Introduction: DIY Li-Fi Using Arduino Uno

Picture of DIY Li-Fi Using Arduino Uno

Very simple and useful project to understand the working of Li-Fi, you can also make your own Li-Fi device with a bit more modifications to the design and code provided. You actually need two arduino's, one to send and the other to receive to make it more fun.

Step 1: ​Getting Started

Components needed

100 ohm resistor,

1 K resistor,



Arduino Uno

Step 2: Setting Up Connections

Picture of Setting Up Connections

Connect one end of 100 ohm resistor to pin number 13 and the other end to the positive terminal of led, the other end of led goes to GND pin. Also connect the ldr as shown. You can also use male to female jumper wires directly for connecting the resistor and ldr.

Step 3: Setting Up Even Light

Picture of Setting Up Even Light

As the ldr values depend upon the surrounding light and also led cannot emit even light I have used a small paper pipe and placed the led through one end and ldr at the other end of it.

Now you are all set to start coding.

Step 4: Code

//copy this code and start modifying

int sensorPin = A0; // select the input pin for ldr

int sensorValue = 0; // variable to store the value coming from the sensor

int light=0;

int i=0;

int d[32];

int temp=1;

int k=0; int add=0;

int a=1001;//-------------- replace with any value of your choice

void setup()

{ pinMode(13, OUTPUT); //pin connected to the relay

Serial.begin(9600); //sets serial port for communication


int b;



b=a%2; //converts binary to decimal







d[i]=sensorValue; }









} i--;

// for converting binary to decimal
















Serial.println(add); // Final recieved value gets printed

digitalWrite(13,LOW); }

void loop()



Step 5: Further Applications

You can make few changes to the code and make it work for characters and also you can use a light bulb instead of led which can give more light evenly than the led which is the actual concept of Li-Fi.



ATR0011 (author)2017-08-28

hey UdayN I would like to do this as a project...can u explain how I could transmit audio signal using the above lifi project , and one more thing is there a specific model of arduino uno that is required.Please reply as soon as you can

noahdekker (author)2017-03-04

does it work the whole process

abdulhye (author)2017-02-10

how can it receive data???

Tanmoy UnbeatableC (author)2017-01-04

does not work..

MaxV39 (author)2016-11-21

how do I make it send different information? it just sends a 14 and a 0

Allana37 (author)2016-09-23


FelixK14 (author)2016-08-29

there is something wrong in the script: if i unplug the ldr, the serial monitor still shows my value "a"

UjasP2 (author)2016-05-23

What is the value of capacitor used ?

KiloVision (author)2016-03-21

FYI, visible light is not 100x faster than radio waves. Both travel at the speed of light.

UdayN (author)KiloVision2016-03-21

Yeah, it's actually the spectrum of light which is 10,000 times larger than the radio waves we use for Wi-Fi, which makes Li-Fi 100 times faster

ThomasK19 (author)2016-03-20

I know WiFi. But what is Li-Fi?

UdayN (author)ThomasK192016-03-20

Li-Fi uses visible light to transmit data at very high speed and is 100 times faster than Wi-Fi, which uses radio frequency.

ThomasK19 (author)UdayN2016-03-21

Hehe. 9600 baud is definitely more than 100 times slower than WiFi xD

UdayN (author)ThomasK192016-03-21

This project is just to understand the concept of Li-Fi and send some data using light and not to compete with their baud rates. But in general Li-Fi is 100 times faster than Wi-Fi.

ThomasK19 (author)UdayN2016-03-21

I was just kidding ;-) But really, this is a light morse, rather than Li-Fi for which you would need to implement something like 802.11.

ThomasK19 (author)UdayN2016-03-21

Ah. What sometimes is used between buildings with a laser. You probably need some special transport protocol to eliminate blackouts cause by birds?

ThomasK19 (author)ThomasK192016-03-21

To answer my own question:

DIY Hacks and How Tos (author)2016-03-19

Cool Li-Fi project.

About This Instructable



Add instructable to: