Visible Light Communication

Project Title

Visible Light Communication

Project Area of Specialization Internet of ThingsProject Summary

Today technology is witnessing major changes; it is predicted that Li-Fi will make a big leap in Internet services it is a practical and successful substitute to traditional Wi-Fi that uses radio waves. This makes Li-Fi the future of wireless Internet service. Practically every LED can be considered as a Li-Fi Access Point “AP” which means wherever there is light, there will be Li-Fi service (i.e. Internet Services). Line of Sight “LOS” is considered to play a major limitation in Li-Fi services thus more research is required to overcome this obstacle in order to make Li-Fi much easier to install and apply. As a future trend, Li-Fi will be considered, majorly, an ideal in terms of high data rate transfer for internet and their services. The Li-Fi new vision is based on real solutions to spectrum broadness and to achieve the coverage in certain places where radio signals can reach.

Project Objectives

Visible light Communication is communication through LED light

Project Implementation Method

The task of the transmitter is to convert digital data into visible light. An LED was a suitable component because of its relatively linear relationship between current and light intensity. The general idea is to modulate the light intensity of the LED i.e.; the intensity of the light corresponds to the symbol transmitted. The Arduino ports are not capable of delivering the right amount of current to make the light intensity strong and fast enough. To get around this problem a transistor is used as a switch, which made it possible to switch a larger current faster. In Figure 10, a schematic is shown to give an overview of the transmitter. The PCB for the transmitter is designed using the following steps:

1) The transmitter PCB design was done by converting the circuit’s schematic diagram into a PCB layout. The software used for PCB layout is Cad soft Eagle.

2) After designing the PCB layout, the printout of the circuit board is taken out on glossy paper.

3) Then the copper plate is cut for the circuit board. Also, the top oxide layer is rubbed away.

4) After this, the PCB print is transferred onto the copper plate.

5) Next, the circuit from the paper is ironed onto the PCB plate.

6) Next step is to etch the plate.

The receiver converts the incoming light into current using a photodiode. For a digital signal, the Arduino cannot receive a voltage above 5 V. Therefore, the electrical circuit between the photodiode and the Arduino needs to process the electrical signal so it can be interpreted correctly. The receiver’s electronics need to convert the current to voltage in order to amplify and compare it. Distance between the transmitter and the receiver can be varied, but in order to avoid too small or too high signal, an automatic gain controller (AGC) can be designed, instead, a variable resistor is used here. This component amplifies or reduces the input voltage to a selected output voltage. To make sure the signal is digital and stable before the Arduino, an Op-Amp comparator is used here.

Benefits of the Project

A. Underwater Communication

Using RF signals is impractical due to strong signal absorption in water. Li-Fi provides a solution for short-range communications. Submarines could use their headlamps to communicate with each other, process data autonomously and send their findings periodically back to the surface in Underwater Remotely Operated Vehicles (ROV). Another important issue is that Li-Fi can even work underwater where Wi-Fi fails completely, thereby it’s open for military operations.

B. Traffic Management

Li-Fi can help in managing the traffic in a better manner and the accident numbers can be decreased. Traffic lights can communicate to the car and with each other to manage the traffic in the street. A traffic light can play the role of the sender of the data to provide information to the car on the status of the road or about the situation of other cars as shown in Figure 4. Also, cars can communicate with each other and prevent accidents by exchanging information. For example, LED car lights can alert drivers when other vehicles are too close.

Technical Details of Final Deliverable Today technology is witnessing major changes; it is predicted that Li-Fi will make a big leap in Internet services it is a practical and successful substitute to traditional Wi-Fi that uses radio waves. This makes Li-Fi the future of wireless Internet service. Practically every LED can be considered as a Li-Fi Access Point “AP” which means wherever there is light, there will be Li-Fi service (i.e. Internet Services). Line of Sight “LOS” is considered to play a major limitation in Li-Fi services thus more research is required to overcome this obstacle in order to make Li-Fi much easier to install and apply. As a future trend, Li-Fi will be considered, majorly, an ideal in terms of high data rate transfer for internet and their services. The Li-Fi new vision is based on real solutions to spectrum broadness and to achieve the coverage in certain places where radio signals can reach. Final Deliverable of the Project Hardware SystemType of Industry Education , IT , Medical , Petroleum , Agriculture , Energy , Manufacturing , Transportation , Media , Others , Health , Security , Telecommunication Technologies Internet of Things (IoT), Augmented & Virtual RealitySustainable Development Goals Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	9500
Node-MCU esp8266	Equipment	4	1500	6000
photo diode	Equipment	5	500	2500
batteries	Equipment	10	100	1000