Energy Meter Reading Using Bluetooth Technology

This project is designed with microcontroller, Bluetooth transmitter & Receiver, and data cable with PC.

Bluetooth is an industrial specification for wireless personal area networks (PANs).Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally unlicensed short-range radio frequency.

In microcontroller we can program the cost per unit. So it receives the pulse from signal conditioning unit and increments the count value. Corresponding unit and cost are displayed on the LCD display.

In this project the energy meter will send the meter reading to the Bluetooth device via the microcontroller. The Bluetooth thus transmits the data and sends it to the receiving side which will be indicated on the computer screen. The reading can be sent back after sufficient calculation to the energy meter display via Bluetooth devices.

Introduction:

A huge manpower is arranged by electric power company to collect the electricity meter reading. It is a costly job and easily getting wrong readings. In some cases, the staff of electric power company is not able to enter the private house and hence needed to estimate the power usage.

An innovative solution is created to simplify the job by using Bluetooth technology. Meter reading can be taken easily and efficiently by using a Bluetooth device connected to the electric power meters with Bluetooth module installed. By using this solution, it eliminates the human error and does not need to estimate the electricity usage anymore. As a result, electric power company can reduce the operation time dramatically.

This project basically aims to provide a new wireless design for Energy Meter Reading using Bluetooth Technology.

Traditional system:

During a research at the Tamil Nadu Electricity Board, a questionnaire was conducted about the traditional methods of Assessment of Meter Reading followed in Tamil Nadu and was found that few years ago there were readings taken manually and costs generated by manual calculation which has now been replaced by the project called BEST (Billing for Essential Services in TNEB) scheme which has two phases of implementation. With this project TNEB plans to computerize all their collection centers spread across Tamil Nadu. A handheld device is used by the assessor to generate the bill of the consumer based on the observed reading. The remote rural office of TNEB is being connected to a circle office and the circle office is being connected to the Regional office.

Gemini Communication Ltd (GCL), a Chennai based leader in Communication & Networking solutions did the first phase for about 456 Collection centers spread across 9 regions and deployed the servers and storage products for this network and hence the data that is being typed in at the remote rural office will automatically be saved in the server of the Regional office.

In the second phase TNEB would implement the system in 8 regions catering to 1725 collection centers. This is the second phase of the project and will be used by 8 Chief Engineers and expected to benefit over 1.5 crore consumers.

Proposed system:

However in the existing system there is no solution provided for the misread meters and manual errors by the assessors. Also it does not provide a solution to reduce the manpower required as assessors.

The proposed method is that of a wireless meter reading system. A mobile van or motorbike can be used by the staff to visit a street and it is required to enter only the building code to access all the meter readings of the building. The proposed design involves a microcontroller block that read up to 16 energy meters per building. Then the bill of the individual meter will be generated and displayed on the LCD screen of the microcontroller at the consumer end.

This system will provide the readings of each and every meter in a building even if the staff is unable to enter the building. There are further uses of this system which are mentioned in the advantages section.

Originality/value:

This system has many significant excellences, such as wireless networking, low-workload, great quantity of data transmission, time- saving, security. It is an integrated system with complete hardware, software, and database implementation.

Block diagram:

Devices used and working:

1. Electricity meter

The first block is an electric meter that is to be read. An Electric meter or energy meter is a device that measures the amount of electrical energy supplied to a residence or business. These are customers of an electric company.

The most common type is more properly known as a (kilo) watt-hour meter or a joule meter. Utilities record the values measured by these meters to generate an invoice for the electricity. They may also record other variables including the time when the electricity was used.

Fig.1: Energy Meter

Typical Energy meter data

5-10 v

240 v

50 Hz

1200 revs/kwh

2. IR Transmitter and receiver

For the microcontroller to understand the meter reading, we need an IR setup which consists of an IR transmitter and receiver. The transmitter transmits an IR ray via a hole made in the meter disc, and the receiver receives it whenever the hole comes right in straight line with the IR ray. This happens on completion of each revolution of the disc. So this ensures that the microcontroller has track of each revolution and the counter works accordingly.

A typical Infrared diode emits a beam of light that reaches the device. A 940 nm wavelength LED is typical. This infrared light is invisible to the human eye but carries signals that are detected by the appliance, as well as by the sensor of a digital camera. The presence of a carrier signal can be used to trigger a function. After the demodulation of the received signal, the appropriate frequency filters are applied to separate the respective signals. Nowadays digital procedures are more commonly used.

Fig.2: IR transmitter and receiver

3. Digital comparator

The comparator shown in the block diagram is used to sense a high pulse each time the IR receiver receives an IR light. And the comparator compares the coming signal to previous signal. If they are different the output is given as high and if they are same the output is zero. This ensures that when the meter stops on one reading the microcontroller stops counting. A digital comparator is a hardware electronic device that compares two numbers in binary form and generates a one or a zero at its output depending on whether they are the same or not.

A comparator can be simulated by subtracting the two values (A & B) in question and checking if the result is zero. This works because if A = B then A – B = 0.

