CCS/TM4C1294NCPDT: Ethernet client program development

Hi Charles,

Thanks for your reply. I got a basic understanding of the given information. In the given link the modified enet_lwip is working as a server. I tried to modify it as a client based on this information http://lwip.wikia.com/wiki/Raw/TCP. 

void tcp_setup(void)
{
uint32_t data = 0xdeadbeef;

/* create an ip */
struct ip_addr ip;

IP4_ADDR(&ip, 192,168,0,106); // server IP 

/* create the control block */
testpcb = tcp_new(); //testpcb is a global struct tcp_pcb

tcp_bind(testpcb, &ip, 8999);

tcp_arg(testpcb, &data);

tcp_err(testpcb, echo_error);
tcp_recv(testpcb, tcpRecvCallback);
tcp_sent(testpcb, echo_sent);

/* now connect */
tcp_connect(testpcb, &ip, 8999, connectCallback);

}

Can you suggest what else I need to work it as a client to send the dat?.

Regards,

Saiteja.

Hi,

  Below is only an example. The client sends a "Hello World" to the server.

uint32_t tcp_send_packet(void)
{
    char *string = "Hello World! \n\r ";

    err = tcp_write(testpcb, string, strlen(string), TCP_WRITE_FLAG_COPY);


    if (err) {
        UARTprintf("ERROR: Code: %d (tcp_send_packet :: tcp_write)\n", err);
        return 1;
    }

    /* now send */
    err = tcp_output(testpcb);
    if (err) {
        UARTprintf("ERROR: Code: %d (tcp_send_packet :: tcp_output)\n", err);
        return 1;
    }
    return 0;
}

err_t connectCallback(void *arg, struct tcp_pcb *tpcb, err_t err)
{


    if (err == ERR_OK){

		UARTprintf("Connection Established.\n");


		tcp_recv(testpcb, echo_receive);
		tcp_sent(testpcb, NULL);
		UARTprintf("Sending a greeting message to the Server\n");
		tcp_send_packet();
		return 0;
    } else {
		UARTprintf("No Connection Established.\n");
		return 1;

    }
}

void echo_client_init(void)
{
    /* create an ip */
    struct ip_addr server_addr;


    /* create the control block */
    testpcb = tcp_new();    //testpcb is a global struct tcp_pcb

    if (testpcb != NULL)
    {
        IP4_ADDR(&server_addr, 10,219,15,38);    //IP of the PC computer

		tcp_bind(testpcb, IP_ADDR_ANY, 7000);

		/* now connect */
		err = tcp_connect(testpcb, &server_addr, 8000, connectCallback);
	    if (err) {
	        UARTprintf("ERROR: Code: %d (tcp_connect)\n", err);
	    }

		UARTprintf("PCB CREATED\n");

    } else {
        memp_free(MEMP_TCP_PCB, testpcb);
		UARTprintf("PCB NOT CREATED\n");

    }

}

Hi charles,

I tried with the given changes. Still, the client is not sending any data to a server, even connection is not established. I have given the server IP address(IP4_ADDR(&server_addr, 192,168,0,105)) and its port number is 8004, which is running in the other pc. the bind call is used without any changes. It is pinging fine but not connected to the server. I commented the echo_init and simply calling the client_init. I put the breakpoint in connectCallback function it is not getting to that breakpoint.

Can you please summerise which port belongs to which device in the comment lines?. I tried with the usrtcp application same issue arises. I want to know how you tested the client program. In the main also

Hi charles,

It is working now the connection is established between the TM4C(client) and server in other PC and sending the message. It worked when I placed the echo_client _init() function call in the lwIPHostTimerHandler() function. The continuous messages are not sending I tried with tcp_keepalive(). The same code I made it as a server at that I didn't include the server init function in the lwIPHostTimerHandler() function it worked fine. may I know the reason why it is happening?. 

a part of code snippet in lwIPHostTimerHandler().
// Display the new IP address.
//
UARTprintf("IP Address: ");
DisplayIPAddress(ui32NewIPAddress);
UARTprintf("\nOpen a browser and enter the IP address.\n");
echo_client_init();
//

Now I want to make this TCP client as an HTTP client. I have seen the enet_weather example In that they are using their application api's and enet_lwip is also an HTTP server.  I want to send the simple message to the HTTP server and want to print the response from the server. suggest me the best way.

Regards,

B T S S Sai Prasad 

Hi Charles,

Thanks for your reply. Now I want to send the data continuously but it is aborting after one transfer. I am using this code in a while loop to transfer and receive the data continuously.

while(1)

{

  tcp_write(testpcb, string, strlen(string), TCP_WRITE_FLAG_COPY);

  tcp_recv(testpcb, echo_recv);

delay();

}

After one one transfer it is getting to the abort() which is in the exit.c file. What changes do I need to implement for continuous transfer.

Regards,

B T S S Sai Prasad.