main.cpp

00001 #include "mbed.h"
00002 #include "EthernetNetIf.h"
00003 #include "HTTPClient.h"
00004 #include "TextLCD.h"
00005 //CNN Tech News RSS Feed - get web page with XML
00006 // displays titles on LCD  from XML "<title>....title text...</title>"
00007 TextLCD lcd(p15, p16, p17, p18, p19, p20); // rs, e, d0-d3
00008 EthernetNetIf eth;
00009 HTTPClient http;
00010 HTTPResult result;
00011 PwmOut speaker(p21);
00012 bool completed = false;
00013 void request_callback(HTTPResult r)
00014 {
00015     result = r;
00016     completed = true;
00017 }
00018 
00019 int main()
00020 {
00021     //while(1) {
00022     char *tstartXML = "<title>"; //RSS XML start title
00023     char *tendXML ="</title>"; //RSS XML end title
00024     char *tsptr;
00025     char *teptr;
00026     int i=0,j=0,t=0,c=0,d=0;
00027     lcd.cls();
00028     lcd.printf("net setup");
00029     EthernetErr ethErr = eth.setup();
00030     if (ethErr) {
00031         lcd.printf("\n\r net error");
00032         return -1;
00033     }
00034     lcd.printf("\n\r net ok");
00035     HTTPStream stream;
00036     char BigBuf[2048 + 1] = {0};
00037     stream.readNext((byte*)BigBuf, 2048); //Point to buffer for the first read
00038     //CNN Tech News RSS Feed - get web page with XML
00039     HTTPResult r = http.get("http://alerts.weather.gov/cap/wwaatmget.php?x=GAC121&y=0", &stream, request_callback);
00040     while (!completed) {
00041         c=0;
00042         Net::poll(); // Polls the Networking stack
00043         if (stream.readable()) { // check for end of file
00044             BigBuf[stream.readLen()] = 0; // Transform this buffer in a zero-terminated char* string
00045             tsptr = BigBuf;
00046             // displays titles on LCD  from XML "<title>....title text...</title>"
00047             do {
00048                 tsptr = strstr(tsptr,tstartXML); // find <title> in string - NULL if not
00049                 teptr = strstr(tsptr,tendXML); // find <\title> in string - NULL if not
00050                 if (tsptr!=NULL) tsptr = tsptr + strlen(tstartXML);// move to char after "<title>"
00051                 if ((tsptr!=NULL)&&(teptr!=NULL)) {
00052                     i=0;
00053                     // loop to scroll characters slowly across LCD
00054                     for (j=0; (j+15)<(strlen(tsptr)-strlen(teptr)); j++) {
00055                         lcd.cls(); // clear screen before writing a new line
00056                         // loop to output a line on the LCD
00057                         for (i=0; ((i<16)&&(tsptr[i+j-1] != '<')); i++) {
00058                             c++;
00059                         }
00060                         i=0;
00061                         if (t>0 && c> 51 && d==0 && c!=108) {
00062                             speaker.period(1.0/500.0); // 500hz period
00063                             speaker =0.5; //50% duty cycle - max volume
00064                             wait(2.5);
00065                             speaker=0.0; // turn off audio
00066                             wait(1);
00067                             speaker =0.5; //50% duty cycle - max volume
00068                             wait(2.5);
00069                             speaker=0.0; // turn off audio
00070                             wait(1);
00071                             i=0;
00072                             d=1;
00073                         }
00074                         for (i=0; ((i<16)&&(tsptr[i+j-1] != '<')); i++) {
00075                             lcd.putc(tsptr[i+j]);
00076                         }
00077                         if (j==0) wait(1.2); //add first line delays for scroll timing
00078                         wait(.25); //delay for charcter scroll timing
00079                     }
00080                     wait(.4);
00081                     lcd.cls(); //clear LCD between news items
00082                     wait(.2);
00083 
00084                 }
00085 
00086             } while (tsptr!=NULL); // No more "<title>"s in BigBuf to display
00087             stream.readNext((byte*)BigBuf, 2048); //Buffer has been read, now we can put more data in it
00088             c=0;
00089             t++;
00090         }
00091     }
00092     lcd.cls();
00093     if (result == HTTP_OK) {
00094         lcd.cls();
00095         lcd.printf(" Read complete\n\r");
00096 
00097     } else {
00098         lcd. printf(" Error %d\n", result);
00099         return -1;
00100     }
00101     // }
00102 }