ESP8266 Weather Station v1

#include <ESP8266WiFi.h>
#include <time.h>
#include <U8x8lib.h>
#include "DFRobot_BME280.h"
#include "Wire.h"

const char* ssid = "Wifi";              
const char* password = "Password";      

const char* NTP_SERVER = "ch.pool.ntp.org";
const char* TZ_INFO    = "GMT+0BST-1,M3.5.0/01:00:00,M10.5.0/02:00:00";  // enter your time zone (https://remotemonitoringsystems.ca/time-zone-abbreviations.php)

tm timeinfo;
time_t now;
long unsigned lastNTPtime;
unsigned long lastEntryTime;

U8X8_SH1106_128X64_NONAME_SW_I2C u8x8(/* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);   // OLEDs without Reset of the Display

typedef DFRobot_BME280_IIC    BME;    // 
BME   bme(&Wire, 0x77);   // select TwoWire peripheral and set sensor address
#define SEA_LEVEL_PRESSURE    1015.0f

void printLastOperateStatus(BME::eStatus_t eStatus) // show last sensor operate status
{
  switch(eStatus) {
  case BME::eStatusOK:    Serial.println("everything ok"); break;
  case BME::eStatusErr:   Serial.println("unknow error"); break;
  case BME::eStatusErrDeviceNotDetected:    Serial.println("device not detected"); break;
  case BME::eStatusErrParameter:    Serial.println("parameter error"); break;
  default: Serial.println("unknow status"); break;
  }
}

void setup()
{
  u8x8.begin();
  Serial.begin(115200);
  WiFi.begin(ssid, password);

  int counter = 0;
  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(200);    
    if (++counter > 100) 
      ESP.restart();
  }

  configTime(0, 0, NTP_SERVER);
  // See https://github.com/nayarsystems/posix_tz_db/blob/master/zones.csv for Timezone codes for your region
  setenv("GMT0BST,M3.5.0/1,M10.5.0", TZ_INFO, 1);

  if (getNTPtime(10)) 
  {  
    // wait up to 10sec to sync
  } 
  else 
  {
    ESP.restart();
  }
  showTime(&timeinfo);
  lastNTPtime = time(&now);
  lastEntryTime = millis();
    
  bme.reset();
  Serial.println("bme read data test");
  while(bme.begin() != BME::eStatusOK) {
    Serial.println("bme begin faild");
    printLastOperateStatus(bme.lastOperateStatus);
    delay(2000);
  }
  delay(100);
}

void loop()
{
  getNTPtime(10);
  showTime(&timeinfo);
  delay(1000);
  
  float   temp = bme.getTemperature();
  uint32_t    press = bme.getPressure();
  float   alti = bme.calAltitude(SEA_LEVEL_PRESSURE, press);
  float   humi = bme.getHumidity();

  char temp_buff[5]; char hum_buff[5]; char pres_buff[9];
  char cel_buff[11] = "C";
  char per_buff[11] = "%";
  char pa_buff[11] = " Pa";

  dtostrf(temp, 3, 1, temp_buff);
  strcat(temp_buff, cel_buff); 
  dtostrf(humi, 3, 0, hum_buff);
  strcat(hum_buff, per_buff);
  dtostrf(press, 5, 0, pres_buff);
  strcat(pres_buff, pa_buff);
  
  u8x8.setFont(u8x8_font_artossans8_r);
  u8x8.setCursor(0,2);
  u8x8.print("Temp: ");
  u8x8.setCursor(6,2); 
  u8x8.print(temp_buff);
  u8x8.setCursor(0,4);
  u8x8.print("Hum: "); 
  u8x8.setCursor(6,4);
  u8x8.print(hum_buff);
  u8x8.setCursor(0,6);
  u8x8.print("Pres: "); 
  u8x8.setCursor(6,6);
  u8x8.print(pres_buff);
}

bool getNTPtime(int sec) 
{
  {
    uint32_t start = millis();
    do
    {
      time(&now);
      localtime_r(&now, &timeinfo);
      delay(10);
    } while (((millis() - start) <= (1000 * sec)) && (timeinfo.tm_year < (2016 - 1900)));
    
    if (timeinfo.tm_year <= (2016 - 1900)) 
        return false;  // the NTP call was not successful
  }
  return true;
}

void showTime(tm *localTime) 
{
  char time_output[30];
  
  u8x8.setFont(u8x8_font_artossans8_n);
  u8x8.setCursor(0,0);
  sprintf(time_output, "%02d:%02d", localTime->tm_hour, localTime->tm_min);
  u8x8.print(time_output);
  
  u8x8.setFont(u8x8_font_artossans8_r);
  u8x8.setCursor(7,0);
  sprintf(time_output, "%02d/%02d/%02d", localTime->tm_mday, localTime->tm_mon + 1, localTime->tm_year - 100);
  u8x8.print(time_output);
}