Hey guys i want to do a lifi based project for my engineering and i don't know where to start.

1. i want my project hardware to transmit data from one PC to another and vice-versa using light as transmission media..(no optical fiber)
2. i want to do a bidirectional system.

I hope the above brief explanation works to explain if now please read the below in detail explanation.

I have a text/video file in PC1 and i want to transfer data to PC2. At transmitter end I want to driver an LED to flicker according to the binary bits representation of data(video/text) and receiver end i want the photo diode to recognize and decode the data.

so here are my concerns I have a driver circuit but i dont know how to provide i/p to the driver from the PC!!??
how does the 2 system intercommunicate do i need an GUI application to do the operation?

i have 2 many questions i hope some one answers my question and help me.

Thank you
-Manohar

 

If you don't already understand how a system like this may work then maybe you'd be better off choosing a different project.

However, to answer you question. The hardware would be very simple (serial encoder/decoder), the system would mostly come down to software.

 

If you don't already understand how a system like this may work then maybe you'd be better off choosing a different project.

However, to answer you question. The hardware would be very simple (serial encoder/decoder), the system would mostly come down to software.

Why on earth are people so discouraging ?????? Everybody has to start somewhere.

 

It's not discouraging....
It's just that we will not design it for you.
We are here to help.
You start, then we can guide you.

 

Why on earth are people so discouraging ?????? Everybody has to start somewhere.

I didn't mean my response to be discouraging, rather urging you to start off with something simpler as what you have chosen is vastly complicated, especially for a beginner.

If you insist on diving in at the deep end then why not look into fibre optic communications? What you're attempting to do is exactly the same, only you're focusing the beam of light instead of guiding it through a fibre. This will actually only further complicate things as you'll have to incorporate additional filtering and noise reduction, your light source will also have to be extra powerful to account for looses that would otherwise be non-existent in an optic fibre.

 

@TheButtonThief
Why are you discouraging OP again.

 

I didn't mean my response to be discouraging, rather urging you to start off with something simpler as what you have chosen is vastly complicated, especially for a beginner.

If you insist on diving in at the deep end then why not look into fibre optic communications? What you're attempting to do is exactly the same, only you're focusing the beam of light instead of guiding it through a fibre. This will actually only further complicate things as you'll have to incorporate additional filtering and noise reduction, your light source will also have to be extra powerful to account for looses that would otherwise be non-existent in an optic fibre.

Well frankly speaking i dug my own grave so now there is no backing off since i have already submitted synopsis(i know i didnt think about it prior and am stupid) to my prof who doesnt want to back off.... sorry for being rude mate but i cant back off now.

 

It's not discouraging....
It's just that we will not design it for you.
We are here to help.
You start, then we can guide you.

No i dont want you to design it for me all i want to know is few info to start with thats it.

 

Think about what interfaces on a computer can send it's signal on one wire as you can only drive one wire from the output of a photo diode or photo transistor. (For one direction of communication)

Les.

 

Think about what interfaces on a computer can send it's signal on one wire as you can only drive one wire from the output of a photo diode or photo transistor. (For one direction of communication)

Les.

An LED can be a photodetector. It makes an interesting project if he wants to do one optical device per device.

 

Maybe you can use a couple of USB-to-Serail converters. Using terminal software that can capture and send files as well as service the keyboard and display on both PC's simplifies the problem to that of getting the one's and zeros from the serial outputs into an optical signal then back to electrical serial data (most commonly 0 to 5V or 0 to 3.3V). If you make is simplex (only one end transmits at a time, life becomes relatively simple and you would not need microcontllers and firmware in the path.



In this circuit the receiver can be as simple as a photo transistor and the receiver can be as simple as an LED.

http://www.epanorama.net/circuits/laserlink.html
You should be able to find many examples on the internet. Google is your friend

 

Maybe you can use a couple of USB-to-Serail converters. Using terminal software that can capture and send files as well as service the keyboard and display on both PC's simplifies the problem to that of getting the one's and zeros from the serial outputs into an optical signal then back to electrical serial data (most commonly 0 to 5V or 0 to 3.3V). If you make is simplex (only one end transmits at a time, life becomes relatively simple and you would not need microcontllers and firmware in the path.

View attachment 121279

In this circuit the receiver can be as simple as a photo transistor and the receiver can be as simple as an LED.

http://www.epanorama.net/circuits/laserlink.html
You should be able to find many examples on the internet. Google is your friend

Hola Dick

Aren't the laser xmtr input pins reversed? BC 337 is a NPN, right?

As my ex (and her mother) used to say, I am wrong most of the time. If so, sorry.

 

Hola Dick

Aren't the laser xmtr input pins reversed? BC 337 is a NPN, right?

As my ex (and her mother) used to say, I am wrong most of the time. If so, sorry.

I think the GND and TXD labels need to be flipped.

If you zoom in on the image, the transistor is an NPN. (BC337).

 

Hey...not my circuit! Though I acknowledge my responsability in posting a schematic an error. For that I apologize.

The laser and BC337 are connected correctly.

Yes, the GND and TXD connections are mislabeled as GopherT noted.