How to send data every hour to Database using ESP8266?

Question

I would like to send hourly data to a database with my ESP8266. However, I don't know how to send the data exactly every hour. I don't want to use delay(). Can someone help me?

Answer 1

this is a skeleton of a sketch for retrieving time from Internet with the esp8266 into the internal RTC, set the time into the TimeLib and use TimeLib's minute() function to execute something at hh:00.

#include <ESP8266WiFi.h>
#include <TimeLib.h>
#include <sntp.h>
#include <TZ.h>

#define TIME_ZONE TZ_Europe_London

bool doneSending = false; // flag to send only once in the first minute of the hour

void setup() {

  WiFi.begin(ssid, pass);

  configTime(TIME_ZONE, "pool.ntp.org");
  time_t now = time(nullptr);
  while (now < SECS_YR_2000) { // why until time is retrieve from Internet
    delay(100);
    now = time(nullptr);
  }
  setTime(now); // set the time into TimeLib
}

void loop() {
  if (minute() == 0) { // it is hh:00
    if (!doneSending) {
      sendData();
      doneSending= true;
    }
  } else if (doneSending) {
    doneSending = false; // reset after the :00 minute is over
  }
}