jim hamblen
Displays weather info on text LCD using Google API
Dependencies: NetServices TextLCD mbed spxml HTTPClient_ToBeRemoved
main.cpp@0:537d849c3d8c, 2012-04-21 (annotated)
- Committer:
- 4180_1
- Date:
- Sat Apr 21 03:45:58 2012 +0000
- Revision:
- 0:537d849c3d8c
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| 4180_1 | 0:537d849c3d8c | 1 | #include "mbed.h" |
| 4180_1 | 0:537d849c3d8c | 2 | #include "EthernetNetIf.h" |
| 4180_1 | 0:537d849c3d8c | 3 | #include "HTTPClient.h" |
| 4180_1 | 0:537d849c3d8c | 4 | #include "spdomparser.hpp" |
| 4180_1 | 0:537d849c3d8c | 5 | #include "spxmlnode.hpp" |
| 4180_1 | 0:537d849c3d8c | 6 | #include "spxmlhandle.hpp" |
| 4180_1 | 0:537d849c3d8c | 7 | #include "TextLCD.h" |
| 4180_1 | 0:537d849c3d8c | 8 | // Internet of Things weather display example: LCD displays LA current weather via internet Google API |
| 4180_1 | 0:537d849c3d8c | 9 | // Adapted for LCD from http://mbed.org/users/hlipka/programs/spxmltest_weather/lif782 |
| 4180_1 | 0:537d849c3d8c | 10 | TextLCD lcd(p15, p16, p17, p18, p19, p20); // rs, e, d0-d3 |
| 4180_1 | 0:537d849c3d8c | 11 | EthernetNetIf eth; |
| 4180_1 | 0:537d849c3d8c | 12 | HTTPClient http; |
| 4180_1 | 0:537d849c3d8c | 13 | HTTPResult result; |
| 4180_1 | 0:537d849c3d8c | 14 | bool completed = false; |
| 4180_1 | 0:537d849c3d8c | 15 | void request_callback(HTTPResult r) { |
| 4180_1 | 0:537d849c3d8c | 16 | result = r; |
| 4180_1 | 0:537d849c3d8c | 17 | completed = true; |
| 4180_1 | 0:537d849c3d8c | 18 | } |
| 4180_1 | 0:537d849c3d8c | 19 | |
| 4180_1 | 0:537d849c3d8c | 20 | void parseWeather(SP_XmlElementNode *node) { |
| 4180_1 | 0:537d849c3d8c | 21 | //extracts current weather XML data fields for LCD |
| 4180_1 | 0:537d849c3d8c | 22 | SP_XmlHandle handle(node); |
| 4180_1 | 0:537d849c3d8c | 23 | SP_XmlElementNode * condition = handle.getChild( "condition" ).toElement(); |
| 4180_1 | 0:537d849c3d8c | 24 | lcd.cls(); |
| 4180_1 | 0:537d849c3d8c | 25 | lcd.printf("LA:"); |
| 4180_1 | 0:537d849c3d8c | 26 | if (condition) { |
| 4180_1 | 0:537d849c3d8c | 27 | lcd.printf("%s ",condition->getAttrValue("data")); |
| 4180_1 | 0:537d849c3d8c | 28 | } |
| 4180_1 | 0:537d849c3d8c | 29 | SP_XmlElementNode * tempf = handle.getChild( "temp_f" ).toElement(); |
| 4180_1 | 0:537d849c3d8c | 30 | if (tempf) { |
| 4180_1 | 0:537d849c3d8c | 31 | lcd.printf(" %sF\n",tempf->getAttrValue("data")); |
| 4180_1 | 0:537d849c3d8c | 32 | } |
| 4180_1 | 0:537d849c3d8c | 33 | SP_XmlElementNode * humidity = handle.getChild( "humidity" ).toElement(); |
| 4180_1 | 0:537d849c3d8c | 34 | if (humidity) { |
| 4180_1 | 0:537d849c3d8c | 35 | lcd.printf("%s",humidity->getAttrValue("data")); |
| 4180_1 | 0:537d849c3d8c | 36 | } |
| 4180_1 | 0:537d849c3d8c | 37 | } |
| 4180_1 | 0:537d849c3d8c | 38 | |
| 4180_1 | 0:537d849c3d8c | 39 | int main() { |
| 4180_1 | 0:537d849c3d8c | 40 | // the eth and HTTP code has be taken directly from the HTTPStream documentation page |
