a project report on energy meter monitoring online using wireless transmission gsm modem

ROBO INDIA | Energy Meter monitoring online using wireless Transmission

PROJECT REPORT ON

Energy Meter monitoring online using wireless

transmission


Chapter 1

Introduction

Wireless communication is the transfer of information between two or more points that

are not connected by an electrical conductor.

Here in our project we have used GSM for the wireless communication.

GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a

standard developed by the European Telecommunications Standards Institute (ETSI) to

describe protocols for second generation (2G) digital cellular networks used by mobile

phones. It is the de facto global standard for mobile communications with over 90%

market share, and is available in over 219 countries and territories.


The GSM standard was developed as a replacement for first generation (1G) analog

cellular networks, and originally described a digital, circuit-switched network optimized

for full duplex voice telephony. This was expanded over time to include data

communications, first by circuit-switched transport, then packet data transport via

GPRS (General Packet Radio Services) and EDGE (Enhanced Data rates for GSM

Evolution or EGPRS).

Subsequently, the 3GPP developed third generation (3G) UMTS standards followed by

fourth generation (4G) LTE Advanced standards, which are not part of the ETSI GSM

standard.

"GSM" is a trademark owned by the GSM Association. It may also refer to the initially

most common voice codec used, Full Rate.

In 1981, work began to develop a European standard for digital cellular voice telephony

when the European Conference of Postal and Telecommunications Administrations

(CEPT) created the Groupe Spécial Mobile committee and later provided a permanent

technical support group based in Paris. Five years later, in 1987, 15 representatives

from 13 European countries signed a memorandum of understanding in Copenhagen to

develop and deploy a common cellular telephone system across Europe, and EU rules

were passed to make GSM a mandatory standard. The decision to develop a continental

standard eventually resulted in a unified, open, standard-based network which was

larger than that in the United States. In 1989, the Groupe Spécial Mobile committee was

transferred from CEPT to the European Telecommunications Standards Institute (ETSI).

In 1987 Europe produced the very first agreed GSM Technical Specification in February.

Ministers from the four big EU countries cemented their political support for GSM with

the Bonn Declaration on Global Information Networks in May and the GSM MoU was

tabled for signature in September. The MoU drew-in mobile operators from across

Europe to pledge to invest in new GSM networks to an ambitious common date. It got

GSM up and running fast.

In this short 37-week period the whole of Europe (countries and industries) had been

brought behind GSM in a rare unity and speed guided by four public officials Armin

Silberhorn (Germany), Stephen Temple (UK), Philippe Dupuis (France), and Renzo Failli


(Italy).[8] In 1989 the Groupe Spécial Mobile committee was transferred from CEPT to

the European Telecommunications Standards Institute (ETSI).

In parallel, France and Germany signed a joint development agreement in 1984 and

were joined by Italy and the UK in 1986. In 1986 the European Commission proposed

reserving the 900 MHz spectrum band for GSM.

Phase I of the GSM specifications were published in 1990. The world's first GSM call was

made by the former Finnish prime minister Harri Holkeri to Kaarina Suonio (mayor in

city of Tampere) on July 1, 1991, on a network built by Telenokia and Siemens and

operated by Radiolinja.[9] The following year in 1992, the first short messaging service

(SMS or "text message") message was sent and Vodafone UK and Telecom Finland

signed the first international roaming agreement.

Work began in 1991 to expand the GSM standard to the 1800 MHz frequency band and

the first 1800 MHz network became operational in the UK by 1993. Also that year,

Telecom Australia became the first network operator to deploy a GSM network outside

Europe and the first practical hand-held GSM mobile phone became available.

In 1995, fax, data and SMS messaging services were launched commercially, the first

1900 MHz GSM network became operational in the United States and GSM subscribers

worldwide exceeded 10 million. Also this year, the GSM Association was formed. Pre-

paid GSM SIM cards were launched in 1996 and worldwide GSM subscribers passed 100

million in 1998.

In 2000, the first commercial GPRS services were launched and the first GPRS

compatible handsets became available for sale. In 2001 the first UMTS (W-CDMA)

network was launched, a 3G technology that is not part of GSM. Worldwide GSM

subscribers exceeded 500 million. In 2002 the first Multimedia Messaging Service

(MMS) were introduced and the first GSM network in the 800 MHz frequency band

became operational. EDGE services first became operational in a network in 2003 and

the number of worldwide GSM subscribers exceeded 1 billion in 2004.

By 2005, GSM networks accounted for more than 75% of the worldwide cellular

network market, serving 1.5 billion subscribers. In 2005 the first HSDPA capable

network also became operational. The first HSUPA network was launched in 2007.


High-Speed Packet Access (HSPA) and its uplink and downlink versions are 3G

technologies, not part of GSM. Worldwide GSM subscribers exceeded two billion in

2008.

The GSM Association estimated in 2010 that technologies defined in the GSM standard

serve 80% of the global mobile market, encompassing more than 5 billion people across

more than 212 countries and territories, making GSM the most ubiquitous of the many

standards for cellular networks.

