How to Set RTC in ES32 using NTP server?

Question

I am working on ESP32 And want to set RTC from the NTP server. How can I get epoch value I have done this thing on CC3200 launchpad and used an NTP server library to obtain epoch value.

Answer 1

this snippet from setup() sets on esp32 the NTP for internal RTC and uses epoch seconds to set time to TimeLib library.

 configTime(gmtOffset_sec, daylightOffset_sec, "pool.ntp.org");
 time_t now = time(nullptr);
 while (now < SECS_YR_2000) {
 delay(100);
 now = time(nullptr);
 }
 setTime(now);

The ESP32 examples library in IDE examples folder has example SimpleTime.

• Duncan C: Is configTime() a blocking function? Seems like it would have to be, seeing as how the Arduino is not a multi-tasking system.
• Juraj: @DuncanC, it is not blocking as you can see on the following while cycle. esp32 core is on esp32 RTOS SDK. arduino is one thread but configTime is a C function from SDK, so the function only activates SNTP