction in C but it gives you general idea of every thing you need in MCU programming.

Download Link;
http://rapidshare.com/files/123384286/Programming_Embedded_System_I.rar.html
Password= mbandala

The 8051 Microcontrollers;
Author= Kenneth J. Ayala

This is one of the best book written for 8051 lovers. This book covers topic from MCUs, 8051 architecture, programming and their applications. But the problem is that this programs are in Assembly lnguage but still you can get alot of help in understanding the MCUs.

Download Link;
http://rapidshare.com/files/123384377/The_8051_Microcontroller_Architecture__Programming__and_Applications.rar.html
Password= mbandala

The 8051 Microcontrollers;
Author= I. Scott MacKenzi

This is also a good book including 8051 architecture, timers, counters, with Assembly programs on various applications including serial communication and interrupt handling.

Download Link;
http://rapidshare.com/files/21615321/The_8051_Microcontroller_Book_by_Scott_Mackenzie.pdf.html

Programming Embedded Systems in C and C++
Author= Michael Bar
Download Link;
http://www.megaupload.com/?d=I03TGLVE

Microcontroller projects in C for the 8051;
Author= Dogan Ibrahim.
This is a great book for those people who want to start the MCU based projects without going in to details of programming, yet it gives the introduction to C and then application like LED, Buzzer, Temprature and serial communication.

Download Link;
http://www.ebook3000.com/Microcontroller-Projects-in-C-for-the-8051_22925.html

8051 Microcontroller for beginners video lectures

2011-09-13T01:01:00.000-07:00

To use the AT89C51 to develop a microcontroller-based system requires a ROM burner that supports flash memory; however, a ROM eraser is not needed. Notice that in flash memory you must erase the entire contents of ROM in order to program it again. This erasing of flash is done by the PROM burner itself .

Every microcontroller contains flags that may be used for testing the outcome of an instruction's execution. For example, the carry flag may be used to test the outcome of an 8-bit addition to see if the result is greater than 255.
Port 0; is a dual-purpose port on pins 32-39 of the 8051 1C. In minimum – component designs, it is used as a general purpose I/O Port. For larger designs with external memory, it becomes a multiplexed address and data bus.

Port 1; is a dedicated I/O port on pins 1-8. The pins, designated as P1.0. P1.1. P1.2 etc. are available for interfacing to external devices as required. No alternate functions are as signed for Port 1 pins; thus they are used solely for interfacing to external devices. Exceptions are the 8032/8052 ICs. Which use P1.0 and P1.1 either as I/O lines or as external in outs to the third timer.

Port 2; (pints 21-28) is a dual – purpose port serving as general purpose I/O, or as the high byte of the address bus for designs with external code memory or more than 256 bytes of external data memory.

Port 3;is a dual – purpose port on pins 10-17. As well as general – purpose I/O, these pins are multifunctional with each having an alternate purpose related to special features of the 8051).

Now coming to the other pin functions.

PSEN;This is an output pin. PSEN stands for “program store enable.” In an 8031-based system in which an external ROM holds the program code, this pin is connected to the OE pin of the ROM.
VCC;Pin 40 provides supply voltage to the chip. The voltage source is +5V.

GND; Pin 20 is the Ground pin.

XTAL1 and XTAL2;The 8051 has an on-chip oscillator but requires an external clock to run it. Most often a quartz crystal oscillator is connected to inputs XTALI (pin 19) and XTAL2 (pin 18). The quartz crystal oscillator connected to XTAL1 AND XTAL2 also needs two capacitors of 30 pF value.

The microcontroller online lecture

2011-09-13T00:51:00.000-07:00

This site introduces students, educators, and hobbyists to the capabilities of a powerful modern microcontroller, the Microchip PIC24.

Microcontrollers: From Assembly Language to C Using the PIC24 Family covers a broad range of topics in a straightforward, conversational style accessible to students and hobbyists. Topics include PIC24 assembly language programming and hardware interfacing using the C language. A video tutorials page is also available that contains selected topics from the book.

The ECE3724 course on microprocessors features on-line lecture notes and lab experiments including experiments with a digital thermometer and fan speed control.

Electronic circuit design, Schematic diagrams, KVL, KCL, sign conventions, Power and energy, circuit components, Resistive circuits: series, parallel, dividers,

How to Increase Your Wi-Fi Signal

2011-09-13T00:43:00.000-07:00

Tear off some foil in the shape of a rectangle, give it a curve and then place the foil behind the antenna of your router. This will reflect the wireless signals into your preferred directions.

