Imagine that you have followed carefully the
Blink250ms project, everything is wired correctly, you double-checked that, and the code seems okay too, but it doesn't work.
Our LED isn't blinking at all. How to be sure that the
loop() structure of your code is correctly running? We'll modify the code a bit in order to trace its steps.
Here, in the following code, we'll add serial communication for the LED to blink every 250 ms:
It is good practice to start from an already existing code, to save it under another name, and to modify it according to your needs.