Live RSS feeds from ethernet on a 16X2 LCD
Dependencies: EthernetNetIf mbed
main.cpp@0:92d9235b910a, 2010-10-12 (annotated)
- Committer:
- amli1016
- Date:
- Tue Oct 12 14:19:29 2010 +0000
- Revision:
- 0:92d9235b910a
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
amli1016 | 0:92d9235b910a | 1 | #include "mbed.h" |
amli1016 | 0:92d9235b910a | 2 | #include "EthernetNetIf.h" |
amli1016 | 0:92d9235b910a | 3 | #include "HTTPClient.h" |
amli1016 | 0:92d9235b910a | 4 | #include "TextLCD.h" |
amli1016 | 0:92d9235b910a | 5 | //#include "TextLCD_SlideMessage.cpp" |
amli1016 | 0:92d9235b910a | 6 | TextLCD lcd(p10, p12, p15, p16, p29, p30); |
amli1016 | 0:92d9235b910a | 7 | EthernetNetIf eth; |
amli1016 | 0:92d9235b910a | 8 | HTTPClient http; |
amli1016 | 0:92d9235b910a | 9 | int p=0; |
amli1016 | 0:92d9235b910a | 10 | int c=0; |
amli1016 | 0:92d9235b910a | 11 | int gl=0; |
amli1016 | 0:92d9235b910a | 12 | HTTPResult result; |
amli1016 | 0:92d9235b910a | 13 | bool completed = false; |
amli1016 | 0:92d9235b910a | 14 | |
amli1016 | 0:92d9235b910a | 15 | void request_callback(HTTPResult r) |
amli1016 | 0:92d9235b910a | 16 | { |
amli1016 | 0:92d9235b910a | 17 | result = r; |
amli1016 | 0:92d9235b910a | 18 | completed = true; |
amli1016 | 0:92d9235b910a | 19 | } |
amli1016 | 0:92d9235b910a | 20 | |
amli1016 | 0:92d9235b910a | 21 | int checks(char *a) // parsing function returns the startin poshition of the RSS feed in the current buffer |
amli1016 | 0:92d9235b910a | 22 | { |
amli1016 | 0:92d9235b910a | 23 | |
amli1016 | 0:92d9235b910a | 24 | int i=gl; |
amli1016 | 0:92d9235b910a | 25 | // printf("%d\n\r",i); |
amli1016 | 0:92d9235b910a | 26 | if(p==1) |
amli1016 | 0:92d9235b910a | 27 | { |
amli1016 | 0:92d9235b910a | 28 | p=0; |
amli1016 | 0:92d9235b910a | 29 | if(a[0]=='t') |
amli1016 | 0:92d9235b910a | 30 | { |
amli1016 | 0:92d9235b910a | 31 | //c=1; |
amli1016 | 0:92d9235b910a | 32 | gl=i+8; |
amli1016 | 0:92d9235b910a | 33 | return i+7; |
amli1016 | 0:92d9235b910a | 34 | } |
amli1016 | 0:92d9235b910a | 35 | } |
amli1016 | 0:92d9235b910a | 36 | for(;i<512;i++) |
amli1016 | 0:92d9235b910a | 37 | { |
amli1016 | 0:92d9235b910a | 38 | // printf("%d",i); |
amli1016 | 0:92d9235b910a | 39 | if(i==511) |
amli1016 | 0:92d9235b910a | 40 | { |
amli1016 | 0:92d9235b910a | 41 | if(a[i]=='<') |
amli1016 | 0:92d9235b910a | 42 | { |
amli1016 | 0:92d9235b910a | 43 | p=1; |
amli1016 | 0:92d9235b910a | 44 | gl=0; |
amli1016 | 0:92d9235b910a | 45 | return -1; |
amli1016 | 0:92d9235b910a | 46 | } |
amli1016 | 0:92d9235b910a | 47 | else |
amli1016 | 0:92d9235b910a | 48 | { |
amli1016 | 0:92d9235b910a | 49 | gl=0; |
