esp8266如何获取形如2019-03-05 015312的时间

ESP8266可以通过以下步骤获取形如“2019-03-05 01:53:12”的时间：

连接到Wi-Fi网络并获取当前时间。可以使用NTP协议来获取网络时间，也可以使用自己的服务器或其他时间源。
将获取到的时间转换成字符串。可以使用strftime函数将时间格式化为需要的字符串格式。
将字符串转换成时间结构体。可以使用strptime函数将字符串转换成tm结构体。
可以使用tm结构体的成员变量来获取需要的时间信息，如年、月、日、小时、分钟、秒等。

示例代码如下：

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

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

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

WiFiUDP Udp;
unsigned int localPort = 8888;

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(localPort);
  Serial.println("UDP started");

  setSyncProvider(getNtpTime);
  setSyncInterval(300);
}

void loop() {
  time_t now = time(nullptr);
  char timeStr[20];
  strftime(timeStr, sizeof(timeStr), "%Y-%m-%d %H:%M:%S", localtime(&now));
  Serial.println(timeStr);

  delay(1000);
}

time_t getNtpTime() {
  IPAddress ntpServerIP;
  while (Udp.parsePacket() > 0); // discard any previously received packets
  Serial.println("Transmit NTP Request");
  WiFi.hostByName(ntpServerName, ntpServerIP);
  sendNTPPacket(ntpServerIP);
  uint32_t beginWait = millis();
  while (millis() - beginWait < 1500) {
    int size = Udp.parsePacket();
    if (size >= NTP_PACKET_SIZE) {
      Serial.println("Receive NTP Response");
      byte packetBuffer[NTP_PACKET_SIZE];
      Udp.read(packetBuffer, NTP_PACKET_SIZE);
      unsigned long secsSince1900 = (unsigned long)packetBuffer[40] << 24 |
        (unsigned long)packetBuffer[41] << 16 |
        (unsigned long)packetBuffer[42] << 8 |
        (unsigned long)packetBuffer[43];
      return secsSince1900 - 2208988800UL + timeZone * SECS_PER_HOUR;
    }
    delay(10);
  }
  Serial.println("No NTP Response :-(");
  return 0;
}

void sendNTPPacket(IPAddress& address) {
  byte packetBuffer[NTP_PACKET_SIZE];
  memset(packetBuffer, 0, NTP_PACKET_SIZE);
  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
  packetBuffer[12] = 49;
  packetBuffer[13] = 0x4E;
  packetBuffer[14] = 49;
  packetBuffer[15] = 52;
  Udp.beginPacket(address, 123);
  Udp.write(packetBuffer, NTP_PACKET_SIZE);
  Udp.endPacket();
}

注意：以上代码使用了NTP协议来获取网络时间，需要连接到Wi-Fi网络，并且需要访问外部时间服务器。如果使用自己的服务器或其他时间源，请相应修改代码。