LiFi Circuit for Transmitting USB Data

If you are wondering how a LiFi concept could be used for transmitting USB data, this article will provide with all the details you required.

We know that a Li-Fi concept is used for transmitting  a digital data across a given premise  more efficiently than any other means invented so far, especially because the Li-Fi idea allows the user to transmit the data and additionally illuminate the area where it's been installed, so it's like getting two crucial benefits from a single unit.

Remember our age old film projector device? It's probably the oldest known method of using light for transmitting data (picture).

Although we always had other great means of transmitting wireless data such as Wi-Fi technology, RF circuits, etc, using light for this purpose was never imagined simply because lights have been always considered as low-tech units, and thus underestimated, until the day when Mr. Harald Hass discovered this hidden potential of lights (LEDs), and showed the world how LEDs could be actually used for transmitting data in a much efficient way than any other contemporary techniques.

In one of our earlier articles we learned through an example circuit regarding how to effectively transmit audio signal through a Li-Fi, in this article we'll go a little further and learn how to transmit an USB signal through Li-Fi.

Since LEDs are semiconductors devices these become perfectly compatible for handling digital data without any form of distortions. An LED will replicate and transmit the input content exactly as it was in the original source, and this property make LEDs extremely easy to configure for the intended purpose.

LiFi USB Transmitter Circuit

The following figure shows a simple Li-Fi transmitter circuit which can be used for communicating with USB signals inside a room or an confined premise.

USB Li-Fi Transmitter circuit

The circuit is self explanatory, the USB data is fed to the base of the BC547, which is further transferred to the LED for the required Li-Fi transmission.

LiFi USB Receiver Circuit

The following diagram presents the USB Li-Fi Receiver circuit

LiFi USB Receiver Circuit
PLease connect a 1K resistor between positive and collector of the transistor to safeguard the opto LED

The Li-Fi USB receiver circuit is yet another simple design which incorporate a basic LDR sensor for detecting the Li-Fi signals from the transmitter LED. The LDR info is further conveyed to a opto coupler stage for producing the final amplified output at the emitter of the BC547 Darlington transistor.

The data is subsequently sent to a USB demodulator or the USB processor stage for the final extraction.

8 thoughts on “LiFi Circuit for Transmitting USB Data

  1. Have questions? Please feel free to post them through comments! Comments will be moderated and solved ASAP.
  2. sir, for transmitting audio signal according to lifi I have used your circuit but led is blinking with the audio music…how can I solve this problem….and some noise are created with the music in output.

    • Joydip, you will have to create a carrier wave and mount the audio signal on this carrier wave in order to prevent fluctuations in the light and noise at the output…if possible I'll try to update the idea soon in a new article.

    • Dear zheyi. i am glad yo liked my article,

      opto coupler is small IC like device having an internal LED and a light sensitive transistor packed inside the iC, when the led is triggered with an external DC, the transistor activates…in this two sections of a ciruit can be connected without physically connecting the two stages using an optocoupler

      the data from a computer or cable network can be a multiplexed data having many different frequency based information passing through the same wire simultaneously

  3. Sir Swagatam, I liked your articles concerning Li-Fi, if its no trouble for you to give me your email and ask some questions regarding Li-Fi it will be greatly appreciated. I plan to pursue to this line of topic for our thesis, we could be the first one to have this kind of topic in our university so it would be greatly appreciated if you could help us. Thank you

    • Hi Nathaneil, i will surely help you, but you may have to post your questions here through comments so that other readers also get the opportunity to learn through our discussion…



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