| 4180_1 | 0:537d849c3d8c | 41 | // see http://mbed.org/cookbook/HTTP-Client-Data-Containers |
| 4180_1 | 0:537d849c3d8c | 42 | lcd.cls(); |
| 4180_1 | 0:537d849c3d8c | 43 | lcd.printf("net setup"); |
| 4180_1 | 0:537d849c3d8c | 44 | EthernetErr ethErr = eth.setup(); |
| 4180_1 | 0:537d849c3d8c | 45 | if (ethErr) { |
| 4180_1 | 0:537d849c3d8c | 46 | lcd.printf("\n\rError in setup"); |
| 4180_1 | 0:537d849c3d8c | 47 | return -1; |
| 4180_1 | 0:537d849c3d8c | 48 | } |
| 4180_1 | 0:537d849c3d8c | 49 | lcd.printf("\n\r net ok"); |
| 4180_1 | 0:537d849c3d8c | 50 | |
| 4180_1 | 0:537d849c3d8c | 51 | SP_XmlDomParser parser; |
| 4180_1 | 0:537d849c3d8c | 52 | HTTPStream stream; |
| 4180_1 | 0:537d849c3d8c | 53 | |
| 4180_1 | 0:537d849c3d8c | 54 | char BigBuf[512 + 1] = {0}; |
| 4180_1 | 0:537d849c3d8c | 55 | stream.readNext((byte*)BigBuf, 512); //Point to buffer for the first read |
| 4180_1 | 0:537d849c3d8c | 56 | //Google Weather API for Los Angeles - get web page with XML |
| 4180_1 | 0:537d849c3d8c | 57 | HTTPResult r = http.get("http://www.google.com/ig/api?weather=Los+Angeles", &stream, request_callback); |
| 4180_1 | 0:537d849c3d8c | 58 | while (!completed) { |
| 4180_1 | 0:537d849c3d8c | 59 | Net::poll(); //Polls the Networking stack |
| 4180_1 | 0:537d849c3d8c | 60 | if (stream.readable()) { |
| 4180_1 | 0:537d849c3d8c | 61 | BigBuf[stream.readLen()] = 0; //Transform this buffer in a zero-terminated char* string |
| 4180_1 | 0:537d849c3d8c | 62 | parser.append( BigBuf, strlen(BigBuf)); // stream current buffer data to the XML parser |
| 4180_1 | 0:537d849c3d8c | 63 | stream.readNext((byte*)BigBuf, 512); //Buffer has been read, now we can put more data in it |
| 4180_1 | 0:537d849c3d8c | 64 | } |
| 4180_1 | 0:537d849c3d8c | 65 | } |
| 4180_1 | 0:537d849c3d8c | 66 | lcd.cls(); |
| 4180_1 | 0:537d849c3d8c | 67 | if (result == HTTP_OK) { |
| 4180_1 | 0:537d849c3d8c | 68 | lcd.printf(" Read complete\n\r"); |
| 4180_1 | 0:537d849c3d8c | 69 | } else { |
| 4180_1 | 0:537d849c3d8c | 70 | lcd. printf(" Error %d\n", result); |
| 4180_1 | 0:537d849c3d8c | 71 | return -1; |
| 4180_1 | 0:537d849c3d8c | 72 | } |
| 4180_1 | 0:537d849c3d8c | 73 | |
| 4180_1 | 0:537d849c3d8c | 74 | SP_XmlHandle rootHandle( parser.getDocument()->getRootElement() ); |
| 4180_1 | 0:537d849c3d8c | 75 | SP_XmlElementNode * child2 = rootHandle.getChild( "weather" ) |
| 4180_1 | 0:537d849c3d8c | 76 | .getChild( "current_conditions").toElement(); |
| 4180_1 | 0:537d849c3d8c | 77 | if ( child2 ) { |
| 4180_1 | 0:537d849c3d8c | 78 | parseWeather(child2); //parses XML "current-conditions" info |
| 4180_1 | 0:537d849c3d8c | 79 | } |
| 4180_1 | 0:537d849c3d8c | 80 | |
| 4180_1 | 0:537d849c3d8c | 81 | if ( NULL != parser.getError() ) { |
| 4180_1 | 0:537d849c3d8c | 82 | lcd.printf( "\n error: %s\n", parser.getError() ); |
| 4180_1 | 0:537d849c3d8c | 83 | } |
| 4180_1 | 0:537d849c3d8c | 84 | } |