If the router is mounted on a wall, you can make holes in the Aluminium foil and insert it inside the antennas as shown in the following video.

If you are away from your home base and want to connect to an unprotected wireless signal, this short video provides some great tips to help you do this. By using your cell phone, laptop, an ethernet cable or a salad bowl with aluminum foil, you can increase network availability and extend your wireless range. Now I can finally go set up shop with my laptop in that beautiful park near my house! Yay!
1. use your Ethernet connection which is nor a wireless connection,,,
2. wrapping up your cellphone want do any good to any signal ....
3. ... and for sure not by putting it in your salad bowl.

so if you really want to increase your wifi signal you can just google for "how to extend wireless range" and you'll get real ideas (common is reflecting back the AP signal by putting aluminum foil behind the antenna)

USB 4Gb construction usb data transfer cable homemade

2011-09-13T00:36:00.000-07:00

Universal Serial Bus is a high speed connectivity standard enabling
simple Plug and Play connections to devices such as modems, digital
cameras, camcorders, keyboards and mice. The standard is being
supported by many leading suppliers of computers and peripherals.
An advantage of USB is that the devices are hot pluggable meaning
live connection/disconnection without data loss or interruption.
Devices manufactured to the current USB Revision 2.0 specification
are backward compatible with version 1.1.
The USB specification requires a host system to be equipped with
an A type jack. The B type jack is typically found on peripheral
devices requiring detachable cables. Therefore, detachable USB
cables are configured as A to B male combination, preventing
improper bus configurations and topology miswiring.

Connectors
Type A Plug
(4 position)
Type A Jack
(4 position)
Type B Plug
(4 position)
Type B Jack
(4 position)
Mini Type B Plug
(4 position)
Mini Type B Jack
(4 position)
Topology
Mini Type B Plug
(5 position)
Mini Type B Jack
(5 position)

usb data transfer cable homemade

Basic Electronics video Lecture watch online

2011-09-13T00:31:00.000-07:00

MULTIMETERA Multimeter is indeed a multiple meter. It an measure dc and ac voltages, currents and in addition resistances!In some recent DMMs we can measure even frequency, capacitance, etc. Two long probes are used to connect the DMM to a circuit during a measurement.The central dial knob is rotated to choose the parameter we wish to measure. When not in use we keep the knob in OFF position.

SOLDERLESS BREADBOARD:-
How to check the breadboard for this arrangement of connectivitybelow. We can do that simply by using a DigitalMultimeter(DMM) and a couple f wires. Insert the wires into the two holesbetween which you want to heck the electrical continuity. Use the DMM in resistance mode and connect the two probes of the DMM to two strips of wires. If the resistance shown is Zero thenthey are connected. If the DMM reads high resistance then the two points are disconnected electrically (infinite resistance or open).
Resistors, Capacitors,etc., are known as passive components because they can only attenuate the electrical voltage and signals And cannot amplify. Whereas deviceslike transistors, operational amplifier(Op Amp) can amplify or increase the amplitude And energy associated with the signals. Hence the transistors and OpAmp come under active devices.

Remote Sales Terminal GSM Networking

2011-08-14T09:31:00.001-07:00

The main objective of the application is to automate the existing system of manually maintain the records of the counter sales, purchases, reorder levels, Supplier and Customer monetary positions and other related transactions made at the counter. Same other ways gsm is used get the status of the sales happened on the counter without the intervention of the operator. Most companies have the problem of measuring the performance of their sales staff because each salesperson is different and they work in varied methods.Pic microcontroller and gsm modem will work togetther to form the system where at a particular stage it will sends the sms to the senior sales officer about the sales of particular time periods.Effective results from measuring the performance of each salesperson should have a purpose: to help them be more profitable to your company.The project INVENTORY MANAGEMENT SYSTEM FOR STORE is software developed for established store.
To manage all operations of the show room this project is developed. It will have all the basic module to manage the show room operations.This application can be used by any store to automate the process of manually maintaining the records related to the subject of maintaining the stock and liquid flows.
The main aim of the project is to provide utility to maintain day to day operations of apartments. This software help them to store all transactions electronically in a system, which in turn saves lot time, money and energy.

circuit électrique lampe voltmètre wattmètre,lcd programing,+circuit diagram of ammeter,16f628a 5 digit led,circuit diagram of voltmeter,lcd audio sub controller homemade,usb data transfer cable homemade