It is important to note that GSM is a second-generation (2G) standard employing Time-

Division Multiple-Access (TDMA) spectrum-sharing, issued by the European

Telecommunications Standards Institute (ETSI). The GSM standard does not include the

3G UMTS CDMA-based technology nor the 4G LTE OFDMA-based technology standards

issued by the 3GPP.

Macau planned to phase out its 2G GSM networks as of June 4, 2015, making it the first

region to decommission a GSM network.


Chapter 2

Objective

This project reads reading from an energy meter, displays that reading on the LCD

panel. Then it upload these reading on internet via http request. These readings are

easily accessible using a URL . Apart from monitoring it also record data, that too is

online accessible.

The objective of the project is to make the data available through the globe. Different

hardware and software have been used in this project. All these hardware and software

works in a coordination. For making HTTP request and response, online webserver is

used. The server is Linux server. For recording data we have use PHP My Admin data

base management system.


Chapter 3

Methodology

The following block diagram explains working of the system, later we shall discuss all of

the components of the diagram.

Fig.2 | Block diagram


Chapter 4

Programming of hardware controller

This chapter elaborate the programming of hardware controller.

4.1 Introduction to embedded C

Our project is made using embedded programming. The programming language

required for construction of the project is Embedded C. Here in this chapter we will see

the programming of the project and interfacing with the compiler. Before moving ahead

have a look on embedded system.

An embedded system is a computer system with a dedicated function within a larger

mechanical or electrical system, often with real-time computing constraints.It is

embedded as part of a complete device often including hardware and mechanical parts.

By contrast, a general-purpose computer, such as a personal computer (PC), is designed


to be flexible and to meet a wide range of end-user needs. Embedded systems control

many devices in common use today.

Modern embedded systems are often based on microcontrollers (i.e CPUs with

integrated memory and/or peripheral interfaces) but ordinary microprocessors (using

external chips for memory and peripheral interface circuits) are also still common,

especially in more complex systems. In either case, the processor(s) used may be types

ranging from rather general purpose to very specialised in certain class of

computations, or even custom designed for the application at hand. A common standard

class of dedicated processors is the digital signal processor (DSP).

The key characteristic, however, is being dedicated to handle a particular task. Since the

embedded system is dedicated to specific tasks, design engineers can optimize it to

reduce the size and cost of the product and increase the reliability and performance.

Some embedded systems are mass-produced, benefiting from economies of scale.

Physically, embedded systems range from portable devices such as digital watches and

MP3 players, to large stationary installations like traffic lights, factory controllers, and

largely complex systems like hybrid vehicles, MRI, and avionics. Complexity varies from

low, with a single microcontroller chip, to very high with multiple units, peripherals and

networks mounted inside a large chassis or enclosure.

Embedded systems are commonly found in consumer, cooking, industrial, automotive,

medical, commercial and military applications.

Telecommunications systems employ numerous embedded systems from telephone

switches for the network to cell phones at the end-user. Computer networking uses

dedicated routers and network bridges to route data.

Consumer electronics include personal digital assistants (PDAs), mp3 players, mobile

phones, videogame consoles, digital cameras, DVD players, GPS receivers, and printers.

Household appliances, such as microwave ovens, washing machines and dishwashers,

include embedded systems to provide flexibility, efficiency and features. Advanced

HVAC systems use networked thermostats to more accurately and efficiently control

temperature that can change by time of day and season. Home automation uses wired-


and wireless-networking that can be used to control lights, climate, security,

audio/visual, surveillance, etc., all of which use embedded devices for sensing and

controlling.

Transportation systems from flight to automobiles increasingly use embedded systems.

New airplanes contain advanced avionics such as inertial guidance systems and GPS

receivers that also have considerable safety requirements. Various electric motors —

brushless DC motors, induction motors and DC motors — use electric/electronic motor

controllers. Automobiles, electric vehicles, and hybrid vehicles increasingly use

embedded systems to maximize efficiency and reduce pollution. Other automotive

safety systems include anti-lock braking system (ABS), Electronic Stability Control

(ESC/ESP), traction control (TCS) and automatic four-wheel drive.

Medical equipment uses embedded systems for vital signs monitoring, electronic

stethoscopes for amplifying sounds, and various medical imaging (PET, SPECT, CT, MRI)

for non-invasive internal inspections. Embedded systems within medical equipment are

often powered by industrial computers. Embedded systems are used in transportation,

fire safety, safety and security, medical applications and life critical systems, as these

systems can be isolated from hacking and thus, be more reliable.[citation needed] For

fire safety, the systems can be designed to have greater ability to handle higher

temperatures and continue to operate. In dealing with security, the embedded systems

can be self-sufficient and be able to deal with cut electrical and communication systems.

A new class of miniature wireless devices called motes are quickly gaining popularity as

the field of wireless sensor networking is increasing. Wireless sensor networking, WSN,

makes use of miniaturization made possible by advanced IC design to couple full

wireless subsystems to sophisticated sensors, enabling people and companies to

measure a myriad of things in the physical world and act on this information through IT

monitoring and control systems. These motes are completely self-contained, and will

typically run off a battery source for years before the batteries need to be changed or

charged.

