I'm now getting mixed results with some of my code that uses my web page server for testing. Below is some code modified by another to connect to a time server. You might check to see if it will connect more consistantly.
//zoomkat 12-08-11, combined client and server
//simple button GET with iframe code
//for use with IDE 1.0
//open serial monitor and send an g to test client and
//see what the arduino client/server receives
//web page buttons make pin 4 high/low
//use the \ slash to escape the " in the html
//address will look like http://192.168.1.102:84 when submited
//for use with W5100 based ethernet shields
//NTP server implementation added by RobertJP
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
IPAddress ip(192,168,1,102); // ip in lan
IPAddress gateway(192,168,1,1); // internet access via router
IPAddress subnet(255,255,255,0); //subnet mask
IPAddress myserver(208,104,2,86); // zoomkat web page
EthernetServer server(84); //server port
EthernetClient client;
String readString;
//////////////////////NTP declarations
IPAddress timeServer(77,245,91,218); // time.nist.gov NTP server
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
EthernetUDP Udp; // A UDP instance to let us send and receive packets over UDP
unsigned int localPort = 8888; //Port to listen for UDP packets
void setup(){
pinMode(5, OUTPUT); //pin selected to control
Ethernet.begin(mac,ip,gateway,gateway,subnet);
server.begin();
Serial.begin(9600);
Serial.println("server/client 1.0 test 12/08/11"); // keep track of what is loaded
Serial.println("Send an g in serial monitor to test client"); // what to do to test client
Udp.begin(localPort);
Serial.println("UDP started");
}
void loop(){
// check for serial input
if (Serial.available() > 0)
{
byte inChar;
inChar = Serial.read();
if(inChar == 'g')
{
sendGET(); // call sendGET function
}
}
EthernetClient client = server.available();
if (client) {
while (client.connected()) {
if (client.available()) {
char c = client.read();
//read char by char HTTP request
if (readString.length() < 100) {
//store characters to string
readString += c;
//Serial.print(c);
}
//if HTTP request has ended
if (c == '\n') {
///////////////
Serial.println(readString); //print to serial monitor for debuging
//now output HTML data header
if(readString.indexOf('?') >=0) { //don't send new page
client.println("HTTP/1.1 204 Robert");
client.println();
client.println();
}
else {
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
client.println();
client.println("<HTML>");
client.println("<HEAD>");
client.println("<TITLE>Arduino GET test page</TITLE>");
client.println("</HEAD>");
client.println("<BODY>");
client.println("<H1>Zoomkat's simple Arduino 1.0 button</H1>");
client.println("<a href=\"/?on\" target=\"inlineframe\">ON</a>");
client.println("<a href=\"/?off\" target=\"inlineframe\">OFF</a>");
//client.println("<IFRAME name=inlineframe src=\"res://D:/WINDOWS/dnserror.htm\" width=1 height=1\">");
client.println("<IFRAME name=inlineframe style=\"display:none\" >");
client.println("</IFRAME>");
client.println("</BODY>");
client.println("</HTML>");
}
delay(1);
//stopping client
client.stop();
///////////////////// control arduino pin
if(readString.indexOf("on") >0)//checks for on
{
digitalWrite(5, HIGH); // set pin 4 high
Serial.println("Led On");
}
if(readString.indexOf("off") >0)//checks for off
{
digitalWrite(5, LOW); // set pin 4 low
Serial.println("Led Off");
}
//clearing string for next read
readString="";
}
}
}
}
}
void sendGET()
{
Serial.println("Send GET");
sendNTPpacket(timeServer); // send an NTP packet to a time server
// wait to see if a reply is available
delay(1000);
if ( Udp.parsePacket() ) {
Serial.println("Got it!");
// 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(1+(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
}
Serial.println("Done!");
}
// send an NTP request to the time server at the given address
unsigned long sendNTPpacket(IPAddress& address)
{
// 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();
}
