So this is a somewhat off the cuff question, or discovery, or just a curiosity. I have been working with the Arduino platform and projects for a couple of months now, great education, thought provoking, and just plain fun for these isolate at home times. Anyway, I did the typical "kits" approach to start with. I came to the IR code experiment and thought it was pretty neat to see the actual codes. With an engineering background I knew the basics of the IR remote and now I can see the actual codes from the various remote makers, cool. So then I put together an uno running the basic blink program and attached a standard IR led in parallel to the visible led. I used a second uno to run the typical IR code receiver experiment. Of course, the blink, blinks and the IR receiver, receives.
My question comes in with what exactly the standard IR led in its blink process is creating. I opened the serial monitor for the IR receive uno and observed the string of numbers (I created both HEX and DEC outputs). The thing is, I have been unable to find any duplicate numbers? In other words I have let the simple blinking IR led run for a great deal of time, generating a great deal of numbers on the IR receive side. I have started and stop the process numerous times. I capture the numbers into a spread sheet to analyze and, at least each time I have done this the numbers are all unique. Numbers between captured runs are also unique to each other. The decimal numbers generated are all either 9 or 10 digit unique numbers. Typically computer generated random numbers are not actually totally random, thus the use of 'seed' programs for computer random number generation.
Of course there is nothing terribly important or earth shattering about this question but hopeful someone in the Arduino community can tell me where the numbers in my little experiment are coming from, and why they always seem, at least in my experience, to be unique? Is there something in the architecture of the uno on the IR receiving side that would happen to 'choose' the numbers to spit out to the serial monitor or is it just noise that I am capturing? I guess if these numbers always come out unique it could have some application as a random number or random seed generator. Otherwise it is just a curiosity. Thanks.