Public Announcement PA system

2011-08-14T09:30:00.002-07:00

Announcemnt systems are rapidly getting popularity these days becuase no body has time to read news paper or attend any meeting. In the school or college students may get their result announcemnt on the cell phone or any important information as an accounement. Basically it is the system used PIC Microcontroller send sms to the subscriber about any particular annoucement. System reads the sms and announce this on the speaker. This way speaker can send his message through sms to the targetted audience.
The purpose of this project is to light an LED at a central monitoring station that corresponds to a specific speaker, if the speaker is still connected properly in a public address system. The following design requirements were set at the beginning of this project.

• To be compatible with existing public address system hardware. Competing technologies require specific audio amplifiers with network interface cards.
• Capable of being installed in an existing two wire public address system. Installing additional wiring to each speaker would be very costly.
• No batteries to be installed at each speaker, Maintenance cost of replacing batteries at each speaker would be very costly.
The topic of supervision of public address systems due to fire and building codes is becoming more prevalent as codes become more stringent on the topic.The basic design concept is to install monitoring boxes at the end of each string of speakers which would be tuned to 20 kHz. In the absence of an announcement taking place a 20 kHz pilot tone would be sent out onto the lines and the impedance would be measured at the amplifier. If the current changed by ±5mA indicating a fault in the line an alarm would be sent to a GUI via cobranet. This design would make sense if all the speakers were wired in a straight line .The basic operation of the speaker supervision test follows this sequence:

1. Basic Stamp powered on begins test, Power also sent to Speaker Modules.
2. Basic Stamp outputs digital high on PO changing state of DPDT Relay #1 allowing the Basic Stamp to cease the line.
3. Basis Stamp outputs Speaker Module #1 frequency, if still connected properly returns digital high on speaker supervision line.
4. Basic Stamp receives digital high, activates LED that corresponds to speaker #1
5. Basis Stamp outputs Speaker Module #2 frequency, if still connected properly returns digital high on speaker supervision line.
6. Basic Stamp receives digital high, activates LED that corresponds to Speaker #2
7. Basis Stamp outputs Speaker Module #3 frequency, if still connected properly returns digital high on speaker supervision line.
8. Basic Stamp receives digital high, activates LED that corresponds to Speaker #3
9. Test Complete, Basic Stamp powered down therefore outputting digital low on PO changing state of DPDT Relay #1 allowing the public address system audio amplifier to cease the line.
This relay is used to switch from the audio amplifier having control of the line to the BS2 controlling the line. Once the speaker supervision test is initiated using the pushbutton on the BS2, Pin PO will be set using the high command which will automatically place the pin in output mode and place a +5 voltage level on the line. This command will turn Transistor #1 on allowing current to pass through the coil of the relay creating a magnetic field which will switch the state of both poles of the relay. Public address system with multi-point microphone input facilities and provisions for background music.
.1 Microphones, Generally: dynamic, omni-directional and as follows:

.1 Output Level at 1 kHz, Open Circuit: 81 db.
.2 Power Level: 60 db.
.3 E1A Sensitivity: 153 db.

.2 Wall-Mounted Microphones:

.1 Mounting: flush, on standard single gang wall box, rubber shock mounted.
.2 Finish: brushed chrome.
.3 Switch: double pole, double throw pushbutton for push to talk and line shorting.
.4 Frequency response: 100-10,000 Hz.
.5 Impedance: 150 to 200 ohms,