amli1016 | 0:92d9235b910a | 50 | return -1; |
amli1016 | 0:92d9235b910a | 51 | } |
amli1016 | 0:92d9235b910a | 52 | } |
amli1016 | 0:92d9235b910a | 53 | if (a[i]=='<') // check if "<t" appears |
amli1016 | 0:92d9235b910a | 54 | { |
amli1016 | 0:92d9235b910a | 55 | if(a[i+1]=='t') |
amli1016 | 0:92d9235b910a | 56 | { |
amli1016 | 0:92d9235b910a | 57 | //if(a[i+2]=='i') |
amli1016 | 0:92d9235b910a | 58 | { |
amli1016 | 0:92d9235b910a | 59 | //c=1; |
amli1016 | 0:92d9235b910a | 60 | |
amli1016 | 0:92d9235b910a | 61 | // printf("%c",a[i+2]); |
amli1016 | 0:92d9235b910a | 62 | if(i+7>511) |
amli1016 | 0:92d9235b910a | 63 | { |
amli1016 | 0:92d9235b910a | 64 | c=(i+7-511); |
amli1016 | 0:92d9235b910a | 65 | gl=0; |
amli1016 | 0:92d9235b910a | 66 | return -1; |
amli1016 | 0:92d9235b910a | 67 | } |
amli1016 | 0:92d9235b910a | 68 | else |
amli1016 | 0:92d9235b910a | 69 | { |
amli1016 | 0:92d9235b910a | 70 | gl=i+8; |
amli1016 | 0:92d9235b910a | 71 | return i+7; // return the starting position of the feed |
amli1016 | 0:92d9235b910a | 72 | } |
amli1016 | 0:92d9235b910a | 73 | } |
amli1016 | 0:92d9235b910a | 74 | } |
amli1016 | 0:92d9235b910a | 75 | } |
amli1016 | 0:92d9235b910a | 76 | } |
amli1016 | 0:92d9235b910a | 77 | } |
amli1016 | 0:92d9235b910a | 78 | int main() { |
amli1016 | 0:92d9235b910a | 79 | |
amli1016 | 0:92d9235b910a | 80 | int i=0; |
amli1016 | 0:92d9235b910a | 81 | printf("Start\n"); |
amli1016 | 0:92d9235b910a | 82 | |
amli1016 | 0:92d9235b910a | 83 | printf("Setting up...\n"); |
amli1016 | 0:92d9235b910a | 84 | EthernetErr ethErr = eth.setup(); |
amli1016 | 0:92d9235b910a | 85 | if(ethErr) |
amli1016 | 0:92d9235b910a | 86 | { |
amli1016 | 0:92d9235b910a | 87 | printf("Error %d in setup.\n", ethErr); |
amli1016 | 0:92d9235b910a | 88 | return -1; |
amli1016 | 0:92d9235b910a | 89 | } |
amli1016 | 0:92d9235b910a | 90 | printf("Setup OK\n"); |
amli1016 | 0:92d9235b910a | 91 | |
amli1016 | 0:92d9235b910a | 92 | HTTPStream stream; |
amli1016 | 0:92d9235b910a | 93 | while(1) |
amli1016 | 0:92d9235b910a | 94 | { |
amli1016 | 0:92d9235b910a | 95 | completed=false; |
amli1016 | 0:92d9235b910a | 96 | char BigBuf[512 + 1] = {0}; |
amli1016 | 0:92d9235b910a | 97 | stream.readNext((byte*)BigBuf, 512); //Point to buffer for the first read |
amli1016 | 0:92d9235b910a | 98 | |
amli1016 | 0:92d9235b910a | 99 | 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 |
amli1016 | 0:92d9235b910a | 100 | |
amli1016 | 0:92d9235b910a | 101 | while(!completed) |
amli1016 | 0:92d9235b910a | 102 | { |
amli1016 | 0:92d9235b910a | 103 | Net::poll(); //Polls the Networking stack |
