NTP sync first time

[henk1311]

I am using a NTP-server for getting the local time.
After booting my ESP8266 it takes up to 40 seconds before I got an initial NTP reply.
Why is this taking so long and why are the updates sometimes without delay?

Thnx, henk

Sketch fragment:

  configTime(TZ_INFO, NTP_SERVER);
  uint32_t startTime = millis();

  Serial.print("wait for first valid timestamp ");
  while (time(nullptr) < 100000ul) {
    Serial.printf(".");
    delay(100);
  }
  uint32_t runtimeMillis = millis() - startTime;
  Serial.printf("\ntime synced in %d ms.\n", runtimeMillis);

[d-a-v]

You can

• use Netdump to understand what's hapenning within these 40secs
• force SNTP to start with sntp_init() after configTime() (but after you get an IP address)

[henk1311]

Thnx for your fast answer: sntp_init() didn't help.

Yesterday I found a solution:
Forcing the sntp_startup_delay to zero was strangely not the solution, but reducing sntp_update_delay to 15 seconds (RFC minimum) was.
After the first ntp response I set this value back to the default value (1 hour):

Sketch change:
uint32_t sntp_update_delay_MS_rfc_not_less_than_15000 ()
{
// //info_sntp_update_delay_MS_rfc_not_less_than_15000_has_been_called = true;
if (FirstDNS) {
FirstDNS = false;
return 15000; // min = 15000 = 15s
} else
return 3600000; // 1 hour
}

gr henk

[adam-ah]

The simplest way to force an immediate update would be to call

    sntp_stop();
    sntp_init();

after you get the IP from Wifi. A simple init doesn't do the trick.

[henk1311]

Hi Adam, I tried your suggestion but it didn’t help. I still have to wait ca 30s for the first NTP sync. Gr henk My sketch: #include <ESP8266WiFi.h> #include <time.h> #include <sntp.h> … void setup() { Serial.begin(115200); Serial.println("\n----------------------"); Serial.println("Booting ESP8266"); WiFi.mode(WIFI_STA); WiFi.setSleepMode(WIFI_NONE_SLEEP); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) yield(); Serial.print("WiFi address:"); Serial.println(WiFi.localIP()); Serial.print("Host:"); Serial.println(host); configTime(TZ_INFO, NTP_SERVER); uint32_t startTime = millis(); // does not help... sntp_stop(); sntp_init(); Serial.print("wait for first valid timestamp "); while (time(nullptr) < 100000ul) { Serial.printf("."); delay(500); } uint32_t runtimeMillis = millis() - startTime; Serial.printf("\ntime synced in %d ms.\n", runtimeMillis); // takes 0-30 seconds !!!! Don't know why it takes so long to sync. } Van: Adam H ***@***.***> Verzonden: dinsdag 31 augustus 2021 11:38 Aan: esp8266/Arduino ***@***.***> CC: henk1311 ***@***.***>; Author ***@***.***> Onderwerp: Re: [esp8266/Arduino] NTP sync first time (#8032) The simplest way to force an immediate update would be to call sntp_stop(); sntp_init(); after you get the IP from Wifi. A simple init doesn't do the trick. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#8032 (reply in thread)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/AUCSIMZBKWWMT5VAPYZKPCLT7SPG7ANCNFSM445UIK5Q> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> . <https://github.com/notifications/beacon/AUCSIM5L3NAY3WZJQTNON53T7SPG7A5CNFSM445UIK52YY3PNVWWK3TUL52HS4DFWFCGS43DOVZXG2LPNZBW63LNMVXHJKTDN5WW2ZLOORPWSZGOAAJTI3Q.gif>

[adam-ah]

That's interesting. I just tried your code, with trivial modifications like adding my password, and that's the output:

18:40:22.468 -> Booting ESP8266
18:40:30.000 -> WiFi address:192.168.0.108
18:40:30.000 -> wait for first valid timestamp .
18:40:30.499 -> time synced in 500 ms.
....
18:45:35.658 -> Booting ESP8266
18:45:40.230 -> WiFi address:192.168.0.108
18:45:40.230 -> wait for first valid timestamp .............................................................
18:46:10.757 -> time synced in 30507 ms.

It looks like sometimes instant (500ms) sometimes 30s.

My code looked marginally different from yours and once I added those changes to your code I could not reproduce the problem; however, it does not mean it solves it, but maybe reduced it?

The changes I made:

while (WiFi.status() != WL_CONNECTED)
  // yield();
  delay(100);

// configTime(TZ_INFO, NTP_SERVER);
configTime(0, 0, NTP_SERVER);
setenv("TZ", TZ_INFO, 1);
tzset();

[Pablo2048]

Please pay attention to message format, otherwise it's an hardly readable mess :-( . You can try:

    sntp_stop();
    configTime(timeZone.c_str(), ntpServer.c_str());
    sntp_init();

[henk1311]

Hi Pablo.  This is the trick.Now I get an immediate NTP respons.Thanks a lot.Gr Henk      Verzonden vanaf mijn Galaxy -------- Oorspronkelijk bericht --------Van: Pablo2048 ***@***.***> Datum: 04-09-2021 10:40 (GMT+01:00) Aan: esp8266/Arduino ***@***.***> Cc: henk1311 ***@***.***>, Author ***@***.***> Onderwerp: Re: [esp8266/Arduino] NTP sync first time (#8032) Please pay attention to message format, otherwise it's an hardly readable mess :-( . You can try: sntp_stop(); configTime(timeZone.c_str(), ntpServer.c_str()); sntp_init(); —You are receiving this because you authored the thread.Reply to this email directly, view it on GitHub, or unsubscribe.Triage notifications on the go with GitHub Mobile for iOS or Android.