Introduction: LiFi: Transmit Music Using Light
In this instructable I will show you how to convert music to varying light intensity and then transmit it wireless using an LED and a solar cell whose output it seen by a speaker.
Step 1: Demonstration
Step 2: Parts Required
- 9V Battery
- Alligator wires
- Leds (here I use an emergency led light)
- Solar cell (Preferably above 2V)
- 3.5mm audio jack to be connected to mobile
- Speaker
Step 3: Transmitter & Receiver
Connect the 9v battery in series with the audio jack then connect it to the led.
The tip of the speaker jack is connected to positive of the solar cell and negative is connected to the body.

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24 Comments
6 years ago
please send me its pdf at ranjanshobhit510@gmail.com
6 years ago
Wont the 9 volt end up frying your phones sound card.
Reply 6 years ago
I need full pdf
6 years ago
can i use LDR instead of solar cell?
Reply 6 years ago
Yep, but you should connect a battery in series with it.
Reply 6 years ago
How many volts should the battery be?
7 years ago
Hey, just had a question. How do I connect everything, the pictures are a little blurry and can't figure it out.
Thanks
Reply 7 years ago
Thanks for the feedback! I will be uploading a circuit diagram soon.
Reply 7 years ago
could you upload a circuit diagramm soon?
Reply 7 years ago
Could you please post the diagram soon. I have a school project that's due soon and I really wanted to use this as a demonstration. I'd greatly appreciate it.
Thanks
7 years ago
muy buena canción¡¡¡ :v
7 years ago
how did you modulated the signal at LEDs during transmission?
Reply 7 years ago
The phone's audio jack converts a song to an analog signal output to drive the LEDs
Reply 7 years ago
Does this mean you can use any LED, or does it have to be one with a circuit like the one shown in the pictures?
7 years ago
Would a light dependant resistor (LDR) be convenient for this type of communication? Or is a photodiode better?
Reply 7 years ago
A photo-diode would be better as it has faster switching time.
7 years ago
Would a light dependant resistor (LDR) be convenient for this type of communication? Or is a photodiode better?
7 years ago
Hi.
You use a microcontroller before transmitting the signal for the LEDs?
Reply 7 years ago
No a micro-controller is not required.
7 years ago
Hello.
You use a microcontroller before transmitting the signal for the LEDs?