Prepaid Energy Meter with GSM Interface

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Prepaid Energy Meter with GSM Interface
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Prepaid Energy Meter with GSM Interface
Introduction

• 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

• A power supply is an electronic device that
  supplies electric energy to an electrical load.

5v Regulator
Bridge rectifier
230 V AC 50 Hz
5V DC
Filter(470µf)
12V step down transformer
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Prepaid Energy Meter with GSM Interface
Power Supply

• 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..

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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
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 AT89S51/52

• Microcontroller AT 89S51 IC has several benefits
  and advantages, including high-level 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

• A photodiode is a type of photo detector capable
  of converting light into either current or
  voltage, depending upon the mode of operation.
• 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

• 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 hand-held
  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)

• 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).
• 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

• 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

• 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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