Introduction: TRANSMIT DATA THROUGH LIGHT !!!
Hello guys, after a long time I am back again to share a new and simple project. In this project I will show you how you can transmit data signals from one place to another through Light. Sending data over light isn't a new concept but recently it gained a lot of attention after the introduction of LIFI . In this tutorial we will transmit simple data like Binary and Audio through LEDs and Laser.
So lets get started....
Step 1: GATHERING COMPONENTS :-
- BD139 Transistor. (Any NPN transistor will work. 2N2222 can be used)
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Link for Europe - LED or Laser.
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Link for Europe - Two 1k Ohm resistor.
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Link for Europe - 50 and 100 Ohm resistors each.
- Switch.
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Link for Europe - 10k Ohm Potentiometer.
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Link for Europe - Arduino (Optional. If you want to experiment with different data.)
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For Receiver:-
NOTE:- If you have computer speakers you don't need to make a Receiver. But you will need Solar cell or LDR to receiver Light signals.
- Two BC547 / 2N2222 transistors.
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Link for Europe - 1k and 10k Ohm Resistors each.
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Link for Europe - 1uf Capacitor.
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Link for Europe - Speaker.
All the components can be bought at UTsource.net
Step 2: MAKING THE TRANSMITTER :-
The setup is simple. Just follow the circuit diagram I have provided. For a reference check the Breadboard Layout. Here I have usedBD139 transistor but you can use any general purpose NPN transistor, just take note of the Pin out diagram of it. Also power the circuit with 5v - 7v depending on what you are using ( Laser or single LED).
Once the circuit is ready. Power it up and see if the light glows. If it does then turn the potentiometer to check if the intensity of light changes. If it does, Everything is fine and you can proceed to the next step.
If it does not work check the connections and polarity of the transistor.
Step 3: MAKING THE RECEIVER :-
Just in case you don't have a Computer speaker or you just want to make this full "DIY Project", You can follow the circuit given above to make a simple audio-amp.
If you have a computer speaker things are pretty simple in this step. just use a Female Audio jack and connect it with two wires to a solar Cell or LDR and plug the speaker. that's all here.
Step 4: HOW TO USE IT ???
Once the Transmitter and Receiver are made just connect the earphone Jack to any music player or a mobile phone and play a song. Adjust the Potentiometer to dim the LED, You will notice it flickering. If it doesn't recheck the connections and try again. When it flickers it means the sound is been converted to digital signal and transmitted via light.
Now just place the solarcell or LDR near the LED and you will hear the music being played on the speakers. Adjust the brightness of the LED to get a more clearer sound. For long distance transmission use a laser.
Now that you have successfully transmitted audio, You can experiment with different type of data using Arduino. To connect it to an arduino just connect the GND pin of arduino to Ground and Input pin of capacitor to any Digital pin of arduino and set the pin to transmit data. But to decode these signals of arduino you will need another Arduino at receiving end. But that's for another Instructable. Till then try this and experiment more...
I hope the instructions are easy to understand. If you have any questions feel free to ask in the comments.
22 Comments
Question 2 years ago
Can you suggest me to do this project still more effectively sir (means using some other equipments).... Is there a way u can help me plz ....
Question 4 years ago on Step 4
Can you please Give coding for using arduino
Question 4 years ago
sir i want to make this project using two arduino s..what should i do?? please rply sir.
Answer 4 years ago
You want a full duplex communication, I suggest you do some research about it. And you will understand how to make this project
4 years ago on Step 4
sir..please..i want to make this project ..i want some more information..at the transmitting end a led and at the recieving end using ldr ,want to light the another led..
https://m.youtube.com/watch?v=TiUcxgX2_UQ
please help me sir..
Reply 4 years ago
sir in your project what are the codes when i use two arduino s..
4 years ago
hello
actually its wonderful way to learn deeply the nature of transmitting and receiving using electromagnetic waves for analog and digital input signals.Also the simplicity .
could I use IR led or antenna as RF.so what are the factors should be taken in consideration?
could I try this by simulation, if yes which one?
Thanks alot.
Reply 4 years ago
Yes you can use IR LED to transmit sound in same manner shown above , just replace normal LED with IR LED and replace the LDR/solar cell with an IR receiver.
To use RF communication, this circuit will not work, though you can use a micro controller like arduino for that.
Question 5 years ago
we have connected the transmitter circuit as shown in the circuit diagram, but the LED doesn't light up when power is supplied. We tried changing polarity of the transistor and checked the circuit connection repeatedly but still didn't work. What can be the possible cause?
Answer 5 years ago
Sorry for the late reply,
have you tried turning the potentiometer to check if the LED lights up. also the LED will not work until you supply an audio signal. If you tried it all and still it doesn't work try replacing the transisor.
Reply 4 years ago
Thank you for replying. Yes, the transmitter worked, but we are not getting any sound from the receiver speaker, not even noise, though we know the receiver circuit is not faulty cos it gives a vibration when the ldr is illuminated with a torch.
Reply 4 years ago
LDR should technically work but I never used it as it has a small surface area.
I used a small solar cell, You can give it a try. If you dont have one, you can get one out of an old solar powered calculator.
Question 5 years ago
Hi Sir..!! i have successfully connected all the components and powered it on but the led just blinks once and goes off.... and then i tried powering on again but the same error occurs...... plz help me solve this problem...
Answer 5 years ago
If you have used same components and followed the instructions correctly such error should not occur, I cannot help without looking at your connections. I suggest you trouble shoot the circuit once again and if you cant find error. post some pics of your build so I can have a look at it.
Reply 5 years ago
I'm sending some photos plz help me...
Reply 5 years ago
the connections doesn't seem right. go through the diagram again and make the connections properly.
Question 5 years ago on Step 4
sir i made the project but i am getting full of noisy signal and the sound was too low .How can i over come this to get a good communication medium...
Answer 5 years ago
Reduce the ambient light by making the room a bit dark. Then Adjust the Potentiometer slowly until you hear clear sound.
Question 5 years ago
Hey this project seems nice but I realised it and I have a little problem. When I see the Led flickering, and I put the solar cell just upon it, I can't hear any change of noise and just a rustle, do you have any idea of what could be the problem here ?
Thanks for this
Answer 5 years ago
Try increasing the intensity of the light.