Severe weather alert using NOAA RSS feed
Dependencies: NetServices TextLCD mbed spxml
Fork of News_LCD_display by
Diff: main.cpp
- Revision:
- 0:582c6436e759
- Child:
- 1:182ff6aef029
diff -r 000000000000 -r 582c6436e759 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Tue Apr 24 02:27:43 2012 +0000 @@ -0,0 +1,76 @@ +#include "mbed.h" +#include "EthernetNetIf.h" +#include "HTTPClient.h" +#include "TextLCD.h" +//CNN Tech News RSS Feed - get web page with XML +// displays titles on LCD from XML "<title>....title text...</title>" +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; +} + +int main() { + char *tstartXML = "<title>"; //RSS XML start title + char *tendXML ="</title>"; //RSS XML end title + char *tsptr; + char *teptr; + int i=0,j=0; + // 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\r net error"); + return -1; + } + lcd.printf("\n\r net ok"); + HTTPStream stream; + char BigBuf[2048 + 1] = {0}; + stream.readNext((byte*)BigBuf, 2048); //Point to buffer for the first read + //CNN Tech News RSS Feed - get web page with XML + HTTPResult r = http.get("HTTP://rss.cnn.com/rss/cnn_tech.rss", &stream, request_callback); + while (!completed) { + Net::poll(); // Polls the Networking stack + if (stream.readable()) { // check for end of file + BigBuf[stream.readLen()] = 0; // Transform this buffer in a zero-terminated char* string + tsptr = BigBuf; + // displays titles on LCD from XML "<title>....title text...</title>" + do { + tsptr = strstr(tsptr,tstartXML); // find <title> in string - NULL if not + teptr = strstr(tsptr,tendXML); // find <\title> in string - NULL if not + if (tsptr!=NULL) tsptr = tsptr + strlen(tstartXML);// move to char after "<title>" + if ((tsptr!=NULL)&&(teptr!=NULL)) { + i=0; + // loop to scroll characters slowly across LCD + for (j=0; (j+15)<(strlen(tsptr)-strlen(teptr)); j++) { + lcd.cls(); // clear screen before writing a new line + // loop to output a line on the LCD + for (i=0; ((i<16)&&(tsptr[i+j-1] != '<')); i++) { + lcd.putc(tsptr[i+j]); + } + if (j==0) wait(1.2); //add first line delays for scroll timing + wait(.2); //delay for charcter scroll timing + } + wait(.4); + lcd.cls(); //clear LCD between news items + wait(.2); + } + } while (tsptr!=NULL); // No more "<title>"s in BigBuf to display + stream.readNext((byte*)BigBuf, 2048); //Buffer has been read, now we can put more data in it + } + } + lcd.cls(); + if (result == HTTP_OK) { + lcd.cls(); + lcd.printf(" Read complete\n\r"); + } else { + lcd. printf(" Error %d\n", result); + return -1; + } +}