GPS Interface In GSM Networks

2011-08-14T09:30:00.000-07:00

satellite communications services to mobile users When gps and gsm works together forms very powerful combination of system. GSM is used to send and receive sms and GPS is used to get the geo location of the person. GPS tracks the current geographical location of the user and sends the information to the pic microcontroller and then pic microcontroller sends the longi and leti to the system attached with the computer. This way both gsm and gps works together and do their own job perfectly. the cost of the project is very high because hardware used gps and gsm are very costly.Thuraya mobile satellite system became operational, offering satellite phone service throughout the Middle East, Northern Africa, Europe, India and parts of Asia. Building upon the circuit-switched system infrastructure and GMR-1 Air Interface, Hughes Network Systems is developing a packet data system for Inmarsat, the Regional Broadband Global Area Network Project (BGAN-R).While the upper layer protocols are virtually unchanged from the GPRS standard, several modifications are implemented for the MAC/RLC protocol layer to address the delay inherent in the Geo-Mobile satellite system. GPRS is classified as a 2.5G (or 2G Plus) technology because it builds upon existing network infrastructure whereas with 3G networks it normally requires building an entirely new network. In order to compete against 3G networks, therefore, North- American operators have been looking to GPRS to provide high speed data links. Hence, manufacturers have been working on a related technology known as EDGE (Enhanced Data for Global Evolution). In order to compete with 3G, EDGE must offer links running at 384 Kbit/s and originally this equated to running GPRS three times faster. However, because GPRS has proved much slower than expected, it now needs to be seven times faster.
The task of defining GPRS has been the responsibility of the Special Mobile Group (SMG) - part of the 3GPP initiative (3rd Generation Partnership Project). Rather than wait for the final version of the SMG standard some manufacturers decided to go with GPRS handsets which conformed to an earlier version of the specifications known as SMG29. This basically offers two 'down' channels and a single 'up' channel. In practice each channel is offering around 12-13 Kbit/s so the top speeds works out to be around 26 Kbit/s. Most experts agree, however that full interoperability between products will come with SMG 31. This is capable of offering four 'down' channels which equates to a top speed of around 52 Kbit/s - the same as a high speed (V.90) landline modem.There are three principal types of synchronization that are of importance. Each particular application may have different needs and it is necessary to ensure that the transport network be capable of providing this functionality or the network operator must provide for alternate methods. The three synchronization categories are:
a. Frequency synchronization
b. Phase synchronization
c. Time synchronization

Frequency synchronization relates to the alignment of clocks in frequency, a process that is also referred to as syntonization. Phase synchronization implies that the two clocks are aligned in phase, a process that also referred to as relative-time synchronization. Time synchronization is also referred to as time-of-day synchronization or wall-clock synchronization where the clocks in question are traceable to a common, universal, time-base such as UTC. Note that if two clocks are synchronized in time/phase then they are also synchronized in frequency. For some applications frequency synchronization may be adequate; for others a combination of frequency and time/phase may be required. For some applications the source of time/timing may be specified and for others the source could be any one of a set of (master) clocks.
The three use case categories considered here are:
1. Wireless
2. Infrastructure
3. Media Gateway

Within this general use-case category there are several applications of importance. Some of these require just frequency information and others require time-of-day and others require phase. The application, from the viewpoint of timing, is to deliver the appropriate timing information to a base station cell signaling flow chart reception

Automatic Image Transfer system Through SMS gsm

2011-08-14T09:29:00.001-07:00

When in remote area you want to capture the photo of any location suppose you are away from your home and want to capture the photo of your drawing room and want it back to your cell phone as an attachment this project is for you. Using PIC Microcontroller and TTL based camera module is attached with GSM modem see happening and working as desired mode. User sends the sms to see the latest photos to the system and system caputre the current photo and sends back to the user. This projects may be costly then other due to camera module which costs more than 5000 rs.The aim of this CR is to introduce additional requirements dedicated to the bearer independent data transfer feature.
This functionality enables the SIM to establish a data channel with a Server on the preferred available bearer and then to exchange data over this channel independently of the previously selected bearer.
To establish a GPRS communication the ME shall support the followings requirements
• Manage data flow control over the link
• Provide the SIM with ME’s GPRS capability at power on and/or later.

The support of anonymous GPRS and GPRS SMS is left for further study
The introduction of wireless communication has allowed many people around the world to live their lives and conduct business in ways that were never before possible. Millions of cellular subscribers have become accustomed to always having a telephone with them wherever they go. Now, businesses are wanting to be able to connect to the office when they are out of the office so they can check their email, search on the Internet, access company files, send faxes and data whenever and wherever it is needed. Currently, there are numerous wireless data services available, but a new technology, General Packet Radio Service, offers much excitement to consumers. GPRS (General Packet Radio Service) is a step between GSM and 3G cellular networks. GPRS offers faster data transmission via a GSM network within a range 9.6Kbits to 115Kbits. This new technology makes it possible for users to make telephone calls and transmit data at the same time. (For example, if you have a mobile phone using GPRS, you will be able to simultaneously make calls and receive e-mail massages.) This paper will entail an intermediate language and serves to introduce this technology to both the developer and end-user alike. I discuss the underlying architecture and basic functionality of GPRS followed by its many applications.Before introduction of GPRS, the radio capacity was used for calls and data transmission within the GSM (Global System Mobile) network in a rather inefficient way. For data transmission the entire channel was occupied and was thus insufficiently used. With the GPRS technology, the channel is used more efficiently owing to the possibility of more than one user sharing the same channel. GPRS telephones user several channels for data transfer thus facilitating greater transfer speeds. The GPRS infrastructure and mobile phones support a data transmission speed of up to 13.4Kbits per channel.GPRS makes sending and receiving small bursts of data, such as email and web browsing, as well as large volumes of data over a mobile telephone network possible. A simple way to understand packet switching is to relate it to a jigsaw puzzle. Image how you buy a complete image or picture that has been divided up into many pieces and then placed in a box. You purchase the puzzle and reassemble it to form the original image. Before the information is sent, it is split up into separate packets and it is then reassembled at the receivers end. Some of the basic/prerequisite knowledge of GPRS follows.

