Prepaid energy meter with gsm interface by anjalibajipai

Prepaid Energy Meter with GSM Interface

Introduction ď&#x192;&#x2DC; The project has been introduced in the power sector to effectively record the units consumed for billing purposes and also monitor several other factors to reduce power theft and minimize losses that occurs due to conventional electromechanical energy meters. This is a multipurpose project that integrates all the functions including a prepaid billing arrangement and automatic message sending system to the utility company.

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Prepaid Energy Meter with GSM Interface

Block Diagram

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Prepaid Energy Meter with GSM Interface

Hardware Requirements         

Microcontroller (AT89C52/S52) Max232 GSM module LCD(16x2) LED Crystal Oscillator Resistors Capacitors Diodes

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Prepaid Energy Meter with GSM Interface

Hardware Requirements      

Transformer Regulator Opto Isolator Energy Meter Lamp push buttons.

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Prepaid Energy Meter with GSM Interface

Software Requirements  Keil compiler  Languages: Embedded C or Assembly

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Prepaid Energy Meter with GSM Interface

Power Supply ď&#x192;&#x2DC; A power supply is an electronic device that supplies electric energy to an electrical load.

Bridge rectifier

230 V AC 50 Hz

5v Regulator

5V DC 12V step down transformer

Filter(470Âľf)

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Prepaid Energy Meter with GSM Interface

Power Supply ď&#x192;&#x2DC; The primary function of a power supply is to convert one form of electrical energy to another and, as a result, power supplies are sometimes referred to as electric power converters.

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Prepaid Energy Meter with GSM Interface

Power Supply  A DC Power Supply Unit (commonly called a PSU) deriving power from the AC mains (line) supply performs a number of tasks: • It changes (in most cases reduces) the level of supply to a value suitable for driving the load circuit. • It produces a DC supply from the mains (or line) supply AC sine wave. • It prevents any AC from appearing at the supply output.

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Prepaid Energy Meter with GSM Interface

Parts of a Power Supply  The output voltage is kept at a constant level, independent of changes in: •

The AC supply voltage at the supply input.

•

The Load current drawn from the supply output.

•

Temperature.

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Prepaid Energy Meter with GSM Interface

Energy Meter  An energy or electric meter is a device that measures the amount of electrical  Energy consumed by a residence, business, or an electrically-powered device.  Electric meters are typically calibrated in billing units, the most common one being the kilowatt hour.  Periodic readings of electric meters establish billing cycles and energy used during a cycle.

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Prepaid Energy Meter with GSM Interface

MICROCONTROLLER  It is a smaller computer  Has on-chip RAM, ROM, I/O ports. etc..

CPU

I/O Port

RAM ROM Serial Timer COM Port

A single chip Microcontroller

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Prepaid Energy Meter with GSM Interface Internal Structure af A Micro Controller

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Prepaid Energy Meter with GSM Interface

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Prepaid Energy Meter with GSM Interface

Microcontroller AT89S51/52  Microcontroller AT 89S51 IC has several benefits and advantages, including highlevel constraints, external components hardware less, ease of programming.  And cost-efficient. AT 89S51 IC has an internal program that is easy to remove and re-programmed over and over - again.  In this plane AT 89S51 IC serves as the central control of all aircraft activity. Starting from the timer to control the length of the electrode work.  In this plane AT 89S51 IC is also used as modifiers for the thermal sensor temperature is converted in units of mineral content that is displayed in the form of seven segment displays.

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Prepaid Energy Meter with GSM Interface

Features of AT89S51/52  Compatible with MCS®-51 Products  8K Bytes of In-System Programmable (ISP) Flash Memory  Endurance: 10,000 Write/Erase Cycles  4.0V to 5.5V Operating Range  Fully Static Operation: 0 Hz to 33 MHz  256 x 8-bit Internal RAM  32 Programmable I/O Lines

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Prepaid Energy Meter with GSM Interface

Features of AT89S51/52  32 Programmable I/O Lines  Three 16-bit Timer/Counters  Eight Interrupt Sources  Full Duplex UART Serial Channel  Interrupt Recovery from Power-down Mode  Watchdog Timer  Dual Data Pointer

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Prepaid Energy Meter with GSM Interface

IR LED  An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays in the range of 760 nm wavelength.  Such LEDs are usually made of gallium arsenide or aluminum gallium arsenide.  They, along with IR receivers, are commonly used as sensors.  The appearance is same as a common LED.

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Prepaid Energy Meter with GSM Interface

IR LED  Since the human eye cannot see the infrared radiations.  It is not possible for a person to identify whether the IR LED is working or not, unlike a common LED.  To overcome this problem, the camera on a cell phone can be used.  The camera can show us the IR rays being emanated from the IR LED in a circuit.

