ESP32 seconds from epoch

Question

When using ESP8266 - getting seconds from epoch is done using

NTP.begin(NTPserver, 2, true);
delay(delay_tries);
time_t t = now();

while t stores amount of seconds from 1-1-1970.

When trying to do the same, using ESP32 - I cant get that numeric representation.

code below is from ESP32 example- updating time using NTP server ( process is done correct ). BUT when using now() yields 1970, as if NTP update has never occured.

How can I get time from Epoch ?

#include <WiFi.h>
#include "time.h"
#include <TimeLib.h> <------- Added to original Code
const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASS";
const char* ntpServer = "pool.ntp.org";
const long gmtOffset_sec = 3600;
const int daylightOffset_sec = 3600;
void printLocalTime()
{
 struct tm timeinfo;
 if(!getLocalTime(&timeinfo)){
 Serial.println("Failed to obtain time");
 return;
 }
 Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
}
void setup()
{
 Serial.begin(115200);
 //connect to WiFi
 Serial.printf("Connecting to %s ", ssid);
 WiFi.begin(ssid, password);
 while (WiFi.status() != WL_CONNECTED) {
 delay(500);
 Serial.print(".");
 }
 Serial.println(" CONNECTED");
 //init and get the time
 configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);
 printLocalTime();
 //disconnect WiFi as it's no longer needed
 WiFi.disconnect(true);
 WiFi.mode(WIFI_OFF);
}
void loop()
{
 delay(1000);
 printLocalTime();
 Serial.println(now()); <-------- Added to original code
}

• Jaromanda X: where is now() defined or even used in the code you posted?
• Jaromanda X: Does your code output "Failed to obtain time"?
• Jaromanda X: try time(nullptr) instead of now() - since now() is not even a valid function in the code you posted
• Juraj: you can use the NTP library on ESP32 and you can use the SDK time functions on esp8266 too
• Jaromanda X: @Guy.D - just because you added now() to the code you've shown, doesn't make it valid (if I try to use now() in ESP32 code, it doesn't even compile :p

Answer 1

to return 'epoch' seconds there is a function time in time.h

time_t now;
time(&now);

time_t is defined as long

this time is retrieved by the ESP32 SDK from NTP servers configured with ESP32 Arduino function configTime

EDIT: it is the standard C time() function

• Jaromanda X: since time also returns a time_t you can use it like now() ... i.e. time(nullptr);