使用 NTP/RTC 获取实时时间
为数据添加准确的日期和时间戳
使用 NTP/RTC 获取实时时间 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。
Why Time Matters
A reading like "24.3 C" is half a story. To make sense of logged data, every sample needs a timestamp telling you exactly when it happened. ⏰
Arduino Has No Clock
Your Arduino forgets the date the moment power drops. It only counts milliseconds since boot, so it has no idea what real-world wall-clock time it is.
Two Ways to Get Time
You can fetch the time from the internet with NTP, or keep it locally with a battery-backed RTC chip. Each fits a different situation.
What NTP Does
NTP (Network Time Protocol) asks a time server online for the current moment. It is accurate and free, but it needs an active WiFi connection to work.
Asking an NTP Server
On an ESP32 one line of setup points your board at a public time server and your timezone offset. Then the board syncs automatically.
configTime(0, 0, "pool.ntp.org");Reading the Synced Time
Once synced, you pull the current time into a struct and read its fields. This gives you year, month, day, hour, and minute to label data.
struct tm now;
getLocalTime(&now);What an RTC Does
An RTC module like the DS3231 keeps ticking on a tiny coin battery, even with the Arduino fully off. No network needed at all.
Wiring an RTC
Most RTC modules talk over I2C, so you connect just four wires: power, ground, SDA, and SCL. That keeps your build wonderfully simple.
Reading from an RTC
With the RTClib library you grab the current moment as a DateTime object, then read its fields just like the NTP version.
DateTime now = rtc.now();
int h = now.hour();NTP or RTC?
Pick NTP when your device is always online and you want zero extra parts. Pick an RTC for offline or battery nodes that still need the right time.
Best of Both
Many strong designs use both: an RTC keeps time offline, and NTP gently corrects its small drift whenever WiFi is available. 🌐
Quick Check
Which time source still works with no internet connection?
Recap
Arduino has no real clock, so add time with NTP online or an RTC offline. Now every reading you log can carry an accurate timestamp. ✅
常见问题解答
「使用 NTP/RTC 获取实时时间」课时是免费的吗？
是的 — 「使用 NTP/RTC 获取实时时间」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。
「使用 NTP/RTC 获取实时时间」这节课中我会学到什么？
为数据添加准确的日期和时间戳 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。
「使用 NTP/RTC 获取实时时间」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
- 使用 NTP/RTC 获取实时时间
- 将 CSV 写入 SD 卡
- 缓冲与批量上传
- 可视化记录的数据