Embedded Wi-Fi modules provide a simple means of wirelessly enabling any device

which communicates via a serial port.


4.2 The compiler

Atmel® Studio 6 is the integrated development platform (IDP) for developing and

debugging Atmel ARM® Cortex®-M and Atmel AVR® microcontroller (MCU) based

applications. The Atmel Studio 6 IDP gives you a seamless and easy-to-use environment

to write, build and debug your applications written in C/C++ or assembly code.

Atmel Studio 6 is free of charge and is integrated with the Atmel Software Framework

(ASF)—a large library of free source code with 1,600 ARM and AVR project examples.

ASF strengthens the IDP by providing, in the same environment, access to ready-to-use

code that minimizes much of the low-level design required for projects. Use the IDP for

our wide variety of AVR and ARM Cortex-M processor-based MCUs, including our

broadened portfolio of Atmel SAM3 ARM Cortex-M3 and M4 Flash devices.

With the introduction of Atmel Gallery and Atmel Spaces, Atmel Studio 6 further

simplifies embedded MCU designs to reduce development time and cost. Atmel Gallery

is an online apps store for development tools and embedded software. Atmel Spaces is a

cloud-based collaborative development workspace allowing you to host software and

hardware projects targeting Atmel MCUs.

In summary, standard integrated development environments (IDEs) are suited for

creating new software for an MCU project. By contrast, the Atmel Studio 6 IDP also:

Facilitates reuse of existing software and, by doing so, enables design differentiation.

Supports the product development process with easy access to integrated tools and

software extensions through Atmel Gallery. Reduces time to market by providing

advanced features, an extensible software eco-system, and powerful debug integration.

fig | Atmel Studio


Chapter 5

The parts & Interfacing

Following are the parts of the project.

5.1. Energy Meter

An electricity meter or energy meter is a device that measures the amount of electric

energy consumed by a residence, business, or an electrically powered device.

Electricity meters are typically calibrated in billing units, the most common one being

the kilowatt hour [kWh]. Periodic readings of electricity meters establishes billing

cycles and energy used during a cycle.

In settings when energy savings during certain periods are desired, meters may

measure demand, the maximum use of power in some interval. "Time of day" metering

allows electric rates to be changed during a day, to record usage during peak high-cost


periods and off-peak, lower-cost, periods. Also, in some areas meters have relays for

demand response load shedding during peak load periods.

As commercial use of electric energy spread in the 1880s, it became increasingly

important that an electric energy meter, similar to the then existing gas meters, was

required to properly bill customers for the cost of energy, instead of billing for a fixed

number of lamps per month. Many experimental types of meter were developed. Edison

at first worked on a DC electromechanical meter with a direct reading register, but

instead developed an electrochemical metering system, which used an electrolytic cell

to totalise current consumption. At periodic intervals the plates were removed,

weighed, and the customer billed. The electrochemical meter was labor-intensive to

read and not well received by customers.

An early type of electrochemical meter used in the United Kingdom was the 'Reason'

meter. This consisted of a vertically mounted glass structure with a mercury reservoir

at the top of the meter. As current was drawn from the supply, electrochemical action

transferred the mercury to the bottom of the column. Like all other DC meters, it

recorded ampere-hours. Once the mercury pool was exhausted, the meter became an

open circuit. It was therefore necessary for the consumer to pay for a further supply of

electricity, whereupon, the supplier's agent would unlock the meter from its mounting

and invert it restoring the mercury to the reservoir and the supply.

In 1885 Ferranti offered a mercury motor meter with a register similar to gas meters;

this had the advantage that the consumer could easily read the meter and verify

consumption. The first accurate, recording electricity consumption meter was a DC

meter by Dr Hermann Aron, who patented it in 1883. Hugo Hirst of the British General

Electric Company introduced it commercially into Great Britain from 1888.[3] Unlike

their AC counterparts, DC meters did not measure energy. Instead they measured

charge in ampere-hours. Since the voltage of the supply should remain substantially

constant, the reading of the meter was proportional to actual energy consumed. For

example: if a meter recorded that 100 ampere-hours had been consumed on a 200 volt

supply, then 20 kilowatt-hours of energy had been supplied. Aron's meter recorded the

total charge used over time, and showed it on a series of clock dials.


The first specimen of the AC kilowatt-hour meter produced on the basis of Hungarian

Ottó Bláthy's patent and named after him was presented by the Ganz Works at the

Frankfurt Fair in the autumn of 1889, and the first induction kilowatt-hour meter was

already marketed by the factory at the end of the same year. These were the first

alternating-current watt-hour meters, known by the name of Bláthy-meters. The AC

kilowatt hour meters used at present operate on the same principle as Bláthy's original

invention. Also around 1889, Elihu Thomson of the American General Electric company

developed a recording watt meter (watt-hour meter) based on an ironless commutator

motor. This meter overcame the disadvantages of the electrochemical type and could

operate on either alternating or direct current.

