ethernet - Live RSS feeds from ethernet on a 16X2 LCD

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Ameya Ainapure / Mbed 2 deprecated ethernet

Live RSS feeds from ethernet on a 16X2 LCD

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	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	12 Oct 2010
Imports:	42
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	4
Followers:	2

main.cpp@0:92d9235b910a, 2010-10-12 (annotated)

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