W5100 simple UDP protocol development and code analysis (Transalated Version)

Here is my W5100 simple UDP protocol code analysis,using W5100 development board (atmega128)

We can see, UDP and TCP protocols, respectively, in fact, very easy to use, as long as you can call the different functions.

Note the code is as follows:


#include
#include
#include
#include
#include
#include "../header/types.h"
#include "../header/serial.h"
#include "../header/socket.h"
#include "../header/w5100.h"
#define MAX_SIZE 2048
#define RX_BUF 0x1100
#define TX_BUF 0x1900
void main()
{
cli(); // disable interrupt
EICRA=0x00;
EICRB=0x00;
EIMSK=0x00;
EIFR=0x00;
MCUCR = 0x80; // enable external ram
XMCRA=0x40; //define lower sector of memory for EXternal ram and upper sector for W5100C and others
sei(); // enable interrupts
uart_init(0,7);
lcd_init();
uint8 destip[4];
uint8 addr[6];
iinchip_init();
sysinit(0x55,0x55); //
addr[0] = 192; addr[1] = 168; addr[2] = 1; addr[3] = 20;
setSIPR(addr);
addr[0] = 192; addr[1] = 168; addr[2] = 1; addr[3] = 1;
setGAR(addr);
addr[0] = 255; addr[1] = 255; addr[2] = 255; addr[3] = 0;
setSUBR(addr);
memcpy(addr, "\x00\x08\xDC\x00\x00\x00",6);
setSHAR(addr);
uint8 lcd[50];
sprintf(lcd,"IP: %d.%d.%d.%d",IINCHIP_READ(SIPR0),IINCHIP_READ(SIPR0+1),IINCHIP_READ(SIPR0+2),IINCHIP_READ(SIPR0+3));
lcd_puts(lcd); //print LCD string into LCD

uint8 len;
// set UDP mode
socket(0, Sn_MR_UDP, 5000, 0);
// listen(0); //UDP no need to listen
if( getSn_SR(0) == SOCK_UDP)
{
printf("UDP Mode"); // Check socket status register, it is in UDP status
}
while(getSn_RX_RSR(0) ==0 ); // if got data, RX buffer over 0, while loop will end
printf("got data \r\n");
len = getSn_RX_RSR(0); // get length of data received
uint8 * TX_BUFFER = (uint8 *) TX_BUF;
uint8 * RX_BUFFER = (uint8 *) RX_BUF; // make transmit and receive buffer
if( len > MAX_SIZE)
len = MAX_SIZE; // limit the length of data to be copy into TX/RX buffer as MAX
//extern uint16 send(SOCKET s, const uint8 * buf, uint16 len); // Send data (TCP)
//extern uint16 recv(SOCKET s, uint8 * buf, uint16 len); // Receive data (TCP)
//extern uint16 sendto(SOCKET s, const uint8 * buf, uint16 len, uint8 * addr, uint16 port); // Send data (UDP/IP RAW)
//extern uint16 recvfrom(SOCKET s, uint8 * buf, uint16 len, uint8 * addr, uint16 *port); // Receive data (UDP/IP RAW)
//sendto and recvfrom are used for UDP, in contrast, TCP uses send and recv function
// because TCP is connection oriented, once connection is established, no need to assign send to which or receive from which client
len = recvfrom(0,RX_BUFFER,len, destip, 5000); //receive into RX buffer
printf("the size is %u \r\n",len);


printf("%s",RX_BUFFER);
// printf("%02x",*(RX_BUFFER + 1));
// printf("%02x",*(RX_BUFFER +2) );
// in case of more than one character, print 0, 1, 2 address
sendto(0,RX_BUFFER,len,destip, 5000); //send RX buffer to client
}


Translated from Johnny Yan,posted on 28/09/2009
The direct link (Chinese Version): http://blog.sina.com.cn/s/blog_61b952280100f8qj.html