In 1894 Oliver Shallenberger of the Westinghouse Electric Corporation applied the

induction principle previously used only in AC ampere-hour meters to produce a watt-

hour meter of the modern electromechanical form, using an induction disk whose

rotational speed was made proportional to the power in the circuit. The Bláthy meter

was similar to Shallenberger and Thomson meter in that they are two-phase motor

meter. Although the induction meter would only work on alternating current, it

eliminated the delicate and troublesome commutator of the Thomson design.

Shallenberger fell ill and was unable to refine his initial large and heavy design,

although he did also develop a polyphase version.

5.2 Energy Meter Reading

The most common unit of measurement on the electricity meter is the kilowatt hour

[kWh], which is equal to the amount of energy used by a load of one kilowatt over a

period of one hour, or 3,600,000 joules. Some electricity companies use the SI

megajoule instead.

Demand is normally measured in watts, but averaged over a period, most often a

quarter or half hour.

Reactive power is measured in "thousands of volt-ampere reactive-hours", (kvarh). By

convention, a "lagging" or inductive load, such as a motor, will have positive reactive

power. A "leading", or capacitive load, will have negative reactive power.


Volt-amperes measures all power passed through a distribution network, including

reactive and actual. This is equal to the product of root-mean-square volts and amperes.

Distortion of the electric current by loads is measured in several ways. Power factor is

the ratio of resistive (or real power) to volt-amperes. A capacitive load has a leading

power factor, and an inductive load has a lagging power factor. A purely resistive load

(such as a filament lamp, heater or kettle) exhibits a power factor of 1. Current

harmonics are a measure of distortion of the wave form. For example, electronic loads

such as computer power supplies draw their current at the voltage peak to fill their

internal storage elements. This can lead to a significant voltage drop near the supply

voltage peak which shows as a flattening of the voltage waveform. This flattening causes

odd harmonics which are not permissible if they exceed specific limits, as they are not

only wasteful, but may interfere with the operation of other equipment. Harmonic

emissions are mandated by law in EU and other countries to fall within specified limits.

5.3 Electro Mechanical Meter

The most common type of electricity meter is the electromechanical induction watt-

hour meter.

The electromechanical induction meter operates by counting the revolutions of a non-

magnetic, but electrically conductive, metal disc which is made to rotate at a speed

proportional to the power passing through the meter. The number of revolutions is thus

proportional to the energy usage. The voltage coil consumes a small and relatively

constant amount of power, typically around 2 watts which is not registered on the

meter. The current coil similarly consumes a small amount of power in proportion to

the square of the current flowing through it, typically up to a couple of watts at full load,

which is registered on the meter.


Fig | Enegy Meter

The disc is acted upon by two sets of coils, which form, in effect, a two phase induction

motor. One coil is connected in such a way that it produces a magnetic flux in

proportion to the voltage and the other produces a magnetic flux in proportion to the

current. The field of the voltage coil is delayed by 90 degrees, due to the coil's inductive

nature, and calibrated using a lag coil. This produces eddy currents in the disc and the

effect is such that a force is exerted on the disc in proportion to the product of the

instantaneous current, voltage and phase angle (power factor) between them. A

permanent magnet exerts an opposing force proportional to the speed of rotation of the

disc. The equilibrium between these two opposing forces results in the disc rotating at a

speed proportional to the power or rate of energy usage. The disc drives a register


mechanism which counts revolutions, much like the odometer in a car, in order to

render a measurement of the total energy used.

The type of meter described above is used on a single-phase AC supply. Different phase

configurations use additional voltage and current coils.

Three-phase electromechanical induction meter, metering 100 A 240/415 V supply.

Horizontal aluminum rotor disc is visible in center of meter

The disc is supported by a spindle which has a worm gear which drives the register. The

register is a series of dials which record the amount of energy used. The dials may be of

the cyclometer type, an odometer-like display that is easy to read where for each dial a

single digit is shown through a window in the face of the meter, or of the pointer type

where a pointer indicates each digit. With the dial pointer type, adjacent pointers

generally rotate in opposite directions due to the gearing mechanism.

The amount of energy represented by one revolution of the disc is denoted by the

symbol Kh which is given in units of watt-hours per revolution. The value 7.2 is

commonly seen. Using the value of Kh one can determine their power consumption at

any given time by timing the disc with a stopwatch.

P = {{3600 \cdot Kh } \over t}.

Where:

t = time in seconds taken by the disc to complete one revolution,

P = power in watts.

For example, if Kh = 7.2 as above, and one revolution took place in 14.4 seconds, the

power is 1800 watts. This method can be used to determine the power consumption of

household devices by switching them on one by one.

Most domestic electricity meters must be read manually, whether by a representative of

the power company or by the customer. Where the customer reads the meter, the


reading may be supplied to the power company by telephone, post or over the internet.

The electricity company will normally require a visit by a company representative at

least annually in order to verify customer-supplied readings and to make a basic safety

check of the meter.

