Diff: main.cpp

Revision:

0:582c6436e759

--- /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;
+    }
+}