So he figured out that model remote and found sample code? So then how did the first person get the sequence? Did they sit there with an IR detector and scope and count each pulse? Is there a way to record and play back like on those 3 in one "learning " remote controls through the scope?
The remote that come with the generic Arduino is amazingly bright. I hooked a sensor to a simple transistor circuit and could get the LED to blink with the remote bouncing off two walls at a distance of 50' or so. Are our eyes just not that sensitive to color LED's or are they just not that bright?
Once you know which 'family' of IR remote you have, it is pretty easy to buy an
IR receiver and hook it up to a uC (Arduino will probably work well) and trap the codes versus button pushes. This type of thing has been done for quite a long time and Google will probably turn up a lot of projects.
Like this:
https://learn.adafruit.com/using-an-infrared-library/hardware-neededThere are a few different protocols and apparently the Arduino library knows how to detect them.
We can't see IR at all. If the transmitting device is truly IR, we won't see it. However, we can use our cell phone cameras to see it - same with other digital cameras.
A simple photo sensor is not a good substitute for an IR receiver. Among other things it won't be looking for the 38 kHz carrier.