In an induction type meter, creep is a phenomenon that can adversely affect accuracy,

that occurs when the meter disc rotates continuously with potential applied and the

load terminals open circuited. A test for error due to creep is called a creep test.

5.4 Electronic Meters

Electronic meters display the energy used on an LCD or LED display, and some can also

transmit readings to remote places. In addition to measuring energy used, electronic

meters can also record other parameters of the load and supply such as instantaneous

and maximum rate of usage demands, voltages, power factor and reactive power used

etc. They can also support time-of-day billing, for example, recording the amount of

energy used during on-peak and off-peak hours.

Solid-state design: Solid state electricity meter used in a home in the Netherlands. Basic

block diagram of an electronic energy meter As in the block diagram, the meter has a

power supply, a metering engine, a processing and communication engine (i.e. a

microcontroller), and other add-on modules such as RTC, LCD display, communication

ports/modules and so on. The metering engine is given the voltage and current inputs

and has a voltage reference, samplers and quantisers followed by an ADC section to

yield the digitised equivalents of all the inputs. These inputs are then processed using a

digital signal processor to calculate the various metering parameters such as powers,

energies etc.

The largest source of long-term errors in the meter is drift in the preamp, followed by

the precision of the voltage reference. Both of these vary with temperature as well, and

vary wildly because most meters are outdoors. Characterising and compensating for

these is a major part of meter design.


The processing and communication section has the responsibility of calculating the

various derived quantities from the digital values generated by the metering engine.

This also has the responsibility of communication using various protocols and interface

with other addon modules connected as slaves to it.

RTC and other add-on modules are attached as slaves to the processing and

communication section for various input/output functions. On a modern meter most if

not all of this will be implemented inside the microprocessor, such as the real time clock

(RTC), LCD controller, temperature sensor, memory and analog to digital converters.

5.3 The controller

Robotic arm controller comprises several electronic components. Here we will discuss

the important parts of the circuit.

5.3.1 The microcontroller (Atmega 8)

The ATmega16 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced

RISC architecture. By executing powerful instructions in a single clock cycle, the

ATmega16 achieves throughputs approaching 1 MIPS per MHz allowing the system

designer to optimize power consumption versus processing speed.


Fig.| Atmega 16 Pinout diagram. | PDIP package


Fig.| Atmega 16 Pinout diagram. | TQFP package


Fig.| Atmega 16 Pinout diagram. | MLF package


Fig.31 | Block diagram of Atmega 8


The AVR core combines a rich instruction set with 32 general purpose working

registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU),

allowing two independent registers to be accessed in one single instruction executed in

one clock cycle. The resulting architecture is more code efficient while achieving

throughputs up to ten times faster than conventional CISC microcontrollers. The

ATmega16 provides the following features: 16K bytes of In-System Programmable Flash

Program memory with Read-While-Write capabilities, 512 bytes EEPROM, 1K byte

SRAM, 32 general purpose I/O lines, 32 general purpose working registers, a JTAG

interface for Boundary scan, On-chip Debugging support and programming, three

flexible Timer/Counters with compare modes, Internal and External Interrupts, a serial

programmable USART, a byte oriented Two-wire Serial Interface, an 8-channel, 10-bit

ADC with optional differential input stage with programmable gain (TQFP package

only), a programmable Watchdog Timer with Internal Oscillator, an SPI serial port, and

six software selectable power saving modes. The Idle mode stops the CPU while

allowing the USART, Two-wire interface, A/D Converter, SRAM, Timer/Counters, SPI

port, and interrupt system to continue functioning. The Power-down mode saves the

register contents but freezes the Oscillator, disabling all other chip functions until the

next External Interrupt or Hardware Reset. In Power-save mode, the Asynchronous

Timer continues to run, allowing the user to maintain a timer base while the rest of the

device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules

except Asynchronous Timer and ADC, to minimize switching noise during ADC

conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest

of the device is sleeping. This allows very fast start-up combined with low-power

consumption. In Extended Standby mode, both the main Oscillator and the

Asynchronous Timer continue to run. The device is manufactured using Atmel’s high

density non-volatile memory technology. The On chip ISP Flash allows the program

memory to be reprogrammed in-system through an SPI serial interface, by a

conventional non-volatile memory programmer, or by an On-chip Boot program

running on the AVR core. The boot program can use any interface to download the

application program in the Application Flash memory. Software in the Boot Flash

section will continue to run while the Application Flash section is updated, providing

true Re ad-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-

Programmable Flash on a monolithic chip, the Atmel ATmega16 is a powerful


microcontroller that provides a highly-flexible and cost-effective solution to many

embedded control applications. The ATmega16 AVR is supported with a full suite of

program and system development tools including: C compilers, macro assemblers,

program debugger/simulators, in-circuit emulators, and evaluation kits.

5.3.1.1 Pin Description of ATmega 16.

VCC: Digital supply voltage.

GND: Ground.

