GSM BASED ENERGY METER BILLING WITH LOAD CONTROL
GSM BASED ENERGY METER BILLING WITH LOAD CONTROL Submitted By
Introduction The main objective of the project is to develop a wireless energy meter and load control. The microcontroller takes the reading from the energy meter and displays the reading on the LCD. The reading of the energy meter is also sent to the cell phone of the user by a message through GSM modem. which also receives commands from any cell phone to control the electrical loads
Contents Introduction Block diagram Hardware requirements Power supply GSM Opto isolator Relay driver Schematic diagram Working of the project Advantages Applications Conclusion
Block diagram
Hardware requirements TRANSFORMER (230 – 12 V AC) VOLTAGE REGULATOR (LM 7805) RECTIFIER FILTER MICROCONTROLLER (AT 89 S 52/AT 89 C 51) GSM COMMUNICATION GSM MODEM ULN 2003 RELAY LED LCD DISPLAY MAX 232 DB 9 CONNECTOR ENERGY METER OPTO COUPLER 1 N 4007 RESISTOR CAPACITOR
Hardware Components description 1. 230 V AC 50 Hz 2. Using In 4007 as Bridge rectifier 12 V step down transformer 3. Capacitors Filter(470µf) 4. 5 v Regulator 5. Relay
6. GSM MODEM 8. Max 2320 7. OPTO-ISOLATOR
8. DB 9 CONNECTOR 10. RESISTOR 9. LED
11. Capacitor
Power supply
Description of power supply ØThe circuit uses standard power supply comprising of a step-down transformer from 230 v to 12 v and 4 diodes forming a Bridge Rectifier that delivers pulsating dc which is then filtered by an electrolytic capacitor of about 470 microf to 100 micro. F. ØThe filtered dc being un regulated IC LM 7805 is used to get 5 v constant at its pin no 3 irrespective of input dc varying from 9 v to 14 v. ØThe regulated 5 volts dc is further filtered by a small electrolytic capacitor of 10 micro f for any noise so generated by the circuit. ØOne LED is connected of this 5 v point in series with a resistor of 330 ohms to the ground i. e. negative voltage to indicate 5 v power supply availability.
Block diagram of mc External interrupts Interrup t Control On-chip ROM for program code Timer/Counter On-chip RAM Timer 1 Timer 0 CPU OSC Bus Control 4 I/O Ports P 0 P 1 P 2 P 3 Address/Data Serial Port Tx. D Rx. D Counter Inputs
Microcontroller(at 89 s 52) • • Compatible with MCS®-51 Products • • 8 K Bytes of In-System Programmable (ISP) Flash Memory • – Endurance: 10, 000 Write/Erase Cycles • • 4. 0 V to 5. 5 V Operating Range • • Fully Static Operation: 0 Hz to 33 MHz • • Three-level Program Memory Lock • • 256 x 8 -bit Internal RAM • • 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 o • Fast Programming Time
PIN DIAGRAM OF AT 89 S 52
GSM COMMUNICATION The term GSM usually means the GSM standard and protocols in the frequency spectrum around 900 MHz. MS - Mobile Station: The MS is the physical equipment used by a subscriber, most often a normal hand-held cellular telephone. BTS -Base Transceiver Station: The BTS comprises the radio transmission and reception devices, and also manages the signal processing related to the air 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.
Relay driver uln 2003 ØThe ULN 2003 is a monolithic high voltage and high current Darlington transistor arrays. ØIt consists of seven NPN Darlington pairs that features high-voltage outputs with commoncathode clamp diode for switching inductive loads. ØThe collector-current rating of a single Darlington pair is 500 m. A. ØThe ULN functions as an inverter. ØIf the logic at input 1 B is high then the output at its corresponding pin 1 C will be low.
Relay ØA relay is an electrically operated switch. ØCurrent flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. ØThe coil current can be on or off so relays have two switch positions and have double throw (changeover) switch contacts as shown in the diagram.
Opto-isolator ØOpto coupler is a 6 pin IC. It is a combination of 1 LED and a transistor ØPin 6 of transistor is not generally used and when light falls on the Base-Emitter junction then it switches and pin 5 goes to zero. 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.
MAX 232 The MAX 232 is an integrated circuit that converts signals from an RS 232 serial port to signals suitable for use in TTL compatible digital logic circuits. The MAX 232 is a dual driver/receiver and typically converts the RX, TX, CTS and RTS signals. When a MAX 232 IC receives a TTL level to convert, it changes a TTL Logic 0 to between +3 and +15 V, and changes TTL Logic 1 to between -3 to -15 V, and vice versa for converting from RS 232 to TTL.
DB 9 CONNECTOR The DB 9 (originally DE-9) connector is an analog 9 -pin plug of the D-Sub miniature connector family (D-Sub or Sub-D).
LIQUID CRYSTAL DISPLAY (LCD) ØMost common LCDs connected to the microcontrollers are 16 x 2 and 20 x 2 displays. ØThis means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively. ØThe standard is referred to as HD 44780 U, which refers to the controller chip which receives data from an external source (and communicates directly with the LCD.
LCD BACKGROUND ØIf 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) ØThe three control lines are referred to as EN, RS, and RW ØEN=Enable (used to tell the LCD that you are sending it data) ØRS=Register Select (When RS is low (0), data is treated as a command) (When RS is High(1), data being sent is text data ) ØR/W=Read/Write (When RW is low (0), the data written to the LCD) (When RW is low (0), the data reading to the LCD)
Software Requirements Ø Keil an ARM Company makes C compilers, macro assemblers, real-time kernels, debuggers, simulators, integrated environments, evaluation boards, and emulators for ARM 7/ARM 9/Cortex-M 3, XC 16 x/ST 10, 251, and 8051 MCU families. • Compilers are programs used to convert a High Level Language to object code. Desktop compilers produce an output object code for the underlying microprocessor, but not for other microprocessors.
Ø i. e the programs written in one of the HLL like ‘C’ will compile the code to run on the system for a particular processor like x 86 (underlying microprocessor in the computer). Ø For example compilers for Dos platform is different from the Compilers for Unix platform So if one wants to define a compiler then compiler is a program that translates source code into object code.
BIBILOGRAPHY Ø “The 8051 Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education. Ø ATMEL 89 S 52 Data Sheets. • www. atmel. com • www. beyondlogic. org • www. wikipedia. org • www. howstuffworks. com • www. alldatasheets. com
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