Data communication using LiFi technology and Microcontroller

 Introduction of LIFI Technology

Data communication using LiFi technology and Microcontroller

The light fidelity (LiFI) technology is actually light communication technology in which signal is transmit and received by using medium of light. The communication speed of data transmission is very high as compared to WiFi. The LiFi data is transmitted using Light Emitting Diodes (LED) in digital format consisting of bit streams whereas the receiver of LIFI uses an IR detector. The receiver is connected to microcontroller which decodes the message into again digital format in bit and bytes. The whole transmission in LiFi protocol is carried out digitally means that the bit representation logic zero ie “0” lighting emitting diode OFF and logic one i.e “1’ reflects that the lighting emitting diode is ON.

The Lifi encoder and decoder both are interface with microcontroller means that it is MCU which actually controls the Transmitter and receiver for proper functionality of communication. The MCU are programmed using suitable programming language like assembly, basic or C, the code is compiled and burned into the microcontrollers.  Here it may be noted that the power of transmitter depends upon the distance travelled by the light to reach the receiver, one can use small LED if distance is short and if distance is larger than very high power intensity light source like high power bulb or LED will be required to use as LiFi transmitter. Whereas in the receiver section photodiode module or IR module is used to detect the light signal generated from LiFi transmitter, again the quality of receiver will be very important. The signal required to transmit through this protocol may be a text message, may be an audio signal or other.

As discussed above the LiFi technology required the use of light for transmission of signal which could a LED or torch bulb or any suitable, then its driver circuit will be required to design accordingly. The driver circuit of transmitter will mainly depends upon the power of transmission i.e. power consumption of light source; rated power transistor on proper heat sink will be required to use in order to avoid damages of components. Similarly the power supply modules will be designed in order to meet the requirements of transmission power if LIFI transmitter. This is optical wireless communication technology on high speed communication via visible light communication which works by switching the light source OFF and ON at very high speed by control circuit usually power modules and microcontroller. Due to very fast communication speed, the ON & OFF patterns cannot be noticed by the human eye. There is an advantage of use of LiFi communication protocol in sensitive areas with respect to electromagnetic waves. Where interference of electromagnetic waves is required to avoid  like hospitals, industry and high profile machinery. The transmission spectrum of WiFi and LiFi is electromagnetic spectrum to transmit information, the WiFi uses radio waves where as the LiFi uses visible light. In the LiFi communication the signals are transmitted via light through wireless channels to the receiver.                                

LIFI BLOCK Diagram of Transmitter and Receiver LED IrD

Other protocol for effective communication are listed as The Free-space optical communication, Bluetooth, The Indoor positioning system (IPS), The Infrared communication IrDA, The Near Field Communication (NFC),The Wi-Fi positioning system, The Spatial light modulator (SLM), The Super Wi-Fi, The Wi-Fi Direct and the Wi-Fi.

Advantages of LiFi communications over other communication protocols:

There are many advantages of LiFi technologies over other listed above in many ways, some of the advantages of LIFI are listed below:

• Communication Speed: High Speed Transmission
• Media of Communication Light: means Wireless system that is No Wires Needed for transmission
• High Reliability of Communication means chances of data loss minimum.
• Cost : The development cost of this project is very low as compared to other costly technologies

Example Projects using LiFi Technology :

Here we will discuss the following two projects to demonstrate the use of LiFi technologies and there components required are listed along with the title of the project of Lifi and microcontroller.

1. LiFi Data Transfer System for Text Messages
2. Use of LiFi Data Transfer System for Temperature measurement at distance

The details of both Microcontroller projects are discussed as under one by one.

LiFi Data Transfer System for Text Messages

Here we are using some text message required to transmit over a small distance wirelessly using LiFi technologies, it implies as The text generated on transmitter side will be proceeded in microcontroller and through switching transistor and LED will be transmitted at the other hand the receiver based on IR diodes will detect the signal and read it, data will be processed in microcontroller. At the end message will be display on LCD.

Components used in this microcontroller project:

The following components will be used in this project.

·       Microcontroller 02 Nos , on choice of project builder may be 8051, At89c51, MicroChip PIC microcontroller or Atmel AVR or Atmega, or Arduino, one for transmitter section and one for receiver section as shown in the block diagram.

·       Key switch mainly the Push Buttons as required

·       LDR Sensor 01 Nos

·       LED

·       Switching control circuit for Light Source i.e. LED driver mainly consisting of a few resistor and transistors.

·       Receiver circuit for reciver i.e. LDR driver mainly consisting of a few resistor and transistors.

·       PCB Board to mount the components

·       Resistors as per requirement

·       Capacitors as per requirement

·       Transistors as per requirement

·       Cables and Connectors as per requirement

·       Crystal for Microcontroller 02 Nos

·       Power supply for both transmitters and receiver circuits        

Use of LiFi Data Transfer System for Temperature measurement at distance

Here we are transmitting the measured temperature over a small distance wirelessly using LiFi technologies, it implies as the temperature sensor will measure the environment temperature, ADC will convert the measured analog temperature to digital, microcontroller will processed the signal and LED will transmit it. The receiver based on IR diodes will detect the signal and read it, data will be processed in microcontroller and at the end the value of temperature will be display on LCD.

Components used in this microcontroller project:

The following components will be used in this project.

·       Microcontroller 02 Nos , on choice of project builder may be 8051, At89c51, MicroChip PIC microcontroller or Atmel AVR or Atmega, or Arduino, one for transmitter section and one for receiver section as shown in the block diagram.

·       Key switch mainly the Push Buttons as required

·       Temperature sensor like LM35

·       LDR Sensor 01 Nos

·       LED 02 Nos

·       LED driver circuit.

·       LDR driver circuit.

·       ADC (analog to digital converter) like ADC0804

·       PCB Board to mount the components

·       Some Transistors, Resistors and Capacitors as per requirement

·       Crystals for the operation of Microcontroller 02 Nos

·       Power supplies for both transmitters and receiver circuits