自动夜灯
天黑且检测到移动时点亮 LED
自动夜灯 是 CoddyKit 上的免费 Arduino & IoT Academy 课时。 这是第 4 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。
The Project Goal
Now combine your skills into one device: an automatic night light that switches an LED on when it is dark and someone moves.
Two Inputs, One Output
You will read two inputs, the LDR for light and the PIR for motion, then drive one output: an LED.
Plan the Pins
Assign each part a pin: the LDR on an analog input, the PIR on a digital input, and the LED on a digital output.
Set Up the LED
In setup, mark the LED pin as an OUTPUT so the board can drive current to it on command.
pinMode(ledPin, OUTPUT);Read Both Sensors
Each loop, grab a fresh light value and the current motion state so your decision uses up-to-date data.
int light = analogRead(A0);
int motion = digitalRead(pirPin);Combine With AND
The light should turn on only when it is dark and motion is present. Use && to require both at once.
if (light < threshold && motion == HIGH)Turn the LED On
When both conditions hold, drive the LED pin HIGH to light it up for whoever just walked in.
digitalWrite(ledPin, HIGH);Turn the LED Off
Otherwise, set the pin LOW so the light goes dark again when motion stops or the room is bright.
digitalWrite(ledPin, LOW);Keep It Lit Briefly
People dislike a light that snaps off instantly. Add a short hold time so it stays on a while after the last motion.
Skip Daytime Triggers
The light check matters: requiring dark means daytime motion is ignored, saving power and avoiding pointless blinks.
Make It Real
Swap the LED for a relay and you can switch a real lamp. Same logic, bigger impact in your hallway.
Quick Check
What condition turns the night light on?
Recap: Your Night Light
You merged an LDR, a PIR, and an LED, using a threshold and && so the light glows only in the dark with motion.
常见问题解答
「自动夜灯」课时是免费的吗？
是的 — 「自动夜灯」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。
「自动夜灯」这节课中我会学到什么？
天黑且检测到移动时点亮 LED 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 4 节课，共 4 节。
「自动夜灯」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。