Programming via ISP

Programming via ISP can be complex when you're not used to it (I can tell you from personal experience). Apart from the technique I explain in the tutorial, there are a multitude of other ways to use the ISP protocol to inject code, I will not talk about these other methods, because not mastering them myself or not knowing them, it would be a waste of time for me to dwell on them.

• The first thing you have to be careful about, especially when you are not used to the Arduino IDE, is to check carefully if you can inject a simple sketch on your target that you want to transform into an ISP gateway.
  Hence the first use in the tutorial of the blink sketch (which I personally use systematically when I have a doubt about the injection, because it is the simplest sketch, which must always work).
  P.S. At this point if you want to use a Pro Micro card it does not have an integrated LED, as is usually found on other cards, and to do this test you will have to add an LED. The best is to do it at Pin 10. This is because it is the same pin that is used to know if the region code is injected inside the Playstation.
• The second thing to know is that when using the ISP protocol to inject code into a board, even if the Arduino IDE tells us that the injection was performed correctly, it can still be injected into a void! (Yes, it can't check if there's a board at the end of the chain).
  Hence a second use of the blink sketch in the tutorial, to once again verify that everything is working.