Port A (PA7..PA0): Port A serves as the analog inputs to the A/D

Converter. Port A also serves as an 8-bit bi-directional I/O port, if the A/D

Converter is not used. Port pins can provide internal pull-up resistors

(selected for each bit). The Port A output buffers have symmetrical drive

characteristics with both high sink and source capability. When pins PA0

to PA7 are used as inputs and are externally pulled low, they will source

current if the internal pull-up resistors are activated. The Port A pins are

tri-stated when a reset condition becomes active, even if the clock is not

running.

Port B (PB7..PB0): Port B is an 8-bit bi-directional I/O port with internal

pull-up resistors (selected for each bit). The Port B output buffers have

symmetrical drive characteristics with both high sink and source

capability. As inputs, Port B pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port B pins are tri-stated

when a reset condition becomes active, even if the clock is not running.

Port C (PC7..PC0): Port C is an 8-bit bi-directional I/O port with internal

pull-up resistors (selected for each bit). The Port C output buffers have


capability. As inputs, Port C pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port C pins are tri-stated

when a reset condition becomes active, even if the clock is not running. If

the JTAG interface is enabled, the pull-up resistors on pins PC5(TDI),

PC3(TMS) and PC2(TCK) will be activated even if a reset occurs.


Port D (PD7..PD0): Port D is an 8-bit bi-directional I/O port with internal

pull-up resistors (selected for each bit). The Port D output buffers have


capability. As inputs, Port D pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port D pins are tri-stated

when a reset condition becomes active, even if the clock is not running.

RESET: Reset Input. A low level on this pin for longer than the minimum

pulse length will generate a reset, even if the clock is not running.

XTAL1: Input to the inverting Oscillator amplifier and input to the

internal clock operating circuit.

XTAL2: Output from the inverting Oscillator amplifier.

AVCC: AVCC is the supply voltage pin for Port A and the A/D Converter. It

should be externally connected to VCC, even if the ADC is not used. If the

ADC is used, it should be connected to VCC through a low-pass filter.

AREF: AREF is the analog reference pin for the A/D Converter.

5.3 Serial Communication:

Serial communication is a way enables different equipments to communicate with their

outside world. It is called serial because the data bits will be sent in a serial way over a

single line.

A personal computer has a serial port known as communication port or COM Port used

to connect a modem for example or any other device, there could be more than one COM

Port in a PC.

Serial ports are controlled by a special chip called UART (Universal Asynchronous

Receiver Transmitter). Different applications use different pins on the serial port and

this basically depend of the functions required. If we need to connect our PC for

example to some other device by serial port, then we have to read instruction manual

for that device to know how the pins on both sides must be connected and the setting

required.


5.3.1 Advantages of Serial Communication

Serial communication has some advantages over the parallel communication. One of the

advantages is transmission distance, serial link can send data to a remote device more

far then parallel link. Also the cable connection of serial link is simpler then parallel link

and uses less number of wires.

Serial link is used also for Infrared communication, now many devices such as laptops &

printers can communicate via inferred link.

5.3.2 Communication methods

There are two methods for serial communication, Synchronous & Asynchronous.

5.3.2.1 Synchronous serial communication:

In Synchronous serial communication the receiver must know when to “read” the next

bit coming from the sender, this can be achieved by sharing a clock between sender and

receiver.

In most forms of serial Synchronous communication, if there is no data available at a

given time to transmit, a fill character will be sent instead so that data is always being

transmitted. Synchronous communication is usually more efficient because only data

bits are transmitted between sender and receiver, however it will be more costly

because extra wiring and control circuits are required to share a clock signal between

the sender and receiver.

5.3.2.2 Asynchronous serial communication:

Asynchronous transmission allows data to be transmitted without the sender having to

send a clock signal to the receiver. Instead, special bits will be added to each word in

order to synchronize the sending and receiving of the data.

When a word is given to the UART for Asynchronous transmissions, a bit called the

“Start Bit” is added to the beginning of each word that is to be transmitted. The Start Bit


is used to alert the receiver that a word of data is about to be sent, and to force the clock

in the receiver into synchronization with the clock in the transmitter.

Fig.32 | Example of serial data transmission

After the Start Bit, the individual bits of the word of data are sent, each bit in the word is

transmitted for exactly the same amount of time as all of the other bits

When the entire data word has been sent, the transmitter may add a Parity Bit that the

transmitter generates. The Parity Bit may be used by the receiver to perform simple

error checking. Then at least one Stop Bit is sent by the transmitter.

If the Stop Bit does not appear when it is supposed to, the UART considers the entire

word to be garbled and will report a Framing Error.

5.4 GSM Modem

Fig | GSM Modem


SIMCom Wireless Solutions is a subsidiary of SIM Technology Group Ltd (stock code:

2000. H.K). It is a fast growing[citation needed] wireless M2M company, designing and

offering a variety of wireless modules based on GSM/GPRS/EDGE, WCDMA/HSDPA and

TD-SCDMA technical platforms

By partnering with third parties, SIMCom Wireless provides customized design

solutions in M2M, WLL, Mobile Computing, GPS and other applications. SIMCom

Wireless also provides ODM services for customers.