Comparator Operation

Input Vs. Output Results

Current WILL flow through the open collector when the voltage at the PLUS input is lower than the voltage at the MINUS input of the opamp.

Current WILL NOT flow through the open collector when the voltage at the PLUS input is higher than the voltage at the MINUS input of the opamp.

4. 8051 Microcontroller

The microcontroller is used to count the pulses coming from the comparator output and to interface it to the Bluetooth device for Transmission and reception. It also interfaces to the LCD display so that the incoming Bill details can be displayed. The microcontroller consists of following sections:

4 Kb program memory.

128Kb RAM (including SFR(special function registers) as well) satisfies basic needs.

4 ports having in total of 32 input/output lines exist.

Fig.3: 8051 Pinout and Basic Architecture

The diagram above shows the 8051 pinout. The chip is a 40-pin package.

Port 0 – pins 32 to 39 make up the 8-bit I/O port 0. However, if external memory is used, these lines are used as a multiplexed address and data bus.

Port 1 – pins 1 to 8 make up the 8-bit I/O port 1.

Port 2 – pins 21 to 28 make up the 8-bit I/O port 2. However, if external memory is used, these lines make up the high-byte of the external address (A8 to A15).

Port 3 – pins 10 to 17 make up the 8-bit I/O port 3. However, each of these eight pins also has an alternate function, as detailed in the table below:

External data memory read strobe

RST – the reset input is on pin 9. This pin is used for resetting the 8051 (i.e.; loading the PC with the correct startup value).

EA-bar – the external access, on pin 31, is used for enabling or disabling the on-chip ROM. When tied high (5V), the 8051 executes instructions in internal ROM when executing in the lower 4K (8K for the 8052) of memory. If tied low the 8051 will always execute instructions in external memory. The 8031 and 8032 should always have pin 31 tied low as there is no internal code memory.

ALE – the address latch enable is on pin 30. The ALE is used for latching

the low byte of the address into an external register.

PSEN-bar – the program store enable is an output signal on pin 29. This signal is used for fetching instructions from external code memory.

The microcontroller memory is divided into Program Memory and Data Memory. Program Memory (ROM) is used for permanent saving program being executed, while Data Memory (RAM) is used for temporarily storing and keeping intermediate results and variables. All 8051 microcontrollers have 16-bit addressing bus and can address 64 kb memory.

5. Bluetooth

The Bluetooth device is used create the contact between the Consumer’s meter and the Assessor’s laptop or any Bluetooth enabled device which has the Billing Software in it.

Bluetooth is the term used to describe the protocol of a short range (10 meter) frequency-hopping radio link between devices. Bluetooth is acceptable for situations when two or more devices are in proximity to each other and don’t require high bandwidth. Bluetooth networking transmits data via low-power radio waves at frequency of 2.45 gigahertz (actually between 2.402 GHz and 2.480 GHz, to be exact). This frequency band has been set aside by international agreement for the use of industrial, scientific and medical devices (ISM). A personal computer must have a Bluetooth adapter in order to be able to communicate with other Bluetooth devices (such as mobile phones, mice and keyboards).

6. Visual Basic

The software used to enter the received readings and generate the billing cost details is Visual Basic as the front-end software and SQL as the back-end software where the database of each consumer gets stored.

Visual Basic is a Graphics User Interface (GUI). The main object in

Visual Basic is called a form. Controls are things like text boxes, check boxes and command buttons. Controls are chosen from the Visual Basic “tool box”. Once forms/controls are created, you can change the properties (appearance, structure etc.) related to those objects in that particular objects properties window. From this window, you choose the property you want to change from the list and change its corresponding setting. Once all your objects are created, you can combine them to form a single executable program that can be run outside of the Visual Basic environment, in Microsoft Windows as shown:

Advantages:

Issues with Stand-alone meter reading

Highly Person dependant.

Human errors cannot be avoided.

Accessibility of meters in rural/ Agricultural zones.

Energy Audits performed based on bill collection which is highly inaccurate.

Billing done mainly on estimated/ monthly average basis

Inability to monitor and control discrete loads

Billing cycle requires excessive time.

Electric company benefits

Smart automated processes instead of manual work

Accurate information from the network load to optimise maintenance and investments

Customized rates and billing dates.

Streamlined high bill investigations.

Better network performance and cost efficiency.

Demand and distribution management.

More intelligence to business planning.

Better company credibility.

Customer benefits

Precise consumption information

Clear and accurate billing

Better and faster customer service

Disadvantages:

Applying the system in large area with multiple subscribers is not a straightforward task; the system may need some modifications.

Bluetooth device costs are affordable only by Apartment residents or residents of colonies but not independents.

Future developments:

In our project we have used the old fashion mechanically operating meters but they are easy to tamper with. In future digital meters can be used for this project once they become cheaper.

The other proposed advancement that can be made is the use of other wireless communication devices. Bluetooth model was used by us essentially for lab testing purposes. The more favourable options could be Modems and Zigbee devices that provide both range and better security. They were not chosen for this project due to budget restrictions.