VLC was first envisaged as a method of data transmission that operates on a point-to-point basis, effectively functioning as a substitute for cables. In Figure 2, the result of this is that early VLC standardisation operations have been carried out as part of IEEE 802.15.7 [3]. On the other hand, this standard is now undergoing revisions in order to include Li-Fi. On the other hand, Li-Fi refers to an all-encompassing cellular wireless networking system. Additionally, this encompasses communication between several users in both directions, also known as point-to-multipoint and multipoint-to-point communication. The formation of a wireless network consisting of extremely tiny optical attocells is another component of Li-Fi, which also comprises many access points and smooth handover. Consequently, this indicates that Li-Fi makes it possible for users to move about freely, and as a result, it creates a new layer inside the current heterogeneous wireless networks.
Design Architecture
In the Figure 3, the fact that LEDs are natural beamformers makes it possible to localise the confinement of Li-Fi signals. Additionally, since opaque walls block the signals, it is possible to efficiently regulate co-channel interference and to improve the security of the physical layer. The most important methods that are required to establish optical attocell Li-Fi networks are shown in Figure 2, which can be found in [4].
LI-FI TRANSMITTER:
A way of transmitting data that makes use of lightning is known as Li-Fi. In other words, it sends information via the light that is produced by the LED. The brightness of this light bulb fluctuates at a rate that is too rapid for the human eye to keep up with. Data transfer done using a single or more LEDs that are functional[11]. In figure 4, a Li-Fi transmitter typically consists of an LED light bulb or another light-emitting device that modulates the light intensity at a very high speed, which is then received by a Li-Fi receiver, often integrated into a device like a smartphone or a computer.
Here's a basic overview of how a Li-Fi transmitter works:
LED Light Source: The transmitter typically uses LED light bulbs as the light source. LED bulbs are preferred because they can be modulated rapidly without any perceivable flickering.
Modulation: The intensity of the light emitted by the LED is modulated very rapidly to encode data. This modulation is often done using techniques like Pulse Width Modulation (PWM) or Orthogonal Frequency Division Multiplexing (OFDM)[17].
Data Encoding: Digital data is converted into a stream of light pulses. These pulses are transmitted by the LED in such a way that they can be received and decoded by a Li-Fi receiver.
Transmission Range: The range of Li-Fi transmission depends on factors such as the power of the LED, the sensitivity of the receiver, and any obstacles in the transmission path. Li-Fi generally operates within a shorter range compared to Wi-Fi, but it can achieve very high data transfer rates over short distances.
Security: One of the potential advantages of Li-Fi is its inherent security. Since light cannot penetrate through walls like radio waves, Li-Fi signals are confined to the space illuminated by the light source, making it more difficult for unauthorized users to intercept the signal.
TX:
LDR SENSOR:
When referring to a device, the phrase "light dependent resistor" is used to describe one in which the resistance of the device is determined by the electromagnetic radiation that the device is exposed to. One of the events that takes place is referred to as photoconductivity, and it occurs when a material absorbs radiation. The process by which the material becomes more conductive is referred to as this phenomena to characterise the process. electrons that are in the valence band of the semiconductor material are stimulated into the conduction band when light enters the device and photons strike it. This occurs when the device is exposed to light.
MQ3 SENSOR:
The MQ3 sensor is the one that is used the most often when it comes to the series of sensors it belongs to. Metal oxide is the main component in the production of this semiconductor. Chemiresistors are another name that is sometimes used to refer to metal oxide sensors. Because they rely their functioning on the change in resistance of the sensor material when it is exposed to alcohol, this is the reason why they are able to maintain their functionality.
VIBRATION SENSOR:
With the assistance of these multipurpose sensors, it is possible to assess the efficiency of a huge number of different operations. This sensor alters the electrical charge in order to accumulate the information necessary for monitoring changes in acceleration, pressure, temperature, force, or strain. It does this in order to collect the information.
