Use WiFi.hostByName to resolve IP

This commit is contained in:
Mike Causer
2016-03-21 13:14:32 +11:00
parent 0bfe218b56
commit d66874d5d8

View File

@@ -1,5 +1,5 @@
/*
* Time_NTP.pde
* TimeNTP_ESP8266WiFi.ino
* Example showing time sync to NTP time source
*
* This sketch uses the ESP8266WiFi library
@@ -13,10 +13,11 @@ const char ssid[] = "*************"; // your network SSID (name)
const char pass[] = "********"; // your network password
// NTP Servers:
IPAddress timeServer(132, 163, 4, 101); // time-a.timefreq.bldrdoc.gov
// IPAddress timeServer(132, 163, 4, 102); // time-b.timefreq.bldrdoc.gov
// IPAddress timeServer(132, 163, 4, 103); // time-c.timefreq.bldrdoc.gov
static const char ntpServerName[] = "us.pool.ntp.org";
//static const char ntpServerName[] = "time.nist.gov";
//static const char ntpServerName[] = "time-a.timefreq.bldrdoc.gov";
//static const char ntpServerName[] = "time-b.timefreq.bldrdoc.gov";
//static const char ntpServerName[] = "time-c.timefreq.bldrdoc.gov";
const int timeZone = 1; // Central European Time
//const int timeZone = -5; // Eastern Standard Time (USA)
@@ -48,7 +49,6 @@ void setup()
Serial.print(".");
}
Serial.print("IP number assigned by DHCP is ");
Serial.println(WiFi.localIP());
Serial.println("Starting UDP");
@@ -57,6 +57,7 @@ void setup()
Serial.println(Udp.localPort());
Serial.println("waiting for sync");
setSyncProvider(getNtpTime);
setSyncInterval(300);
}
time_t prevDisplay = 0; // when the digital clock was displayed
@@ -71,7 +72,8 @@ void loop()
}
}
void digitalClockDisplay(){
void digitalClockDisplay()
{
// digital clock display of the time
Serial.print(hour());
printDigits(minute());
@@ -85,12 +87,11 @@ void digitalClockDisplay(){
Serial.println();
}
void printDigits(int digits){
void printDigits(int digits)
{
// utility for digital clock display: prints preceding colon and leading 0
Serial.print(":");
if(digits < 10)
if (digits < 10)
Serial.print('0');
Serial.print(digits);
}
@@ -102,9 +103,16 @@ byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming & outgoing packets
time_t getNtpTime()
{
IPAddress ntpServerIP; // NTP server's ip address
while (Udp.parsePacket() > 0) ; // discard any previously received packets
Serial.println("Transmit NTP Request");
sendNTPpacket(timeServer);
// get a random server from the pool
WiFi.hostByName(ntpServerName, ntpServerIP);
Serial.print(ntpServerName);
Serial.print(": ");
Serial.println(ntpServerIP);
sendNTPpacket(ntpServerIP);
uint32_t beginWait = millis();
while (millis() - beginWait < 1500) {
int size = Udp.parsePacket();