I made an analog circuit after seeing it online to transmit sound with cheap laser pointers. Now I want to upgrade that to a college project in which I can do digital communication between two arduinos and show its practical utility as a communication link.
This is how I think it should be connected. I will connect Tx pin of transmitter to a circuit to produce correct voltages for the biasing of laser. At receiver input will strike a small calculator solar panel or an LDR, a schmitt trigger will be used to change the levels to correct TTL after reception and then it will be given to Rx pin.
Now, I haven't done much programming in arduino or any microcontroller for that matter, but once when I was doing something like this using arduino I noticed that during serial communication it will continuously spit 0s or 1s depending on pull up or pull down even when no data is coming.
How can I implement something like a start and stop bit so that the arduino only responds when a correct byte is received.
Basically I want to give some input through a keypad or something from the Tx and display that input on an LCD at Rx or control some devices based on what input is coming.
Alright. Thank you very much. I will try this to work out as soon as I finish building my s3v3. I already have a UNO, then I will update the results here.
And as for the Photodiode and Photo transistor, I have got both of these, I will try both. Thanks for the tip
Another good site (if you want to see the "extreme" version of what you are trying to do):
Something to keep in mind - at the receiving end you may want to use a lens (cheapo magnifying glass lens will be OK), depending on the distance covered...
