[URGENT]Visible light communication using arduinos , LED & photodiodes

Hello everyone
I am trying to begin making my final year project on visible light communication. I want to use 1 arduino on Tx side and another on Rx side.The Tx side has an LED which flickers, based on the text we want to send to the other arduino. The other arduino has a photodiode, which detects the variation of LED and the arduino on the Rx side translates these captured flickers to the message that was sent. The photodiode decodes the flickers by mapping it to the corresponding ASCII code.

Please help on how to proceed with the project.

Google " IRDA"

I didn't get you

No, I don't want to use infrared LED. I want to communicate using visible light. Please help me in doing that.

I didn’t get you

Well, it can’t be that urgent, I guess.

Google “LiFi”

Although this speaks of infrared, there is no reason why you should not be able to adapt it to visible light.
I remember having to change the resistor values when I did something similar.

You are doing exactly the same thing as an IR remote control, except you want to change the wavelength of the light used. I would use the IR libraries and change out the hardware to visible light compatible parts. Transmitter and receiver will likely have to be really close to each other since you are losing all the benefits of IR, namely the rejection of ambient light.

When I was a kid I had electronic experiment books that included talking over a flashlight beam. Very similar to the sound track on the "talkie" movies. Maybe put an optical isolater between the serial tx and rx and call the project done.

When I was much younger, we played (at night) with light beam communications. My receiver focus mechanism used the vernier rail from a WWII bomb-sight and the phototransistor was a "Modified" OC71 - i.e,, the black paint was scraped off. :grinning:

The transmitter was of course, a torch bulb fed from a modified valve radio with DC "carrier" bias applied.