According to ABI Insight report, SIMCom Cellular Module was number two provider of

wireless modules worldwide in 2008 with 20% acquisition of global market share in

2009 the launched SIM 900.

5.5 Server site application

http://scl.fabroll.com this is the URL that is needed to be accessed. This URL tell about

the last reading and the last time when the data was recorded. Below mentioned image

is the glimpse of the server page.

Fig | The web application

http://scl.fabroll.com/


Chapter 7

References

1. Atmega 16 data sheet.

2. USB to serial data sheet.

3. Energy meter manuals

4. Serial communication manuals of AVR

5. GSM Modem manual

6. AT commands manual


Appendix 1

The codding

/*

* Source code.c

*

* Created: 19/Mar/2014 15:48:10

* Author: acer

*/

#include <avr/io.h>


#include <util/delay.h>

#include "lcd.h"

uint16_t E_data;

char digits[2];

/*Macros definition*/

#define BIT(x) (1 << (x)) //Set a particular bit mask

#define CHECKBIT(x,b) x&b //Checks bit status

#define SETBIT(x,b) x|=b; //Sets the particular bit

#define CLEARBIT(x,b) x&=~b; //Sets the particular bit

#define TOGGLEBIT(x,b) x^=b; //Toggles the particular bit

void EEPROM_write(unsigned int uiAddress, unsigned char ucData);

unsigned char EEPROM_read(unsigned int uiAddress);

save_EEPROM(unsigned int add,unsigned int data);

read_EEPROM(unsigned int add);

void USART_SEND_INT(int data);

void USART_SEND_DEC(int num);

void USARTInit(uint16_t ubrr_value)


{

UBRRL = ubrr_value;

UBRRH = (ubrr_value>>8);

UCSRC=(1<<URSEL)|(3<<UCSZ0);

UCSRB=(1<<RXEN)|(1<<TXEN);

}

char USARTReadChar()//For reading a single character

{

while(!(UCSRA & (1<<RXC)))

{

//Do nothing

}

return UDR;


}

void USARTWriteChar(char data)//For writing a single character

{

while(!(UCSRA & (1<<UDRE)))

{

//Do nothing

}

UDR=data;

}

void USARTWriteString(char* StringPtr)//For writing a string

{

while(*StringPtr != 0x00)

{ //Here we check if there is still more chars to send, this is done

checking the actual char and see if it is different from the null char

USARTWriteChar(*StringPtr); //Using the simple send function we send

one char at a time

StringPtr++;

} //We increment the pointer so we can read the next char


}

void SIM900Init(void)

{

char command[60];

char ret;

sprintf(command, "AT+SAPBR=3,1,\"APN\",\"airtelgprs.com\"");

USARTWriteString(command);

USARTWriteChar(13);

USARTWriteChar(10);

LCDWriteStringXY (0,0, "Setting up GPRS.");

_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{

ret = USARTReadChar();

if (ret == 13)

{

//i--;

}

else if (ret ==10)


{

//i--;

}

else

{

LCDGotoXY(i,0);

LCDData(ret);

}

}

_delay_ms(1000);

sprintf(command, "AT+SAPBR=1,1");


USARTWriteChar(13);

USARTWriteChar(10);

LCDClear();

LCDWriteStringXY(0,0, "Setting APN");

_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)


{

//i--;

}

else if (ret ==10)

{

//i--;

}

else

{

LCDGotoXY(i,0);

LCDData(ret);

}

}

_delay_ms(1000);

sprintf(command, "AT+CREG?");


USARTWriteChar(13);

USARTWriteChar(10);

LCDClear();

LCDWriteStringXY(0,0, "Checking registration status");

_delay_ms(1000);


LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)

{

//i--;

}

else if (ret ==10)

{

//i--;

}

else

{

LCDGotoXY(i,0);

LCDData(ret);

}

}

_delay_ms(1000);

sprintf(command, "AT+SAPBR=2,1");



USARTWriteChar(13);

USARTWriteChar(10);

LCDClear();

LCDWriteStringXY(0,0,"Querying bearer 1");

_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)

{

//i--;

}

else if (ret ==10)

{

//i--;

}

else

{

LCDGotoXY(i,0);

LCDData(ret);


}

}

_delay_ms(1000);

sprintf(command, "AT+HTTPINIT");


USARTWriteChar(13);

USARTWriteChar(10);

LCDClear();

LCDWriteStringXY(0,0,"Intializing HHTP");

_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)

{

//i--;

}

else if (ret ==10)

{

//i--;

}


else

{

LCDGotoXY(i,0);

LCDData(ret);

}

}

_delay_ms(1000);

}

void http_send(int main_, int dec_)

{

LCDClear();

char ret;

char command[100];

sprintf(command,

"AT+HTTPPARA=\"URL\",\"http://efyjaipur.com/shree_cement/load_pecrc.php?main=

%d&dec=%d\"", main_, dec_);


USARTWriteChar(13);

USARTWriteChar(10);

LCDWriteStringXY(0,0, "Sending data to URL");

