Diff: main.cpp

Revision:

0:537d849c3d8c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Apr 21 03:45:58 2012 +0000
@@ -0,0 +1,84 @@
+#include "mbed.h"
+#include "EthernetNetIf.h"
+#include "HTTPClient.h"
+#include "spdomparser.hpp"
+#include "spxmlnode.hpp"
+#include "spxmlhandle.hpp"
+#include "TextLCD.h"
+// Internet of Things weather display example: LCD displays LA current weather via internet Google API
+// Adapted for LCD from http://mbed.org/users/hlipka/programs/spxmltest_weather/lif782 
+TextLCD lcd(p15, p16, p17, p18, p19, p20); // rs, e, d0-d3
+EthernetNetIf eth;
+HTTPClient http;
+HTTPResult result;
+bool completed = false;
+void request_callback(HTTPResult r) {
+    result = r;
+    completed = true;
+}
+
+void parseWeather(SP_XmlElementNode *node) {
+    //extracts current weather XML data fields for LCD 
+    SP_XmlHandle handle(node);
+    SP_XmlElementNode * condition = handle.getChild( "condition" ).toElement();
+    lcd.cls();
+    lcd.printf("LA:");
+    if (condition) {
+        lcd.printf("%s ",condition->getAttrValue("data"));
+    }
+    SP_XmlElementNode * tempf = handle.getChild( "temp_f" ).toElement();
+    if (tempf) {
+        lcd.printf(" %sF\n",tempf->getAttrValue("data"));
+    }
+    SP_XmlElementNode * humidity = handle.getChild( "humidity" ).toElement();
+    if (humidity) {
+        lcd.printf("%s",humidity->getAttrValue("data"));
+    }
+}
+
+int main() {
+    // the eth and HTTP code has be taken directly from the HTTPStream documentation page
+    // see http://mbed.org/cookbook/HTTP-Client-Data-Containers
+    lcd.cls();
+    lcd.printf("net setup");
+    EthernetErr ethErr = eth.setup();
+    if (ethErr) {
+        lcd.printf("\n\rError in setup");
+        return -1;
+    }
+    lcd.printf("\n\r net ok");
+
+    SP_XmlDomParser parser;
+    HTTPStream stream;
+
+    char BigBuf[512 + 1] = {0};
+    stream.readNext((byte*)BigBuf, 512); //Point to buffer for the first read
+    //Google Weather API for Los Angeles - get web page with XML
+    HTTPResult r = http.get("http://www.google.com/ig/api?weather=Los+Angeles", &stream, request_callback);
+    while (!completed) {
+        Net::poll(); //Polls the Networking stack
+        if (stream.readable()) {
+            BigBuf[stream.readLen()] = 0; //Transform this buffer in a zero-terminated char* string
+            parser.append( BigBuf, strlen(BigBuf)); // stream current buffer data to the XML parser
+            stream.readNext((byte*)BigBuf, 512); //Buffer has been read, now we can put more data in it
+        }
+    }
+    lcd.cls();
+    if (result == HTTP_OK) {
+        lcd.printf(" Read complete\n\r");
+    } else {
+        lcd. printf(" Error %d\n", result);
+        return -1;
+    }
+
+    SP_XmlHandle rootHandle( parser.getDocument()->getRootElement() );
+    SP_XmlElementNode * child2 = rootHandle.getChild( "weather" )
+                                 .getChild( "current_conditions").toElement();
+    if ( child2 ) {
+        parseWeather(child2); //parses XML "current-conditions" info
+    }
+
+    if ( NULL != parser.getError() ) {
+        lcd.printf( "\n error: %s\n", parser.getError() );
+    }
+}