Displays weather info on text LCD using Google API
Dependencies: NetServices TextLCD mbed spxml HTTPClient_ToBeRemoved
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() ); + } +}