Developement of Remote Appliance Control through SMS and DAQ

2011-08-14T09:28:00.002-07:00

Same other ways gsm is used get the status of the sales happened on the counter without the intervention of the operator. Pic microcontroller and gsm modem will work togetther to form the system where at a particular stage it will sends the sms to the senior sales officer about the sales of particular time periods.
GPRS Telephones
-Due to the fact that more than one channel is used for downlink, the GPRS mobile phones make possible greater data transmission speeds. There are several types of phones with regard to the number of channels they use for data transmission...
• Type 2+1 – two downlink channels and one uplink data transmission channel
• Type 3+1 – three downlink channels and one uplink data transmission channel
• Type 4+1 – four downlink channels and one uplink data transmission channel
-The GPRS mobile phones can be classified into the following three classes in terms of the possibility of simultaneous calls (via GSM) and data transmission (via GPRS).
• Class A – Simultaneous calls (via GSM) and data transmission (via GPRS)
• Class B – Automatic switching between the GSM and the GPRS mode is possible according to telephone settings.
• Class C – Hand operated switching between the GSM and the GPRS mode
GPRS could possibly be the technology that will allow consumers to really begin to pursue the mobile Internet. GPRS is considered one step ahead of HSCSD (High Speed Circuit Switched Data) and a step towards 3G (Third-generation) networks. It is the step to 2.5G for GSM and TDMA (Time Division Multiple Access) service providers.

GPRS is ideal for Wireless Application Protocol (WAP) services because of the cost saving WAP over GPRS bring to mobile operators and cellular consumers. Costs are reduced because GPRS radio resources are only needed while the message is being transferred. For the end user, that means you only pay for the time it takes to download the data and information that you need. For the GSM operator, that means that you will be able to provide high speed Internet access to consumers at a reasonable cost, because you will bill mobile phone users for only the amount of data that they transfer rather than billing them for the length of them that they are connected to the network.

SMS Based Weather station

2011-08-14T09:28:00.000-07:00

Weather reporting system refers to the system who keeps an eye on changing climate like tepmperature, humidity and gases in the air. PIC Microcontroller based sms based weather reporting systems several sensors are used to collect the current situation of the atmospher and sends sms to the subscriber telling about the weather conditions of that state or region. It requires PIC Microcontroller and gsm modem to send sms. Battery backup can also be used for this purpose in the case of power failure system runs intact.
The name, General Packet Radio Service (GPRS) doesn't convey much information to the non-technical user. Describing it as providing a direct link into the Internet from a GSM phone, is much clearer. GPRS is to mobile networks what ADSL (Asymmetric Digital Subscriber Line) is to fixed telephone networks - the favoured solution for providing fast and inexpensive Internet links.
GPRS will undoubtedly speed up a handset's Internet connection - but it remains to be seen exactly how much speed can be wrung out of the system. GPRS works by amalgamating (aggregating) a number of separate data channels. This is feasible because data is being broken down into small 'packets' which are re-assembled by the receiving handset back into their original format. The catch is that the number of receiving channels does not necessarily have to match the number of sending channels. On the Internet, it is assumed that you want to view more information (such as a complicated Web page) than you want to send (such as a simple Yes or No response). So GPRS is an asymmetric technology because the number of ‘down’ channels used to receive data doesn’t match the number of ‘up’ channels used to send data.
WHAT IS GPRS?

GPRS stands for General Packet Radio Service, and is a relatively low cost technology that offers packet-based radio service and allows data or information to be sent and received across mobile telephone networks.Designed to supplement the existing mobile technologies, like GSM, CDMA, and TDMA etc.

