Diff: main.cpp

Revision:

0:92d9235b910a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Oct 12 14:19:29 2010 +0000
@@ -0,0 +1,215 @@
+#include "mbed.h"
+#include "EthernetNetIf.h"
+#include "HTTPClient.h"
+#include "TextLCD.h"
+//#include "TextLCD_SlideMessage.cpp"
+TextLCD lcd(p10, p12, p15, p16, p29, p30);
+EthernetNetIf eth; 
+HTTPClient http;
+int p=0;
+int c=0;
+int gl=0;
+HTTPResult result;
+bool completed = false;
+
+void request_callback(HTTPResult r)
+{
+  result = r;
+  completed = true;
+}
+
+int checks(char *a)    // parsing function returns the startin poshition of the RSS feed in the current buffer 
+{
+ 
+  int i=gl;
+ // printf("%d\n\r",i);
+  if(p==1)
+  {
+        p=0;
+        if(a[0]=='t')
+        {
+          //c=1;
+          gl=i+8;
+          return i+7;
+        }      
+    }  
+  for(;i<512;i++)
+  {
+  // printf("%d",i);
+    if(i==511)
+    {
+        if(a[i]=='<')
+        {
+            p=1;
+            gl=0;
+            return -1;
+        } 
+    else
+    {
+        gl=0;
+        return -1;
+    }  
+   }
+    if (a[i]=='<')              //  check if "<t" appears 
+    {
+       if(a[i+1]=='t')
+        {
+        //if(a[i+2]=='i')
+        {
+          //c=1;
+          
+         // printf("%c",a[i+2]);
+          if(i+7>511)
+          {
+             c=(i+7-511);
+             gl=0;
+             return -1;
+            } 
+            else
+            {
+            gl=i+8;
+             return i+7;         // return the starting position of the feed
+             }
+          }
+       }
+    }
+  }
+  }
+int main() {
+
+  int i=0;
+  printf("Start\n");
+
+  printf("Setting up...\n");
+  EthernetErr ethErr = eth.setup();
+  if(ethErr)
+  {
+    printf("Error %d in setup.\n", ethErr);
+    return -1;
+  }
+  printf("Setup OK\n");
+  
+  HTTPStream stream;
+ while(1)
+ {
+  completed=false;
+  char BigBuf[512 + 1] = {0};
+  stream.readNext((byte*)BigBuf, 512); //Point to buffer for the first read
+  
+  HTTPResult r = http.get("HTTP://rss.cnn.com/rss/cnn_tech.rss", &stream, request_callback); //Load a very large page, such as the hackaday RSS feed
+  
+  while(!completed)
+  {
+    Net::poll(); //Polls the Networking stack
+    //printf("a");
+    if(stream.readable())
+    {
+      
+    
+     int cnt=0;
+     while(cnt!=-1)   // cnt = -1 if the current buffer is fully read
+   {
+     if (c!=0)
+     {
+        i=c-1;
+        c=0;
+        goto abcd;
+      }   
+       
+       cnt=checks(BigBuf);
+       if(cnt==-1)
+       {
+         break;
+         }
+         printf("\n\r");
+     // printf("%d",cnt ); 
+     i =cnt;
+abcd:  
+     {
+     
+                                                 // Print on LCD in rolling fashion    
+      {        
+         for (j = 15  ; j>=0 ; j-- ){
+      
+             for (int k = j ; k <= 15 ; k++ ){
+               if((i+k-j)==512)
+                {
+                i=-10; 
+                goto efgh;
+                
+                }
+                 lcd.locate(k,0);
+                 if ( BigBuf[i+k-j]!='<' )             // Checks for the end of RSS feed
+                   lcd.printf("%c",BigBuf[i+k-j]) ;
+                 else
+                 {
+                     lcd.cls();
+                     goto efgh;
+                  }   
+             }          
+             wait(0.18) ;
+         }
+         
+         for ( int j = 1 ; BigBuf[i+j] != '<'  ; j++ ){
+             for ( int k = 0; k < 16 ; k++ ){
+                 if((i+k+j)==512)
+                { 
+                i=-10;
+                goto efgh;
+                
+                }
+                  lcd.locate(k,0) ;
+                  
+                 if( BigBuf[i+k + j]!='<' )
+                 {                     
+                     lcd.printf("%c",BigBuf[i+k+j]) ;
+                     }
+                 else
+                 {
+                     lcd.printf(" ") ;
+                     lcd.cls();
+                     goto efgh;
+             }
+             }
+             wait(0.18) ;
+         }    
+   }
+      
+      
+      
+efgh:  if(i==-10)   //  If the buffer is full and the entire feed is not gisplayed
+     {
+       
+       c=1;
+      goto xyz;
+      }                                   
+      }
+     
+    }
+    
+           
+                                      
+xyz:    stream.readNext((byte*)BigBuf, 512); //Buffer has been read, now we can put more data in it
+    }
+  }
+  
+  
+  printf("\n--------------\n");
+  if(result == HTTP_OK)
+  {
+    printf("Read completely\n"); 
+  }
+  else
+  {
+    printf("Error %d\n", result);
+  }
+  wait(5);           // Continuously receive feeds
+  }
+  while(1)
+  {
+  
+  }
+  
+  return 0;
+  
+}