amli1016 | 0:92d9235b910a | 104 | //printf("a"); |
amli1016 | 0:92d9235b910a | 105 | if(stream.readable()) |
amli1016 | 0:92d9235b910a | 106 | { |
amli1016 | 0:92d9235b910a | 107 | |
amli1016 | 0:92d9235b910a | 108 | |
amli1016 | 0:92d9235b910a | 109 | int cnt=0; |
amli1016 | 0:92d9235b910a | 110 | while(cnt!=-1) // cnt = -1 if the current buffer is fully read |
amli1016 | 0:92d9235b910a | 111 | { |
amli1016 | 0:92d9235b910a | 112 | if (c!=0) |
amli1016 | 0:92d9235b910a | 113 | { |
amli1016 | 0:92d9235b910a | 114 | i=c-1; |
amli1016 | 0:92d9235b910a | 115 | c=0; |
amli1016 | 0:92d9235b910a | 116 | goto abcd; |
amli1016 | 0:92d9235b910a | 117 | } |
amli1016 | 0:92d9235b910a | 118 | |
amli1016 | 0:92d9235b910a | 119 | cnt=checks(BigBuf); |
amli1016 | 0:92d9235b910a | 120 | if(cnt==-1) |
amli1016 | 0:92d9235b910a | 121 | { |
amli1016 | 0:92d9235b910a | 122 | break; |
amli1016 | 0:92d9235b910a | 123 | } |
amli1016 | 0:92d9235b910a | 124 | printf("\n\r"); |
amli1016 | 0:92d9235b910a | 125 | // printf("%d",cnt ); |
amli1016 | 0:92d9235b910a | 126 | i =cnt; |
amli1016 | 0:92d9235b910a | 127 | abcd: |
amli1016 | 0:92d9235b910a | 128 | { |
amli1016 | 0:92d9235b910a | 129 | |
amli1016 | 0:92d9235b910a | 130 | // Print on LCD in rolling fashion |
amli1016 | 0:92d9235b910a | 131 | { |
amli1016 | 0:92d9235b910a | 132 | for (j = 15 ; j>=0 ; j-- ){ |
amli1016 | 0:92d9235b910a | 133 | |
amli1016 | 0:92d9235b910a | 134 | for (int k = j ; k <= 15 ; k++ ){ |
amli1016 | 0:92d9235b910a | 135 | if((i+k-j)==512) |
amli1016 | 0:92d9235b910a | 136 | { |
amli1016 | 0:92d9235b910a | 137 | i=-10; |
amli1016 | 0:92d9235b910a | 138 | goto efgh; |
amli1016 | 0:92d9235b910a | 139 | |
amli1016 | 0:92d9235b910a | 140 | } |
amli1016 | 0:92d9235b910a | 141 | lcd.locate(k,0); |
amli1016 | 0:92d9235b910a | 142 | if ( BigBuf[i+k-j]!='<' ) // Checks for the end of RSS feed |
amli1016 | 0:92d9235b910a | 143 | lcd.printf("%c",BigBuf[i+k-j]) ; |
amli1016 | 0:92d9235b910a | 144 | else |
amli1016 | 0:92d9235b910a | 145 | { |
amli1016 | 0:92d9235b910a | 146 | lcd.cls(); |
amli1016 | 0:92d9235b910a | 147 | goto efgh; |
amli1016 | 0:92d9235b910a | 148 | } |
amli1016 | 0:92d9235b910a | 149 | } |
amli1016 | 0:92d9235b910a | 150 | wait(0.18) ; |
amli1016 | 0:92d9235b910a | 151 | } |
amli1016 | 0:92d9235b910a | 152 | |
amli1016 | 0:92d9235b910a | 153 | for ( int j = 1 ; BigBuf[i+j] != '<' ; j++ ){ |
amli1016 | 0:92d9235b910a | 154 | for ( int k = 0; k < 16 ; k++ ){ |
amli1016 | 0:92d9235b910a | 155 | if((i+k+j)==512) |
amli1016 | 0:92d9235b910a | 156 | { |
amli1016 | 0:92d9235b910a | 157 | i=-10; |
amli1016 | 0:92d9235b910a | 158 | goto efgh; |
