esp8266获取时间的简单方法

可以使用NTP协议获取当前的时间。以下是使用Arduino IDE编写的ESP8266获取时间的示例代码：

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

WiFiUDP udp;

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

const char* ntpServerName = "pool.ntp.org";
const int timeZone = 8;

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  udp.begin(123);
  Serial.println("UDP started");

  setSyncInterval(300);
  setSyncProvider(getNtpTime);
}

void loop() {
  time_t now = time(nullptr);
  if (now > 0) {
    Serial.println(ctime(&now));
  }
  delay(1000);
}

time_t getNtpTime() {
  IPAddress ntpServerIP;
  WiFi.hostByName(ntpServerName, ntpServerIP);
  Serial.print("NTP server IP address: ");
  Serial.println(ntpServerIP);

  byte packetBuffer[48];
  memset(packetBuffer, 0, 48);
  packetBuffer[0] = 0b11100011;
  packetBuffer[1] = 0;
  packetBuffer[2] = 6;
  packetBuffer[3] = 0xEC;
  packetBuffer[12] = 49;
  packetBuffer[13] = 0x4E;
  packetBuffer[14] = 49;
  packetBuffer[15] = 52;

  udp.beginPacket(ntpServerIP, 123);
  udp.write(packetBuffer, 48);
  udp.endPacket();

  delay(1000);

  int packetSize = udp.parsePacket();
  if (packetSize == 0) {
    Serial.println("No NTP packet received");
    return 0;
  }

  udp.read(packetBuffer, 48);

  unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
  unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
  unsigned long secsSince1900 = highWord << 16 | lowWord;

  const unsigned long seventyYears = 2208988800UL;
  unsigned long epoch = secsSince1900 - seventyYears;

  Serial.print("NTP time: ");
  Serial.println(epoch);

  return epoch + timeZone * 3600;
}

这个示例代码将ESP8266连接到Wi-Fi网络，并使用NTP协议从ntpServerName变量指定的NTP服务器获取当前时间。获取时间的函数是`getNtpTime()`，它会返回从1970年1月1日0时0分0秒到现在的秒数。在`setup()`函数中，我们设置了时间同步间隔为300秒，并将`getNtpTime()`函数设置为时间同步提供程序。在`loop()`函数中，我们使用`time()`函数获取当前时间，并使用`ctime()`函数将其格式化为可读的字符串。