WHAT DOES GPRS DO?

GPRS provides a permanent connection where information can be sent or received immediately as the need arises, subject to radio coverage. No dial-up modem connection is necessary. This is why GPRS users are sometimes referred to be as being anytime-anywhere "always connected".The GPRS tariff structure is based on a fixed cost, dependent on the quantity of data required. In other words customers will be able to fix their operating costs without the concerns of variable billing.

WHY GPRS?

At present circuit switching technique like your telephone line, in order to send or receive emails, transfer files or browse WAP/Web sites.it is first necessary to make a 'data' call. The call is answered by a modem or an ISDN adapter owned either by the network operator itself (such as BT Cellnet) or by an Internet Service Provider (ISP). Next the caller is 'authenticated' by giving a user ID and password and then assigned an Internet address by the ISP or operator. The whole process can take up to sixty seconds or more and even at the end of this procedure the connection is slow - normally a mere 9.6 Kbit/s.

GSM Based Video Surveillance Recorder

2011-08-14T09:27:00.001-07:00

Video surveillance is very common and important these days to safeguard our home and offices. The main advantage of the system is to record the videos 24 hours about the movements of the human beings in the buildings. In these systems cameras are installed every possible location to capture the videos. PIC Microcontroller is the brain of the system to control the GSM modem or device and used to activate or deactivate the system. Using the project we can switch on or swith off the device from remote area by sending sms.With GPRS-enabled mobile phones, services are received faster than with traditional GSM phones. GPRS offers an increase in data throughput rates, so information retrieval and database access is faster, more usable and more convenient. At its best, GPRS is transparent, allowing the user to concentrate on the task in hand rather than on the technology.

To use GPRS, the user will need:
• A subscription to a mobile telephone network that supports GPRS – use of GPRS must be enabled for that user. Automatic access to the GPRS may be allowed by some mobile network operators, others will require a specific opt-in
• Knowledge of how to send and/or receive GPRS information using their specific model of mobile phone, including software and hardware configuration (this creates a customer service requirement)
• A destination to send or receive information through GPRS. (Whereas with SMS this was often another mobile phone, in the case of GPRS, it is likely to be an Internet address, since GPRS is designed to make the Internet fully available to mobile users for the first time.
With packet switching technique GPRS, there is no call. Once the handset is powered on, by pressing a button the user is connected directly to the Internet. The link is only broken when the handset is turned off - hence GPRS is known as an 'always on' connection. The fact that the link is continuous has one major benefit. It enables the ISP/operator to know a handset's Internet address. So messages can be passed directly over the Internet from a PC, for example, down to your handset. Crucially this facility enables the Internet Service Provider to 'push' messages down to your handset - rather like an SMS message. The difference is that with GPRS the link is interactive. That means if you want to respond directly - such as instruct your broker to sell 500 shares - you can. One of the major criticisms aimed at WAP is that it lacked support for 'push' technologies. This failing has effectively been rectified via an update to the WAP standards (version 1.2) and the introduction of GPRS enabled WAP handsets.

GSM Based Security System for Home and Offices

2011-08-14T09:26:00.000-07:00

GSM based security system are very common theses days. The motive of these projects to guard and keep an eye on the home or any office, banks. Several sensors are attached with PIC Microcontrollers like motion sensors, gas sensors, infrared sensors basically this is the network of sensors to see the things happening. When any action or movement is detected by the sensor then the pic microcontroller based security system sends sms to the owner of the home or office about the detection in the premises.This project has analyzed the situation of existent fire alarm systems and has proposed a new method of connecting local fire alarm controllers to build a much larger and more powerful system, with GSM (Global System for Mobile Communications) as the communication medium. All these local fire alarm controllers, which work as slave stations, and a central monitor, which works as a master station, are incorporated in the GSM network. Information is transmitted between the master station and slave stations through SMS (Short Message Service). The general structure of the system is presented in this paper. It is a three-hierarchy model and it consists of three subsystems: detecting and controlling subsystem, communication subsystem and central monitor subsystem. The function of each subsystem is explained and the hardware and software details of the communication subsystem are described.

