udp_send.c

embedded_ethernet_complete_code_rabbit

// The Rabbit sends periodic datagrams to a remote host.
// A timer determines the time between datagrams.

// This file and other embedded Ethernet and Internet code and resources are
// available from www.Lvr.com.

// Select a network configuration from \lib\tcpip\tcp_config.lib
// in the Dynamic C distribution.
#define TCPCONFIG 1

// The local port to send datagrams from
#define LOCAL_PORT	   5551

// The IP address and port to send datagrams to.
// If REMOTE_IP is a host name, you must define MY_NAMESERVER
// in tcp_config.lib or this application.
#define REMOTE_IP			"192.168.111.5"
#define REMOTE_PORT	   5550

//Allocate a socket buffer for the UDP socket.
#define MAX_UDP_SOCKET_BUFFERS 1

// All C functions not declared as root go to extended memory.
#memmap xmem

// The dcrtcp library supports UDP and IP communications.
#use "dcrtcp.lib"

//The socket to use for UDP communications.
udp_Socket my_socket;

int sequence;

main() {

	// Initialize network support and send datagrams.

   int return_value;
   sequence = 255;

   // sock_init must be called before using other functions in dcrtcp.lib.
   // If return_value isn't zero, the network isn't available.
	return_value = sock_init();
	if (return_value == 0) {
	  printf("Nework support is initialized.\n");
	   }
   else {
      printf("The network is not available.\n");
      exit(0);
      }

	// Attempt to open the UDP socket using the specified IP address and port
   // numbers.
   // If udp_open fails, stop the program.
   // The resolve() function converts an IP address in dotted-quad format
   // or a host name to an IP address expresses as a longword.
   if(!udp_open(&my_socket, LOCAL_PORT, resolve(REMOTE_IP), REMOTE_PORT, NULL)) {
      printf("udp_open failed.\n");
      exit(0);
      }
   else {
	   printf("udp_open succeeded.\n");
   }

	// Port G bit 6 controls LED DS1 on the RCM3200 development board.
	// Set bit 6 in PGDDR to configure the bit as an output.
	WrPortI(PGDDR, NULL, 0x40);

	while(1) {

		// Endless loop.

      // Process network packets.
		tcp_tick(NULL);
		costate {

			//wait DelaySec seconds between sends.
			waitfor(DelaySec(1));

			//send a datagram to the remote host.
			send_packet();
		}
	} // end while(1)
} // end main()

int send_packet(void) {

// send a datagram to the remote host.

	char send_buffer[2];
	int buffer_length;
	int return_value;
   int test_bit;

	// Increment the sequence number and reset to zero after sending 255.
	sequence++;
	if (sequence > 255) {
		sequence = 0;
		}

	// Place the bytes to send in send_buffer.

   // The first byte in the datagram is the sequence number.
   send_buffer[0] = (char)sequence;

   // Code to send text messages (requires larger send_buffer).
  	//sprintf(send_buffer, "Message number %d", sequence);

   // The second byte in the datagram is the state of Port G, bit 6.
   test_bit = (BitRdPortI(PGDR, 6));
   send_buffer[1] = (char)test_bit;

   // Toggle the port bit on every send.
	if (test_bit == 0) {

		// When the bit is 0, the LED is on, so switch it off.
		BitWrPortI(PGDR, &PGDRShadow, 1, 6);
	   }
	else {

		// When the bit is 1, the LED is off, so switch it on.
		BitWrPortI(PGDR, &PGDRShadow, 0, 6);
 		}

	// Send the datagram using Dynamic C's udp_send function.
	// my_socket is the UDP socket.
	// send_buffer contains the data to send.
	// sizeof(send_buffer is the number of bytes in send_buffer to send.
	// On success, returns the number of bytes sent.
	return_value = udp_send(&my_socket, send_buffer, sizeof(send_buffer));

	if (return_value < 0) {

	   // On failure, close the socket and attempt to reopen it.
		printf("Error sending datagram.  Closing and reopening socket.\n");
		sock_close(&my_socket);

		// If reopening fails, stop the program.
		if(!udp_open(&my_socket, LOCAL_PORT, resolve(REMOTE_IP), REMOTE_PORT, NULL)) {
			printf("udp_open failed.\n");
			exit(0);
		}
	}
	else {
      printf("Sent: %d %d \n", send_buffer[0], send_buffer[1]);
		}
	return 1;
} // end send_packet()