loop() ทำงานตลอดไป

After setup finishes, the second block takes over. Meet loop(), the part of your sketch that never stops running. 🔁

The key idea: loop() repeats endlessly. The board runs it, reaches the bottom, then jumps straight back to the top.

Just like setup, it returns void and holds your code inside curly braces. This is where your device's behavior lives.

Order matters. The board runs setup() once, then hands control to loop forever. They are partners, not rivals.

Inside loop you might turn an LED on, wait, then off. The board repeats this, so the light blinks again and again.

Because loop runs constantly, it can check sensors thousands of times a second. That is how your device stays responsive to the world.

You do not write your own forever-loop. Arduino already repeats loop() for you, so just describe one pass of behavior.

loop only stops when power is cut or the board resets. As long as it has power, your loop() keeps cycling.

Lines in loop run top to bottom each pass. Rearranging them changes the sequence of actions your device performs.

An empty loop() compiles fine, but your device just sits idle. The braces are still required even with nothing inside.

Every Arduino program needs both blocks: setup() to prepare and loop() to act. With these two, you can build anything.

Let's check how loop() behaves.

You learned that loop() runs forever after setup, repeating top to bottom. It is where your device senses and reacts on every pass. 🎉