ULTRA SONIC SENSOR:
Ultrasonic sensors are able to search for reflected waves that are emitted by objects by using ultrasonic pulses that are transmitted into the air. Automotive reversing sensors, automatic door openers, and criminal alarm systems are just some of the electronic devices that make use of ultrasonic sensors. Ultrasonic sensors are also employed in a broad range of other electronic devices.
RX:
LCD:
LCD is an abbreviation that stands for liquid crystal display. In the Figure 5, this technology is used in scratch pad displays as well as various little personal computers. Compared to the breakthroughs that were made possible by Cathode Ray Tube (CRT) technology, liquid crystal displays (LCDs), which are comparable to Light Emitting Diode (LED) and Gas Plasma technologies, provide presentations that are more compact. In comparison to gas displays and LED displays, LCD panels use a fraction of the amount of energy that others do.
BUZZER:
As an example of an inaudible signalling device, a buzzer functions. Buzzers and beeps are often used for a variety of functions, including but not limited to educating, alerting, timers, and the confirmation of user input, which includes mouse clicks and keystrokes.
LIFI-RECEIVER:
A solar panel that receives light and data is part of the new LIFI receiver. There is a 9600 baud rate. Without any obstructions, move up to 15 feet. Reception range is affected by moderate sunshine. To extend the range, you can change the trimpot on the receiver board.
In the Figure 6, A Li-Fi receiver is the counterpart to the Li-Fi transmitter in a Li-Fi communication system. It's responsible for receiving the modulated light signals transmitted by the Li-Fi transmitter and converting them back into digital data that can be understood by electronic devices like computers, smartphones, or other data-processing systems. Here's how a Li-Fi receiver typically works:
Photodetector: At the heart of a Li-Fi receiver is a photodetector, such as a photodiode or a photodiode array. This component detects the variations in light intensity caused by the modulated light signal and converts them into electrical signals.
Signal Processing: The electrical signals generated by the photodetector are then processed by the receiver's circuitry. This processing involves filtering out noise, amplifying the signal, and extracting the modulated data.
Demodulation: The receiver uses demodulation techniques to extract the original digital data from the modulated light signal. This process typically involves reversing the modulation scheme used by the transmitter, such as Pulse Width Modulation (PWM) or Orthogonal Frequency Division Multiplexing (OFDM).
Error Correction: In some cases, the receiver may employ error correction techniques to mitigate any errors introduced during transmission. This can improve the reliability and accuracy of the received data.
Data Output: Once the digital data has been successfully recovered, it is outputted by the receiver to the connected device or system, such as a computer or smartphone, for further processing and utilization.
Range and Performance: The performance and range of a Li-Fi receiver depend on factors such as the sensitivity of the photodetector, the quality of the signal processing algorithms, and the characteristics of the transmitted light signal. Receivers are designed to operate efficiently within the specified range of the Li-Fi system and to handle the data rates supported by the transmitter.
