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AUTOMATIC STREET LIGHT CONTROL USING LDR
This project aims at designing and executing the advanced development in embedded systems for energy saving of street lights with light depending resistor. Nowadays, human has become too busy and he is unable to find time even to switch the lights wherever not necessary. This can be seen more effectively in the case of street lights. The present system is like, the street lights will be switched on in the evening before the sun sets and they are switched off the next day morning after there is sufficient light on the roads. But the actual timings for these street lights to be switched on are when there is absolute darkness. With this, the power will be wasted up to some extent. This project gives the best solution for electrical power wastage. Also the manual operation of the lighting system is completely eliminated.
In our project we are using LDR, which varies according to the amount of light falling on its surface, this give an indication for us whether it is a day/night time. We have placed IR sensors in both sides of the road, which can be controlled by Micro controller (AT89C51).The IR‘s will be activated only on the night time. If any obstacle crosses the IR, automatically particular light will be ON, for few seconds.
In our project we use regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/12V step down transformer.
The programming language used for developing the software to the microcontroller is Embedded/Assembly. The KEIL cross compiler is used to edit, compile and debug this program. Here in our application we are using AT89C51 microcontroller which is Flash Programmable IC.AT represents the Atmel Corporation ‘C’ represents CMOS technology is used for designing the IC. We believe that our idea provides better than the existing system.
In the present project street lights are taken into consideration where the above discussed factors are rectified in them. This is achieved with the help of an embedded system. By using this as the basic principle we can design centralized intelligent system for the perfect usage of streetlights in any place (Viz Village, Town) can be developed.
Embedded systems are designed to do some specific task, rather than be a general-purpose computer for multiple tasks. Some also have real time performance constraints that must be met, for reason such as safety and usability; others may have low or no performance requirements, allowing the system hardware to be simplified to reduce costs.
An embedded system is not always a separate block - very often it is physically built-in to the device it is controlling. The software written for embedded systems is often called firmware, and is stored in read-only memory or flash convector chips rather than a disk drive. It often runs with limited computer hardware resources: small or no keyboard, screen, and little memory.
Wireless communication has become an important feature for commercial products and a popular research topic within the last ten years. There are now more mobile phone subscriptions than wired-line subscriptions. Lately, one area of commercial interest has been low-cost, low-power, and short-distance wireless communication used for \personal wireless networks." Technology advancements are providing smaller and more cost effective devices for integrating computational processing, wireless communication, and a host of other functionalities. These embedded communications devices will be integrated into applications ranging from homeland security to industry automation and monitoring. They will also enable custom tailored engineering solutions, creating a revolutionary way of disseminating and processing information. With new technologies and devices come new business activities, and the need for employees in these technological areas. Engineers who have knowledge of embedded systems and wireless communications will be in high demand. Unfortunately, there are few adorable environments available for development and classroom use, so students often do not learn about these technologies during hands-on lab exercises. The communication mediums were twisted pair, optical fiber, infrared, and generally wireless radio.
Objective of the project:-
The main consideration in the present field technologies are Automation, Power consumption and cost effectiveness. Automation is intended to reduce man power with the help of intelligent systems. Power saving is the main consideration forever as the source of the power(Thermal, Hydro etc.,)are getting diminished due to various reasons.
The main aim of the project is Automatic street power saving system with LDR, this is to save the power. We want to save power automatically instead of doing manual. So its easy to make cost effectiveness. This saved power can be used in some other cases. So in villages, towns etc we can design intelligent systems for the usage of street lights.
Block Diagram Explanation: .
In this project, we are going to switch off the street lights automatically as the day starts. The duration of the day differs from season to season, accordingly our module works based upon the light intensity so as to when to start or stop. For this we are using Light Dependent Resistor (LDR) as the light sensor, which communicates with the required information to the micro controller.
Here we are using micro controller, LDR, and relay. By using the LDR we can operate the lights, i.e when the light is available then it will be in the OFF state and when it is dark then the light will be in ON state, it means LDR is inversely proportional to light. When the light falls on the LDR it sends the commands to the micro controller that it should be in the OFF state then it switch off’s the light, all these commands are sent to the controller then according to that the devices operate. We use a relay to act as an ON OFF switch, the load is connected to these relays.
The block diagram of the system is as shown in the fig. The system basically consists of a
1. Micro controller,
4. Power supply,
Microprocessor has following instructions to perform:
1. Reading instructions or data from program memory ROM.
2. Interpreting the instruction and executing it.
3. Microprocessor Program is a collection of instructions stored in a
4. Read Data from I/O device
5. Process the input read, as per the instructions read in program memory.
6. Read or write data to Data memory.
7. Write data to I/O device and output the result of processing to O/P device.
NECESSITY OF MICROCONTROLLERS:
Microprocessors brought the concept of programmable devices and made many applications of intelligent equipment. Most applications, which do not need large amount of data and program memory, tended to be:
The microprocessor system had to satisfy the data and program requirements so, sufficient RAM and ROM are used to satisfy most applications .The peripheral control equipment also had to be satisfied. Therefore, almost all-peripheral chips were used in the design. Because of these additional peripherals cost will be comparatively high.
8085 chip needs:
An Address latch for separating address from multiplex address and data.32-KB RAM and 32-KB ROM to be able to satisfy most applications. As also Timer / Counter, Parallel programmable port, Serial port, Interrupt controller are needed for its efficient applications.
In comparison a typical Micro controller 8051 chip has all that the 8051 board has except a reduced memory as follows.
4K bytes of ROM as compared to 32-KB, 128 Bytes of RAM as compared to 32-KB. Bulky:
On comparing a board full of chips (Microprocessors) with one chip with all components in it (Micro controller).
Lots of Microprocessor circuitry and program to debug. In Micro controller there is no Microprocessor circuitry to debug.
Slower Development time: As we have observed Microprocessors need a lot of debugging at board level and at program level, where as, Micro controller do not have the excessive circuitry and the built-in peripheral chips are easier to program for operation.
So peripheral devices like Timer/Counter, Parallel programmable port, Serial Communication Port, Interrupt controller and so on, which were most often used were integrated with the Microprocessor to present the Micro controller .RAM and ROM also were integrated in the same chip. The ROM size was anything from 256 bytes to 32Kb or more. RAM was optimized to minimum of 64 bytes to 256 bytes or more.