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Prepaid Energy Meter with GSM Interface

Photo Diode ď&#x192;&#x2DC; A photodiode is a type of photo detector capable of converting light into either current or voltage, depending upon the mode of operation. ď&#x192;&#x2DC; Photodiodes are similar to regular semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-rays) or packaged with a window or optical fibred connection to allow light to reach the sensitive part of the device.

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Prepaid Energy Meter with GSM Interface

BC547  The BC547 transistor is an NPN Epitaxial Silicon Transistor.  The BC547 transistor is a general-purpose transistor in small plastic packages.  It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.  Whenever base is high, then current starts flowing through base and emitter and after that only current will pass from collector to emitter

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Prepaid Energy Meter with GSM Interface

DB9 Connector ď&#x192;&#x2DC; The DB9 (originally DE-9) connector is an analog 9-pin plug of the D-Sub miniature connector family (D-Sub or Sub-D).

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Prepaid Energy Meter with GSM Interface

MAX 232  The MAX232 is an integrated circuit that converts signals from an RS-232serial port to signals suitable for use in TTL compatible digital logic circuits.  The MAX232 is a dual driver/receiver and typically converts the RX, TX, CTS and RTS signals .  When a MAX232 IC receives a TTL level to convert, it changes a TTL Logic 0 to between +3 and +15V, and changes TTL Logic 1 to between -3 to -15V, and vice versa for converting from RS232 to TTL.

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Prepaid Energy Meter with GSM Interface

GSM Communication  The term GSM usually means the GSM standard and protocols in the frequency spectrum around 900MHz. Mobile Station:  The MS is the physical equipment used by a subscriber, most often a normal handheld cellular telephone. Base Transceiver Station:  The BTS comprises the radio transmission and reception devices, and also manages the signal processing related to the air interface.

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Prepaid Energy Meter with GSM Interface

GSM Communication

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Prepaid Energy Meter with GSM Interface

GSM Modem  A GSM modem is a specialized type of modem which accepts a SIM card, and operates over a subscription to a mobile operator, just like a mobile phone.  From the mobile operator perspective, a GSM modem looks just like a mobile phone.  When a GSM modem is connected to a computer, this allows the computer to use the GSM modem to communicate over the mobile network.  While these GSM modems are most frequently used to provide mobile internet connectivity, many of them can also be used for sending and receiving SMS and MMS messages.

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Prepaid Energy Meter with GSM Interface Liquid Crystal Display (LCD) ď&#x192;&#x2DC; If an 8-bit data bus is used the LCD will require 11 data lines (3 control lines plus the 8 lines for the data bus). ď&#x192;&#x2DC; The three control lines are referred to as EN, RS, and RW.

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Prepaid Energy Meter with GSM Interface Liquid Crystal Display (LCD) Diagram

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Prepaid Energy Meter with GSM Interface Working Principle  This is a multipurpose project that integrates all the functions including a prepaid billing arrangement and automatic message sending system to the utility company.  It may please be noted that it is truly not a usable commercial product engaging actual prepaid card but uses a set of switches for understanding the technology implemented behind it.  This project uses an 8051 microcontroller to which a GSM modem is interfaced .  From here the message is sent to the phone number that is auto saved by giving a missed call to the SIM number present in the GSM modem.

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Prepaid Energy Meter with GSM Interface Working Principle  There are a set of pushbuttons, which are used to load, any recharge amount required.  Such arrangement is in lieu of an actual prepaid card for demo purposes.  By pushing those buttons one can easily recharge the amount.  As soon as the microcontroller receives any recharge amount, a switch is set , to deliver power to the load.  Thereafter consumption of the load power is calculated by the energy meter, which is interfaced to the microcontroller through an Optical Isolator IC.

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Prepaid Energy Meter with GSM Interface Working Principle  The microcontroller program then starts to deduct the recharge amount as per the consumption of load power.  Once the recharge amount reaches to zero then the microcontroller cuts the power supply to the load through a relay driven duly by a NPN transistor  And also sends a message to the phone number stored that contains all the billing information.

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Prepaid Energy Meter with GSM Interface

Further Enhancement ď&#x192;&#x2DC; The concept can further be extended by integrating a RFID smartcard where in each card is provided to automatically recharge the amount and send the same information via GSM module to the respective phone number stored.

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Prepaid Energy Meter with GSM Interface

Conclusion ď&#x192;&#x2DC; Prepaid Energy Meter with GSM Interface was designed and implemented. The concept can further be extended by integrating a RFID smartcard wherein each card is provided to automatically recharge the amount and send the same information via GSM module to the respective phone number stored.

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