BLOCK DIAGRAM:
Examples of low-power CMOS 8-bit microcontrollers include the ATmega48PA, 88PA, 168PA, and 328P. These microcontrollers have an architecture that is based on the AVR enhanced RISC standard. It is possible for the ATmega48PA/88PA/168PA/328P to achieve throughputs that are very near to 1 MIPS per MHz. This is made possible by the fact that they are able to conduct strong instructions inside a single clock cycle. Because of this, apps are able to tailor their power consumption and processing performance without compromising their efficiency. There are a total of 32 general purpose working registers and an instruction set that are included into the setup of the AVR core. As a result of the fact that the Arithmetic Logic Unit (ALU) is directly connected to each of the 32 registers, it is feasible to access two different registers with a single instruction during the span of a single clock cycle.The architecture that was designed as a result of this resulted in an improvement in the efficiency of the code while simultaneously achieving a throughput that is up to 10 times quicker than that of typical CISC microcontrollers. During the manufacturing process of the device, a high density non-volatile memory technology that was invented by Atmel is used. It is possible to update the system's programme memory using on-chip ISP Flash by using a serial SPI interface, a conventional non-volatile memory programmer, or an on-chip boot programme that is based on an AVR core. All of these methods are available inside the system. When the application is used, the boot programme has the capability of downloading the application programme into the application flash memory via any interface. This is feasible because the application is used. It is possible to do genuine simultaneous read and write operations because the software in the boot flash region continues to run even while the application flash area is being updated. This makes it possible to perform both actions simultaneously. High-performance microcontrollers for embedded control applications, such as the Atmel ATmega48PA/88PA/168PA/328P, combine an 8-bit RISC central processing unit (CPU) with an essentially self-programmable memory on a monolithic chip. These microcontrollers are designed to handle a wide range of embedded control applications. The combination of these two factors makes these microcontrollers unique in terms of their versatility and their economical value. In order to facilitate the development of systems and programmes for the ATmega48PA/88PA/168PA/328P AVR, a complete set of tools is offered. Evaluation Kits, Computer Compilers, Macro Assemblers, Software Debuggers and Simulators, and In-Circuit Emulators are some of the instruments that fall under this category.
There is also the possibility of the signal being passed from the front vehicle to the front vehicle in order to reach the traffic signal post receiver. This enables direct connection between the emergency vehicles and the traffic signal. When it comes to communicating, there is yet another approach that may be used. There is still another kind of communication that is being used here. Consequently, the amount of money that is necessary to finish the Li-Fi module repair away from the road is reduced as a result of this. The information that is shown below will be displayed on the display of the automobile in the event that it receives a signal from another vehicle that is reacting to an emergency situation. In addition to this, it will send a message to the vehicle that is next to it, notifying it that "an emergency vehicle is on your lane and should move forward." This will take place while the previous statement is being made. This specific car, which is now positioned in the first row, is the one that is responsible for transferring the signal to the traffic post in order to cause the light to change to green for that particular lane alone. The stop status has been sent to the car signals for the lanes that are still available that are still available.
ARDUINO IDE:
The Integrated Development Environment, sometimes referred to as Arduino IDE, is a piece of software that was developed by Arduino.cc and made accessible to the general public. Its major objective is to make the process of creating code, compiling that code, and uploading it to Arduino devices easier. Without encountering any difficulties, each and every Arduino module may be used using the code. The fact that the application is open source and relatively easy to use makes it possible for you to easily download and build code while you are travelling.
Introduction to Arduino IDE:
The Arduino Integrated Development Environment (IDE), which is open-source software, is used for the purpose of creating code and compiling it into Arduino Modules throughout the majority of situations. Due to the fact that it is an official compilation of Arduino software code, it is so simple to comprehend that even the average person who has no prior knowledge with technology may start learning about computer technology. The environment in which it functions is supported by the Java Platform, which is widely accessible for use on a variety of operating systems, including MAC, Windows, and Linux for example. In order to facilitate the process of debugging, modifying, and compiling the code that is present in the environment, this platform is outfitted with all of the essential functions and instructions that are built in. There is a wide selection of Arduino modules that may be purchased, including the Uno, Mega, Leonardo, and Micro, in addition to a large lot of other possibilities. Every single one of them is equipped with a microcontroller that is really programmed and is able to take in data in the context of code. Every single one of them has this microcontroller embedded in the board that they use. When the primary code, which is also known as a sketch, is created on the platform of the integrated development environment (IDE), it will finally result in the production of a Hex File. Afterwards, this Hex File is sent to the controller that is located on the board, and it is then uploaded into it.
In the Figure 7&8, the Editor and the Compiler are the two fundamental components that make up the interface development environment, sometimes known as the IDE. In the course of the process of creating the necessary code, the Editor is utilised, and the Compiler is utilised in order to compile the code and upload it into the Arduino Module that has been selected. This integrated development environment (IDE) is capable of supporting applications written in both C and C++.