With the rapid urbanization and the emergence of more and more skyscrapers, fire occurs frequently, which not only causes large economic losses, but also endangers people’s lives. To avoid fire disasters, many kinds of fire alarm systems have been explored.
At present, most of the conventional fire alarm systems work separately, without connection with each other. A typical one consists of a MCU as its core, some sensors and control devices. The MCU analyzes the data output by sensors and when it determines there is a fire, it alarms by sound or light and output specified commands to the control devices.
Also a more advanced kind of fire alarm system has been proposed recently. In this kind of fire alarm system, local fire alarm controllers are connected by field bus, such as RS485, CAN, etc, so they can exchange information with each other. This kind of system provides the possibility of remote monitor and control, hierarchical management and communication services, etc. But all these field buses have a limited maximum cable length. For example, the maximum cable length for RS485 specification is 1 200 m. As for CAN, when data rate is below 10 kbps, the maximum cable length is 6.7 kilometers; when data rate is up to 1 Mbps, the cable length cannot exceed 40 m. So this kind of system can only be used in small-sized or medium-sized areas where local fire alarm controls are not very far apart, such as a floor, a single building, or several nearby buildings.
However, in large-sized areas, as a campus, a district with many buildings or even a city, there is no appropriate method of network connection yet. This paper has advanced an innovative GSM-based fire alarm system. All the local fire alarm controllers and a central monitor are linked wirelessly in the GSM network and information is transmitted through SMS.
This paper is structured as follows: in the next section, the general structure of the GSM-based fire alarm system is presented and the function of each subsystem is explained; and then the hardware and software details of one of its subsystems – the communication subsystem are described.

Development of online ECG Picture Messaging system gsm

2011-08-14T09:25:00.001-07:00

In the medical devices ECG is the imporant device. The purpose of this device to check the heart and pulse rate of the patient. The purpose of this project using PIC Microcontroller to keep an eye on the ECG of the patient and sends the report to the receipient system to see the status. It is the automated system to record the ECG of any patient and keeps the record when something unusual then it sends the report as the sms to the concerned person. So the senior level staff need not to see only one patient at a time.
The detecting and controlling subsystem is almost the same as that of the conventional distributed fire alarm systems. As shown in Figure 1, the detecting and controlling subsystem is composed of many nodes (node 1 to node n in Fig.1) and a central MCU (MCU 1 in Figure 1). The nodes all have the same structure as node 1. Each node includes three parts: a MCU, sensors and control devices. The sensors can be fog sensors, temperature sensors and relative humidity sensors, etc. Sensors sample the environmental variables and pass the parameters to the MCU in each node. The control devices include valves and taps, etc. They are started and stopped by signals output by the MCU in each node. It should be pointed out that the MCU in each node doesn’t have “intelligence”, i.e. it doesn’t analyze parameters or determine whether a fire has occurred. It’s the central MCU (i.e. MCU 1 in one node) that has the “intelligence”. These nodes are set in a relatively small area, for example, one in each room. Since these nodes are not very far apart, they are connected by RS485, together with MCU 1. MCU 1 works as the master station, and each node has a unique slave address on the bus. MCU 1 polls parameters from each node and makes a comprehensive analysis to determine whether there is a fire or not. If a fire occurs, it will command corresponding nodes to give off alarm signals, such as sound or light, and start the valves or taps.
This subsystem is in the lowest hierarchy of the three-hierarchy model. The accuracy and real time processing can be guaranteed by RS485 bus.
When a new service is introduced, there are a number of stages before it becomes established. GPRS service developments will include standardization, infrastructure development, network trials, contracts placed, network roll out, availability of terminals, application development, and so on.

Process Control system through SMS using microcontrollers

2011-08-14T09:24:00.003-07:00

Process controll is the system where so many processes are running in the industry to get a particular job done. Example in the cold storage where a operator has to control the temperature manually when see the temperature is falling of getting high. This way all other processes happens to complete a particular job. So instead of manual doing all this. PiC microcontroller has the solution to creat process controls system using Pic microcontroller. Attaching required hardware like temperature sensors and other actuators we can build slef run systems by the PIC Microcontrollers

Monitoring System for Railway Accident

2011-08-14T09:24:00.001-07:00

Every day we listen on radio and read in the newspaper about the railway accidents happening in the country. It is very sad because people loose their life and loss of economics of the country. So the purpose of this project is to inform to the sernior staff of the railway about the status of the physical parts of the railway like tracks, engine status, signaling and other vital information which leads to the railway accident. Project use PiC microcrocontroller and gsm mobile or modem to send or receive msgs and inform about any kind of failure.