amli1016 | 0:92d9235b910a | 159 | |
amli1016 | 0:92d9235b910a | 160 | } |
amli1016 | 0:92d9235b910a | 161 | lcd.locate(k,0) ; |
amli1016 | 0:92d9235b910a | 162 | |
amli1016 | 0:92d9235b910a | 163 | if( BigBuf[i+k + j]!='<' ) |
amli1016 | 0:92d9235b910a | 164 | { |
amli1016 | 0:92d9235b910a | 165 | lcd.printf("%c",BigBuf[i+k+j]) ; |
amli1016 | 0:92d9235b910a | 166 | } |
amli1016 | 0:92d9235b910a | 167 | else |
amli1016 | 0:92d9235b910a | 168 | { |
amli1016 | 0:92d9235b910a | 169 | lcd.printf(" ") ; |
amli1016 | 0:92d9235b910a | 170 | lcd.cls(); |
amli1016 | 0:92d9235b910a | 171 | goto efgh; |
amli1016 | 0:92d9235b910a | 172 | } |
amli1016 | 0:92d9235b910a | 173 | } |
amli1016 | 0:92d9235b910a | 174 | wait(0.18) ; |
amli1016 | 0:92d9235b910a | 175 | } |
amli1016 | 0:92d9235b910a | 176 | } |
amli1016 | 0:92d9235b910a | 177 | |
amli1016 | 0:92d9235b910a | 178 | |
amli1016 | 0:92d9235b910a | 179 | |
amli1016 | 0:92d9235b910a | 180 | efgh: if(i==-10) // If the buffer is full and the entire feed is not gisplayed |
amli1016 | 0:92d9235b910a | 181 | { |
amli1016 | 0:92d9235b910a | 182 | |
amli1016 | 0:92d9235b910a | 183 | c=1; |
amli1016 | 0:92d9235b910a | 184 | goto xyz; |
amli1016 | 0:92d9235b910a | 185 | } |
amli1016 | 0:92d9235b910a | 186 | } |
amli1016 | 0:92d9235b910a | 187 | |
amli1016 | 0:92d9235b910a | 188 | } |
amli1016 | 0:92d9235b910a | 189 | |
amli1016 | 0:92d9235b910a | 190 | |
amli1016 | 0:92d9235b910a | 191 | |
amli1016 | 0:92d9235b910a | 192 | xyz: stream.readNext((byte*)BigBuf, 512); //Buffer has been read, now we can put more data in it |
amli1016 | 0:92d9235b910a | 193 | } |
amli1016 | 0:92d9235b910a | 194 | } |
amli1016 | 0:92d9235b910a | 195 | |
amli1016 | 0:92d9235b910a | 196 | |
amli1016 | 0:92d9235b910a | 197 | printf("\n--------------\n"); |
amli1016 | 0:92d9235b910a | 198 | if(result == HTTP_OK) |
amli1016 | 0:92d9235b910a | 199 | { |
amli1016 | 0:92d9235b910a | 200 | printf("Read completely\n"); |
amli1016 | 0:92d9235b910a | 201 | } |
amli1016 | 0:92d9235b910a | 202 | else |
amli1016 | 0:92d9235b910a | 203 | { |
amli1016 | 0:92d9235b910a | 204 | printf("Error %d\n", result); |
amli1016 | 0:92d9235b910a | 205 | } |
amli1016 | 0:92d9235b910a | 206 | wait(5); // Continuously receive feeds |
amli1016 | 0:92d9235b910a | 207 | } |
amli1016 | 0:92d9235b910a | 208 | while(1) |
amli1016 | 0:92d9235b910a | 209 | { |
amli1016 | 0:92d9235b910a | 210 | |
amli1016 | 0:92d9235b910a | 211 | } |
amli1016 | 0:92d9235b910a | 212 | |
amli1016 | 0:92d9235b910a | 213 | return 0; |
amli1016 | 0:92d9235b910a | 214 | |
amli1016 | 0:92d9235b910a | 215 | } |