LCDWriteStringXY(0,1, "Reading");

LCDWriteStringXY(11,1, ".");

LCDWriteIntXY(8,1, main_,3);

LCDWriteIntXY(12,1, dec_,2);

_delay_ms(1000);

for(int i = 0; i<2; i++)


{


if (ret == 13)

{

//i--;

}

else if (ret ==10)

{

//i--;

}

else

{

//LCDGotoXY(i,0);

//LCDData(ret);

}

}

_delay_ms(1000);

LCDClear();

sprintf(command, "AT+HTTPPARA=\"CID\",1");


USARTWriteChar(13);


USARTWriteChar(10);

LCDWriteStringXY(0,0, "Sending HTTP Parameters");





_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)

{

//i--;

}

else if (ret ==10)

{

//i--;

}

else

{

LCDGotoXY(i,0);


LCDData(ret);

}

}

sprintf(command, "AT+HTTPACTION=0");


USARTWriteChar(13);

USARTWriteChar(10);

LCDWriteStringXY(0,0, "Sending HTTP Action");





_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)

{

//i--;

}

else if (ret ==10)

{

//i--;


}

else

{

LCDGotoXY(i,0);

LCDData(ret);

}

}

sprintf(command, "AT+HTTPREAD");


USARTWriteChar(13);

USARTWriteChar(10);

LCDWriteStringXY(0,0, "Reading HTTP");





_delay_ms(1000);

LCDClear();

for(int i = 0; i<2; i++)

{


if (ret == 13)

{

//i--;


}

else if (ret ==10)

{

//i--;

}

else

{

LCDGotoXY(i,0);

LCDData(ret);

}

}

}

int main(void)

{

int unit_main;

char unit_decimal;

char check=0;

InitLCD(LS_BLINK);


USARTInit(103);

SIM900Init();

LCDClear();

LCDWriteStringXY(0,0," ONLINE E Meter ");

LCDWriteStringXY(0,1," MONITORING ");

_delay_ms(1000);

SETBIT(DDRC,BIT(5));

CLEARBIT(DDRC,BIT(4));

SETBIT(PORTC,BIT(4));

LCDClear();

/**********************************/

//First Time Initialisation to erase memory block//

//keep the fuse EF C1 to avoid erasing memory block//

//save_EEPROM(20,0);

//EEPROM_write(30,0);

//EEPROM_write(40,0);

/*********************************/

int i = EEPROM_read(40);

unit_decimal = EEPROM_read(30);

unit_main = read_EEPROM(20);

LCDWriteStringXY(4,1,".");


while(1)

{

//TODO:: Please write your application code

if( (PINC&(1<<4)) == 0 )

{

//LCDWriteStringXY(0,1,"if loop");

SETBIT(PORTC,BIT(5));

_delay_ms(200);

CLEARBIT(PORTC,BIT(5));

i++;

LCDWriteIntXY(0,0,i,3);

EEPROM_write(40,i);

check=1;

}

if(i==32)

{

i=0;

unit_decimal ++;

EEPROM_write(30,unit_decimal);

}

if (unit_decimal == 100)

{


unit_decimal = 0;

unit_main ++;

save_EEPROM(20,unit_main);

}

//LCDWriteIntXY(0,1,unit_main,4);

//LCDWriteIntXY(5,1,unit_decimal,2);

http_send(unit_main, unit_decimal);

_delay_ms(10000);

// else

// {

// LCDWriteStringXY(0,1,"else loop");

// }

}

}


save_EEPROM(unsigned int add,unsigned int data)

{

uint16_t data_l,data_h,data_f;

data_f = data;

data_l = data_f & 0x00FF;

data_h = data_f >> 8;

EEPROM_write(add,data_h);

add++;

EEPROM_write(add,data_l);

}

read_EEPROM(unsigned int add)

{

//use E_data to store the full value

uint16_t data_l,data_h;

data_h = EEPROM_read(add);

add++;


data_l = EEPROM_read(add);

E_data = ((data_h<<8)|data_l);

return E_data;

}

void EEPROM_write(unsigned int uiAddress, unsigned char ucData)

{

// sei();

/* Wait for completion of previous write */

while(EECR & (1<<EEWE))

;

/* Set up address and data registers */

EEAR = uiAddress;

EEDR = ucData;

/* Write logical one to EEMWE */

EECR |= (1<<EEMWE);

/* Start eeprom write by setting EEWE */

EECR |= (1<<EEWE);

// sei();

}


unsigned char EEPROM_read(unsigned int uiAddress)

{

//CLEARBIT(SREG,BIT(7));

/* Wait for completion of previous write */

while(EECR & (1<<EEWE))

;

/* Set up address register */

EEAR = uiAddress;

/* Start eeprom read by writing EERE */

EECR |= (1<<EERE);

/* Return data from data register */

return EEDR;

//SETBIT(SREG,BIT(7));

}

a project report on energy meter monitoring online using wireless transmission gsm modem

Documents

etsi gsm standard

gsm mou

gsm evolution

gsm association

european standard

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gsm global system

global standard