Try the code, read the why
Pick an example, change the numbers, and press Run to see what the Serial Monitor would print. Every snippet comes with an explanation of what each part is doing — no code dumps.
The idea: The 'hello world' of electronics. Switch pin 13 on, wait, switch it off, wait — forever.
playground.ino
Serial Monitor
Press Run to see the output…
This is a friendly simulation of what the Serial Monitor would show. To run it for real, paste the sketch into the Arduino IDE and press Upload.