Using the new Arduino IDE for ESP8266 and found bugs, report them here

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User avatar
By kolalde
#35529 Hi,

I'm using:
Examples/ESP8266Wifi/NTPClient.ino
ESP8266/Arduino version 1.6.5-1160-gef26c5f
Arduino IDE 1.6.5

As supplied, once I update the ssid/pwd, the sample runs well. Minutes on end (many more than 5).
If I update the delay interval at the bottom of the loop() function (line 127):

delay(10000);
to
delay(1000 * 60 * 5); // wait 5 minutes

the sample fails to collect an NTP response after the first successful attempt. Line 80 catches an error, but I've not narrowed down which call is actually having issue. Originally I was seeing this problem in a much bigger sketch. There I was setting a sync interval (setSyncInterval) to 5 minutes and seeing a similar response failure. I went back to the sample to reproduce.

Anyone else seeing this? Hoping I've missed something obvious. If not, I'll continue to narrow.

Thanks,
ko
Last edited by kolalde on Fri Dec 04, 2015 6:32 am, edited 1 time in total.
User avatar
By kolalde
#35592 Thanks for the reply.

Yeah, I was suspect on the use of delay() as well, but I thought it managed the need to yield on it's own. FWIW, in a different test I've got another sketch that doesn't use delay. Actually two tests, one that was using setSyncInterval to drive the NTP code, and other that keeps track of time via use of millis() and a counter. All tests show similar results.

What connection are you thinking might be lost? The Wifi? In one of the tests I use (WiFi.status() == WL_CONNECTED) in every loop() pass. I don't see a disconnect (if that's a good way to determine disconnect).

After a bit more playing I'm seeing Wifi.hostByName return a valid IP for time.dist.gov during the first successful pass. On the next pass, 5 minutes later, hostByName returns 0.0.0.0. And it continues to return 0.0.0.0 every 5 minutes. This obviously makes the NTP code fail.

HOWEVER at 20 minute intervals a valid IP is returned by hostByName and the NTP packet is sent and response received successfully. This seems pretty consistent.

So what I think I know:
- NTPClient example works as provided
- increase the loop delay() interval from 10 seconds to 5 minutes causes a hostByName failure on the second pass. Subsequent passes also fail (every 5 minutes) but passes at the 20 minute boundaries work.
- doesn't seem to be related to delay(), as shown in other tests

More testing later.

Thanks,
ko
User avatar
By kolalde
#35593 One more quick test before I have to go out.

Removed the hostByName call and replaced with hardcoded IPAddress.

This was the result. NTP failure until 20 minutes goes by. Either a well coordinated internet provider blocking of things NTP, or some network stack issue???

Code: Select all..........
WiFi connected
IP address:
192.168.1.24
Starting UDP
Local port: 2390

128.138.141.172
sending NTP packet...
packet received, length=48
Seconds since Jan 1 1900 = 3658156222
Unix time = 1449167422
The UTC time is 18:30:22             <<<<<<<<   First pass succeeds.

128.138.141.172
sending NTP packet...
no packet yet                            <<<<<<<<   5 minutes later

128.138.141.172
sending NTP packet...
no packet yet                            <<<<<<<<   10 minutes later

128.138.141.172
sending NTP packet...
no packet yet                            <<<<<<<<   15 minutes later

128.138.141.172
sending NTP packet...
packet received, length=48
Seconds since Jan 1 1900 = 3658157426
Unix time = 1449168626
The UTC time is 18:50:26             <<<<<<<<   20 minutes later, this pass succeeds.


I added the comments above. Here's the example with a line or two change to show the error.

Code: Select all/*

 Udp NTP Client

 Get the time from a Network Time Protocol (NTP) time server
 Demonstrates use of UDP sendPacket and ReceivePacket
 For more on NTP time servers and the messages needed to communicate with them,
 see http://en.wikipedia.org/wiki/Network_Time_Protocol

 created 4 Sep 2010
 by Michael Margolis
 modified 9 Apr 2012
 by Tom Igoe
 updated for the ESP8266 12 Apr 2015
 by Ivan Grokhotkov

 This code is in the public domain.