Project Hard Ware and Software Setup:
Take, for example, the case when the vehicle travelling in the other way has headlights that are fairly bright. The light will then be recognised by this sensor, which will subsequently convey the information to the automobile on the other side by reducing the intensity of the light. As shown in figure 9&10, a confirmation of the distance between the two vehicles will be provided by this sensor, which will first calculate the distance between the two automobiles and then communicate that information to the vehicle that is directly opposite it.
When the Driver Will blow off the air. then the Sensor will detect His condition and the information is passed Through the Li-Fi Transmitter to other Vehicle Receiver.
When the vehicle occurred Accident then this sensor will detect it and send information to the Another vehicle
DATA STORED IN CLOUD:
The technique that has been suggested is validated by using a tool that replicates Arduino platforms in order to verify its effectiveness. During the production process, photo diodes and LED lights are used to efficiently produce the Li-Fi modules. This allows for the modules to be manufactured. Within the scope of the arrangement, there were two different quantities of Arduino boards that were put into place. The first one is a Li-Fi module for emergency vehicles, while the second one is either a module for surrounding automobiles or a traffic signal module. Both of these modules are used to enable communication between vehicles. Both of these modules may be switched out for one another. In the same manner as the photo diodes on the modules are performing the function of a receiver, the LED lights are performing the function of a transmitter from the modules. This is occurring concurrently between the two functions that are being performed. Through the use of pulse width modulation (PWM), it is feasible for the LED light that is attached to the emergency vehicle to transmit a particular message to the vehicle that is in close proximity to it. The 16x2 LCD display that is permanently attached on top of the Li-Fi module that is situated on the receiving side displays the messages that have been received. This display is installed on the receiving side. The LED lights that are connected to the breadboard in a number of different ways come together to form a traffic signal configuration. The message that is received is what determines the function of the establishment that is used for the traffic signal. An activation of the signal occurs as a direct result of this particular circumstance. The Arduino board incorporates modifications to pulse width modulation (PWM) by means of an inbuilt slot. These modifications are included into the board. By using this slot, it is possible to determine the frequency at which the LED operates and make adjustments accordingly.
This data is transferred through wifi module to the server. Then the server stores all sensors information.
For the purpose of showing the message that was received from the transmitter module, an LCD display on the Arduino board has been permanently attached. For the purpose of receiving the signals that are sent by the transmitter module, the receiver Arduino is equipped with a Li-Fi module. The findings are shown on the display on the side of the car as well as on the traffic signal light. The number of times the light blinks on the transmitter module is determined by the frequency of the light. As shown in above figures11,12,13,14 & 15 In order to guarantee that the display displays a variety of messages, the receiver module located in each lane is created. Based on the picture that was generated, it seems like there is a car that is positioned in the same lane as an emergency vehicle. in order to ensure that the LED for the traffic light and the messages that said "Go Forward" were shown simultaneously. In a similar fashion, the LCD display in the front row also displays information about the position of the emergency vehicle on the road. The section of the Li-Fi module that may send signals. Only in the event that a vehicle is getting closer to the emergency vehicle does the gearbox portion go to the "ON" position. Additionally, an ultrasonic sensor is attached to the transmitter side of the Arduino board in order to facilitate this application. A signal is sent to the microcontroller via the ultrasonic sensor if there is an obstacle in close proximity to the vehicle. The ultrasonic sensor continually monitors the nervous surroundings for the purpose of obstacle detection. It's possible that the hurdle is a car that is getting closer to the emergency vehicle all the time. Following the realisation that the microcontroller enables the Li-Fi transmitter to deliver the required signal to the reception module, the LED of the transmitter is flashing with a variety of pulse width modulations (PWMs) depending on the information that is to be broadcast. The information about the gearbox is modified in accordance with the information that the emergency vehicle module has received from the roadside Li-Fi module. This information pertains to the particular road and lane number that is to be shown.