读取 PIR 运动传感器
检测移动，并调节灵敏度和延迟
读取 PIR 运动传感器 是 CoddyKit 上的免费 Arduino & IoT Academy 课时。 这是第 1 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。
What a PIR Detects
A PIR sensor watches for changes in infrared heat. When a warm body like a person moves across its view, it fires.
Why It Sees Movement
PIR stands for passive infrared. It only reacts to a change in heat, so a still object soon fades from notice while motion stands out.
It Has Three Pins
A typical PIR module has three pins: VCC for power, GND for ground, and OUT for the digital signal you read.
Power It Up
Most PIR modules run on 5V. Connect VCC to 5V and GND to ground, just like any other digital sensor.
OUT Is Digital
The OUT pin gives a clean digital signal. It goes HIGH when motion is detected and LOW when the area is calm.
Set the Pin as Input
Tell the board that the OUT pin is an input so it can listen. Do this once inside setup().
pinMode(2, INPUT);Read the Motion State
Read the sensor with digitalRead. A returned HIGH means it just sensed movement nearby.
int motion = digitalRead(2);Act on Detection
Wrap the reading in an if check so your code does something, like light an LED, only when motion is HIGH.
if (motion == HIGH) {
// movement detected
}Tune the Delay Trim
The on-board delay trimpot sets how long OUT stays HIGH after motion. Turn it to hold the signal longer or shorter.
Tune the Sensitivity Trim
The second trimpot adjusts sensitivity, the range at which motion triggers. Lower it to ignore far-off movement.
Let It Warm Up
Give a PIR up to a minute to calibrate after power-on. Early readings can be jittery until it settles.
Quick Check
What does a PIR sensor actually respond to?
Recap: Sensing Motion
You wired a PIR with VCC, GND, and OUT, read it with digitalRead, and tuned the delay and sensitivity trimpots.
常见问题解答
「读取 PIR 运动传感器」课时是免费的吗？
是的 — 「读取 PIR 运动传感器」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。
「读取 PIR 运动传感器」这节课中我会学到什么？
检测移动，并调节灵敏度和延迟 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 1 节课，共 4 节。
「读取 PIR 运动传感器」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。
此课程中的所有课时
- 读取 PIR 运动传感器
- 使用 LDR 测量光线
- 设置光线阈值
- 自动夜灯