计算编码器脉冲
统计快速变化的边沿，避免遗漏
计算编码器脉冲 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。
A Wheel of Pulses
A rotary encoder sends a quick stream of electrical pulses as it spins. Count those pulses and you know how far it has turned.
Too Fast to Poll
Spin an encoder quickly and pulses fly by in microseconds. A normal loop reading the pin would miss many of them.
Interrupts to the Rescue
This is the perfect job for an interrupt. The hardware catches every edge for you, so no pulse slips through unnoticed. ⚡
A Volatile Counter
Make a volatile counter the ISR can increment. Marking it volatile keeps the loop reading the true, up-to-date total.
volatile long pulseCount = 0;Attach the Interrupt
In setup, point attachInterrupt at the encoder pin and fire on RISING so each pulse calls your counting handler.
attachInterrupt(digitalPinToInterrupt(2), countPulse, RISING);A Tiny ISR
The whole handler does one thing: add one to the counter. Short and fast, exactly as a good ISR should be.
void countPulse() {
pulseCount++;
}Read Without Tearing
To copy the count in the loop, briefly pause interrupts so the ISR cannot change it mid-read and leave you a torn value.
noInterrupts();
long c = pulseCount;
interrupts();Use the Count
Now the loop can print the total, compute speed, or react, all while the ISR keeps tallying new pulses in the background.
Serial.println(c);From Pulses to Rotation
Each encoder has a fixed pulses-per-turn. Divide your count by that number to learn how many full revolutions happened.
Measuring Speed
Count pulses over a known time window in the loop, and you can turn that rate into speed or RPM for a motor or wheel.
Reset When Needed
To start a fresh measurement, set the counter back to zero, again pausing interrupts so you do not lose a pulse arriving at that instant.
noInterrupts();
pulseCount = 0;
interrupts();Quick Check
Why do we briefly pause interrupts when reading the pulse counter in the loop?
Recap
You built a pulse counter: a volatile total, a tiny ISR, and safe reads in the loop. Now you can measure rotation and speed reliably. 🎉
常见问题解答
「计算编码器脉冲」课时是免费的吗？
是的 — 「计算编码器脉冲」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。
「计算编码器脉冲」这节课中我会学到什么？
统计快速变化的边沿，避免遗漏 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。
「计算编码器脉冲」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。