 */

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

char ssid[] = "...";  //  your network SSID (name)
char pass[] = "...";       // your network password


unsigned int localPort = 2390;      // local port to listen for UDP packets

/* Don't hardwire the IP address or we won't get the benefits of the pool.
 *  Lookup the IP address for the host name instead */
//IPAddress timeServer(129, 6, 15, 28); // time.nist.gov NTP server
//IPAddress timeServerIP; // time.nist.gov NTP server address
IPAddress timeServerIP(128,138,141,172);
const char* ntpServerName = "time.nist.gov";

const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message

byte packetBuffer[ NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets

// A UDP instance to let us send and receive packets over UDP
WiFiUDP udp;

void setup()
{
  Serial.begin(115200);
  Serial.println();
  Serial.println();

  // We start by connecting to a WiFi network
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, pass);
 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
 
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  Serial.println("Starting UDP");
  udp.begin(localPort);
  Serial.print("Local port: ");
  Serial.println(udp.localPort());
}

void loop()
{
  //get a random server from the pool
//  WiFi.hostByName(ntpServerName, timeServerIP);
  Serial.println(timeServerIP.toString());

  sendNTPpacket(timeServerIP); // send an NTP packet to a time server
  // wait to see if a reply is available
  delay(1000);
 
  int cb = udp.parsePacket();
  if (!cb) {
    Serial.println("no packet yet");
  }
  else {
    Serial.print("packet received, length=");
    Serial.println(cb);
    // We've received a packet, read the data from it
    udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer

    //the timestamp starts at byte 40 of the received packet and is four bytes,
    // or two words, long. First, esxtract the two words:

    unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
    unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
    // combine the four bytes (two words) into a long integer
    // this is NTP time (seconds since Jan 1 1900):
    unsigned long secsSince1900 = highWord << 16 | lowWord;
    Serial.print("Seconds since Jan 1 1900 = " );
    Serial.println(secsSince1900);

    // now convert NTP time into everyday time:
    Serial.print("Unix time = ");
    // Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
    const unsigned long seventyYears = 2208988800UL;
    // subtract seventy years:
    unsigned long epoch = secsSince1900 - seventyYears;
    // print Unix time:
    Serial.println(epoch);


    // print the hour, minute and second:
    Serial.print("The UTC time is ");       // UTC is the time at Greenwich Meridian (GMT)
    Serial.print((epoch  % 86400L) / 3600); // print the hour (86400 equals secs per day)
    Serial.print(':');
    if ( ((epoch % 3600) / 60) < 10 ) {
      // In the first 10 minutes of each hour, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.print((epoch  % 3600) / 60); // print the minute (3600 equals secs per minute)
    Serial.print(':');
    if ( (epoch % 60) < 10 ) {
      // In the first 10 seconds of each minute, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.println(epoch % 60); // print the second
  }
  // wait ten seconds before asking for the time again
  delay(10000*6*5);
}

// send an NTP request to the time server at the given address
unsigned long sendNTPpacket(IPAddress& address)
{
  Serial.println("sending NTP packet...");
  // set all bytes in the buffer to 0
  memset(packetBuffer, 0, NTP_PACKET_SIZE);
  // Initialize values needed to form NTP request
  // (see URL above for details on the packets)
  packetBuffer[0] = 0b11100011;   // LI, Version, Mode
  packetBuffer[1] = 0;     // Stratum, or type of clock
  packetBuffer[2] = 6;     // Polling Interval
  packetBuffer[3] = 0xEC;  // Peer Clock Precision
  // 8 bytes of zero for Root Delay & Root Dispersion
  packetBuffer[12]  = 49;
  packetBuffer[13]  = 0x4E;
  packetBuffer[14]  = 49;
  packetBuffer[15]  = 52;

  // all NTP fields have been given values, now
  // you can send a packet requesting a timestamp:
  udp.beginPacket(address, 123); //NTP requests are to port 123
  udp.write(packetBuffer, NTP_PACKET_SIZE);
  udp.endPacket();
}