编写程序使用esp8266获取时间

可以使用ESP8266连接到NTP服务器获取时间。以下是一些基本的代码示例：

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

// Replace with your network credentials
const char* ssid     = "your_SSID";
const char* password = "your_PASSWORD";

// Define NTP Servers:
IPAddress timeServerIP; // NTP server IP address
const char* ntpServerName = "pool.ntp.org";

// NTP time stamp is in the first 48 bytes of the message
const int NTP_PACKET_SIZE = 48;
byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets

// A UDP instance to let us send and receive packets over UDP
WiFiUDP udp;

void setup() {
  Serial.begin(115200);
  delay(1000);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Set NTP server IP address
  WiFi.hostByName(ntpServerName, timeServerIP);
}

void loop() {
  // Send an NTP request to the time server
  sendNTPpacket(timeServerIP);
 
  // Wait for response
  delay(1000);
 
  int cb = udp.parsePacket();
  if (!cb) {
    Serial.println("No packet yet");
  }
  else {
    Serial.print("Packet received, length=");
    Serial.println(cb);
 
    // We've received a packet, read the data from it
    udp.read(packetBuffer, NTP_PACKET_SIZE);
 
    // The timestamp starts at byte 40 of the received packet and is four bytes,
    // or two words, long. First, extract the two words:
    unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
    unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
    // Combine the four bytes (two words) into a long integer
    unsigned long secsSince1900 = highWord << 16 | lowWord;
 
    // Subtract seventy years (1970-1900) to get Unix time
    const unsigned long seventyYears = 2208988800UL;
    unsigned long epoch = secsSince1900 - seventyYears;
 
    // Print the Unix time:
    Serial.print("Unix time = ");
    Serial.println(epoch);
  }
}

// Send an NTP request to the time server at the given address
void sendNTPpacket(IPAddress& address) {
  // Set all bytes in the buffer to 0
  memset(packetBuffer, 0, NTP_PACKET_SIZE);
  // Initialize values needed to form NTP request
  packetBuffer[0] = 0b11100011;   // LI, Version, Mode
  packetBuffer[1] = 0;     // Stratum, or type of clock
  packetBuffer[2] = 6;     // Polling Interval
  packetBuffer[3] = 0xEC;  // Peer Clock Precision
  // 8 bytes of zero for Root Delay & Root Dispersion
  packetBuffer[12]  = 49;
  packetBuffer[13]  = 0x4E;
  packetBuffer[14]  = 49;
  packetBuffer[15]  = 52;
  // Send NTP request
  udp.beginPacket(address, 123); //NTP requests are to port 123
  udp.write(packetBuffer, NTP_PACKET_SIZE);
  udp.endPacket();
}

这段代码会连接到Wi-Fi网络，然后从NTP服务器获取当前时间并将其显示在串口终端上。你需要替换代码中的Wi-Fi凭证和NTP服务器名称以适应你的环境。