I was trying to have an arduino uno with an Ethernet shield, get information from the national weather service web site and then post it on a web site from the same arduino.
So...
Get info from web ------ post that info along with other info TO web (ardunio being the web server).
Sorry I'm not very savvy when it comes to the correct terms about web servers, clients, etc...
I can get each of the components to work, meaning I can get the information from the web in one code and in a seperate code post my information. But when I combine the codes, nothing really works.
I don't know how to combine the codes (or if it is even possible!).
Here are the two codes. I used examples and lightly modified them.
Thanks for any insight or help in advance.
//////////////////////////////////////////////
// Get XML formatted data from the web.
// 1/6/08 Bob S. - Created
//
// Assumptions: single XML line looks like:
// <tag>data</tag> or <tag>data
//
// Get current weather observation for Raleigh from weather.gov in XML format
//
//////////////////////////////////////////////
// Include description files for other libraries used (if any)
#include <string.h>
#include <Ethernet.h>
#include <SPI.h>
// Define Constants
// Max string length may have to be adjusted depending on data to be extracted
#define MAX_STRING_LEN 20
// Setup vars
char tagStr[MAX_STRING_LEN] = "";
char dataStr[MAX_STRING_LEN] = "";
char tmpStr[MAX_STRING_LEN] = "";
char endTag[3] = {'<', '/', '\0'};
int len;
// Flags to differentiate XML tags from document elements (ie. data)
boolean tagFlag = false;
boolean dataFlag = false;
// Ethernet vars
byte mac[] = { 0x90, 0xA2, 0xDA, 0x00, 0xE3, 0xCA };
byte ip[] = { 000, 000, 0, 000 };
byte gateway[] = { 000, 000, 0, 0 };
byte server[] = { 140, 90, 113, 200 }; // www.weather.gov
// Start ethernet client
Client client(server, 80);
void setup()
{
Serial.begin(9600);
Serial.println("Starting WebWx");
Serial.println("connecting...");
Ethernet.begin(mac, ip);
delay(1000);
if (client.connect()) {
Serial.println("connected");
client.println("GET /xml/current_obs/KMMK.xml HTTP/1.0");
client.println();
delay(2000);
} else {
Serial.println("connection failed");
}
}
void loop() {
// Read serial data in from web:
while (client.available()) {
serialEvent();
}
if (!client.connected()) {
//Serial.println();
//Serial.println("Disconnected");
client.stop();
// Time until next update
//Serial.println("Waiting");
// for (int t = 1; t <= 15; t++) {
// delay(10000); // 1 minute
// }
if (client.connect()) {
//Serial.println("Reconnected");
client.println("GET /xml/current_obs/KMMK.xml HTTP/1.0");
client.println();
delay(2000);
} else {
Serial.println("Reconnect failed");
}
}
}
// Process each char from web
void serialEvent() {
// Read a char
char inChar = client.read();
//Serial.print(".");
if (inChar == '<') {
addChar(inChar, tmpStr);
tagFlag = true;
dataFlag = false;
} else if (inChar == '>') {
addChar(inChar, tmpStr);
if (tagFlag) {
strncpy(tagStr, tmpStr, strlen(tmpStr)+1);
}
// Clear tmp
clearStr(tmpStr);
tagFlag = false;
dataFlag = true;
} else if (inChar != 10) {
if (tagFlag) {
// Add tag char to string
addChar(inChar, tmpStr);
// Check for </XML> end tag, ignore it
if ( tagFlag && strcmp(tmpStr, endTag) == 0 ) {
clearStr(tmpStr);
tagFlag = false;
dataFlag = false;
}
}
if (dataFlag) {
// Add data char to string
addChar(inChar, dataStr);
}
}
// If a LF, process the line
if (inChar == 10 ) {
/*
Serial.print("tagStr: ");
Serial.println(tagStr);
Serial.print("dataStr: ");
Serial.println(dataStr);
*/
// Find specific tags and print data
if (matchTag("<temp_f>")) {
Serial.print("Temp: ");
Serial.print(dataStr);
}
if (matchTag("<relative_humidity>")) {
Serial.print(", Humidity: ");
Serial.print(dataStr);
}
if (matchTag("<pressure_in>")) {
Serial.print(", Pressure: ");
Serial.print(dataStr);
Serial.println("");
}
// Clear all strings
clearStr(tmpStr);
clearStr(tagStr);
clearStr(dataStr);
// Clear Flags
tagFlag = false;
dataFlag = false;
}
}
/////////////////////
// Other Functions //
/////////////////////
// Function to clear a string
void clearStr (char* str) {
int len = strlen(str);
for (int c = 0; c < len; c++) {
str[c] = 0;
}
}
//Function to add a char to a string and check its length
void addChar (char ch, char* str) {
char *tagMsg = "<TRUNCATED_TAG>";
char *dataMsg = "-TRUNCATED_DATA-";
// Check the max size of the string to make sure it doesn't grow too
// big. If string is beyond MAX_STRING_LEN assume it is unimportant
// and replace it with a warning message.
if (strlen(str) > MAX_STRING_LEN - 2) {
if (tagFlag) {
clearStr(tagStr);
strcpy(tagStr,tagMsg);
}
if (dataFlag) {
clearStr(dataStr);
strcpy(dataStr,dataMsg);
}
// Clear the temp buffer and flags to stop current processing
clearStr(tmpStr);
tagFlag = false;
dataFlag = false;
} else {
// Add char to string
str[strlen(str)] = ch;
}
}
// Function to check the current tag for a specific string
boolean matchTag (char* searchTag) {
if ( strcmp(tagStr, searchTag) == 0 ) {
return true;
} else {
return false;
}
}