oled显示网络时间, wifi链接网络

// ntp_get_date.h
#include "time.h"

String week[8] = {
  "Sun", "Mon", "Tues", "Wednes", "Thur", "Fri", "Sat"
};

void printLocalTime(Adafruit_SSD1306 &display) { //打印本地时间函数
  struct tm timeinfo;
  if(!getLocalTime( & timeinfo)) {
    Serial.println("Failed to obtain time");
    return;
  }
  Serial.println(&timeinfo, "%A, %Y-%m-%d %H:%M:%S");
  char display_str[30] = {0};
  sprintf(display_str,"%04d-%02d-%02d %02d:%02d:%02d %01d", 
    timeinfo.tm_year+1900, 
    timeinfo.tm_mon+1, 
    timeinfo.tm_mday, 
    timeinfo.tm_hour, 
    timeinfo.tm_min, 
    timeinfo.tm_sec, timeinfo.tm_wday);
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println(display_str);
  display.display();
}

const char * ntpServer = "pool.ntp.org";
const long gmtOffset_sec = 28800;
const int daylightOffset_sec = 0;

void ntp_get_date_init() {
  // 将请求数据包传输到NTP服务器，并将接收到的时间戳数据包解析为可读格式
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);
}

// main.cpp
#include <Arduino.h>
#include <WiFi.h>
#include <Adafruit_SSD1306.h>
#include "ntp_get_date.h"
Adafruit_SSD1306 display = Adafruit_SSD1306(128, 32, &Wire);

const char* id="Wifi账号";   //定义两个字符串指针常量
const char* psw="wifi密码";

void setup() {
  // 串口初始化
  Serial.begin(115200);
  // oled初始化
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
    Serial.println(F("SSD1306 allocation failed"));
    for (;;)
      ; // Don't proceed, loop forever
  }
  display.display();
  delay(500); 
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setRotation(0);
  display.clearDisplay();
  // wifi初始化
  WiFi.begin(id,psw);
  while(WiFi.status()!=WL_CONNECTED){			//未连接上
    delay(500);
    Serial.println("connection...");
  }
  display.setCursor(0, 0);
  display.println("wifi connect to Wifi007 success");
  display.display();
  Serial.println("wifi connect to Wifi007 success");

  ntp_get_date_init();
}


void loop() {
  printLocalTime(display);
  delay(500);
}