在引脚上使用 attachInterrupt
信号发生变化时立即运行代码
在引脚上使用 attachInterrupt 是 CoddyKit 上的免费 Arduino & IoT Academy 课时。 这是第 2 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Arduino & IoT Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Arduino & IoT Academy 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Wiring Code to a Pin
The attachInterrupt function tells your board: watch this pin, and the moment its signal changes, run my function right away.
Only Special Pins
Not every pin supports interrupts. On an Uno only pins 2 and 3 do, so plug your signal into one of those.
Translate Pin to Number
Wrap the pin in digitalPinToInterrupt so the right interrupt number is used. It keeps your code portable across boards.
digitalPinToInterrupt(2);Three Pieces
You give attachInterrupt three things: which pin to watch, the function to run, and the kind of change that should trigger it.
attachInterrupt(digitalPinToInterrupt(2), myISR, RISING);The Handler Function
The function you name is your handler, also called an ISR. The board calls it automatically; you never call it yourself.
void myISR() {
flag = true;
}RISING Edge
Pass RISING to fire when the pin goes from LOW to HIGH, like the moment a signal first switches on. 📈
FALLING Edge
Pass FALLING to fire when the pin drops from HIGH to LOW. A pull-up button often triggers here, since pressing pulls the pin down.
CHANGE Mode
Pass CHANGE to fire on either edge, both up and down. It is handy when you care about every transition of the signal.
Set It Up in setup()
Call attachInterrupt once inside setup, right after you set the pin mode. From then on the watching happens on its own.
pinMode(2, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(2), myISR, FALLING);The Loop Stays Light
With the interrupt attached, your loop no longer polls that pin. The handler runs only when the chosen edge actually occurs.
Turning It Off
If you ever need to stop watching, detachInterrupt removes the link. Most projects attach once and never detach.
detachInterrupt(digitalPinToInterrupt(2));Quick Check
Which trigger mode fires only when a pin goes from LOW up to HIGH?
Recap
You learned to call attachInterrupt with a pin, a handler, and a mode like RISING. Now hardware runs your code the instant a signal changes. 🎉
常见问题解答
「在引脚上使用 attachInterrupt」课时是免费的吗？
是的 — 「在引脚上使用 attachInterrupt」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Arduino & IoT Academy 课程的其余内容，请升级到 CoddyKit PRO。 Arduino & IoT Academy 课程共包含 4 节课。
「在引脚上使用 attachInterrupt」这节课中我会学到什么？
信号发生变化时立即运行代码 你通过在浏览器中直接运行的动手代码来练习 Arduino & IoT Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Arduino & IoT Academy 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Arduino & IoT Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 2 节课，共 4 节。
「在引脚上使用 attachInterrupt」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Arduino & IoT Academy 课中编写并运行代码吗？
能。每节 Arduino & IoT Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。