Data transfer on ethernet

[kapil_p]

Hi

I am trying to build a communication from serial to ethernet and ethernet to serial.

By using the tcp_echo example i am trying to build the above communication . The ethernet to serial is working (transferred a data using packet sender and data is received in tcpecho.c file and same data is given to uart ).

Now to build the serial to ethernet communication , not understanding where to put  data which is received from the serial.

I given the data received from the serial  to tcp_write( ) in tcpecho_raw.c file but it is not working.

Not understanding how tcpecho_raw.c is working.

Thank you.

Kapil Patil.

[FelipeGarcia]

Hello Kapil,

Could you please specify which MCU are you working on? Thanks.

Best regards,

Felipe

[kapil_p]

Hello Felipe Garcia

I am using a FRDM K64-F development board.

Once again I am explaining my problem. I know it is difficult to understand to you but still I am trying to explain.

I want to develop a communication like Ethernet to serial and serial to Ethernet. I am using a lwip tcpecho example. I am successful in Ethernet to serial communication (transferring from TCP and receiving at serial ).

In tcpecho example the data transfer tcpecho_raw_send(tcp,es) function is called in the tcpecho_recv function , here I commented all the tcpecho_raw_send() functions whhich is called inside tcp_raw_recv() function. Now I want to send my own data by using tcpecho_raw_send() but I am confused where to call this function in tcpecho_raw.c file , if I called tcpecho_raw_send function outside the tcpecho_raw_file , I am confuse how to pass the parameters   tcp and es , if I declare this parameters separately in main function then invalid PCB error is generating. On error invalid PCB I understood that , while making a new connection one pcb is generated and the PCB which I am using is not that PCB which is previously created , so again I created a connection like following but again it showing a error the connection is already done for this IP.

void echo_tx_tcp()
{ 

struct tcp_pcb *l_tcp_pcb;
l_tcp_pcb = tcp_new();

 wr_err = tcp_bind(l_tcp_pcb, IP_ANY_TYPE, 7);
tcpecho_raw_pcb = tcp_listen(l_tcp_pcb);
wr_err = tcp_connect(l_tcp_pcb, IP_ANY_TYPE, 7, tcp_accept);

struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, 1024, PBUF_RAM);
unsigned char buffer_send[1024] = "My Name Is TCP";
p->payload = buffer_send;
p->len = 1024;
p->tot_len = 1024;

wr_err = tcp_write(tcpecho_raw_pcb , p->payload, p->len, 1);

}

 The main thing is I want to a separate transfer function where I can put my data received from the serial.

I am using 

IDE = MCUXpresso

board = FRDM K64-F

Thank you.

Kapil Patil

[FelipeGarcia]

Hello Kapil,

If you check tcp_write() function, the second argument is a pointer to the data to be enqueued for sending. How about you change this argument and put your own data instead?

From tcpecho_raw_send()

  struct pbuf *ptr;

  err_t wr_err = ERR_OK;

  while ((wr_err == ERR_OK) &&

         (es->p != NULL) &&

         (es->p->len <= tcp_sndbuf(tpcb))) {

    ptr = es->p;

    /* enqueue data for transmission */

    wr_err = tcp_write(tpcb, ptr->payload, ptr->len, 1);

Please let me know of this helps.

Best regards,

Felipe

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[kapil_p]

Hello Felipe García

Thank you for the reply.

The problem is not changing the argument . In tcpecho_raw_send function I given my own data and it is working fine only when I call the function tcpecho_raw_send()  in tcpecho_raw_recv(). 

         I want to call tcpecho_raw_send() in main file ,  but I am not understanding how to pass a arguments. 

       My transmit function should not depend on the receive function , I want to call this when my serial data is arrive.

I have a problem with the parameters like struct tcp_pcb *tpcb 

tcpecho_raw_send(struct tcp_pcb *tpcb, struct tcpecho_raw_state *es)

static void
tcpecho_raw_send(struct tcp_pcb *tpcb, struct tcpecho_raw_state *es)
{
struct pbuf *ptr;
err_t wr_err = ERR_OK;
char mydata[1024] = "Hello everyone\n";

// tcpecho_raw_init();
while ((wr_err == ERR_OK) &&
(es->p != NULL) &&
(es->p->len <= tcp_sndbuf(tpcb))) {
ptr = es->p;

wr_err = tcp_write(tpcb, "FRDM K64-F",10, 1);  // This is working fine 

if (wr_err == ERR_OK) {
u16_t plen;

plen = ptr->len;
/* continue with next pbuf in chain (if any) */
es->p = ptr->next;
if(es->p != NULL) {
/* new reference! */
pbuf_ref(es->p);
}
/* chop first pbuf from chain */
pbuf_free(ptr);
/* we can read more data now */
tcp_recved(tpcb, plen);
} else if(wr_err == ERR_MEM) {
/* we are low on memory, try later / harder, defer to poll */
es->p = ptr;
} else {
/* other problem ?? */
}
}

}

I tried above function like this but invalid pcb error is generated.

static void
tcpecho_raw_send()
{

struct tcp_pcb *new_tpcb;
struct pbuf *ptr;
err_t wr_err = ERR_OK;
char mydata[1024] = "Hello everyone\n";

// tcpecho_raw_init();
while ((wr_err == ERR_OK) &&
(es->p != NULL) &&
(es->p->len <= tcp_sndbuf(tpcb))) {
ptr = es->p;

wr_err = tcp_write(new_tpcb, "FRDM K64-F",10, 1);  // This is working fine 

if (wr_err == ERR_OK) {
u16_t plen;

plen = ptr->len;
/* continue with next pbuf in chain (if any) */
es->p = ptr->next;
if(es->p != NULL) {
/* new reference! */
pbuf_ref(es->p);
}
/* chop first pbuf from chain */
pbuf_free(ptr);
/* we can read more data now */
tcp_recved(tpcb, plen);
} else if(wr_err == ERR_MEM) {
/* we are low on memory, try later / harder, defer to poll */
es->p = ptr;
} else {
/* other problem ?? */
}
}

}

Thank you

Kapil Patil

[FelipeGarcia]

Hello Kapil,

Could you please show me errors you mentioned? Even better if you can share your code with the modifications stated in your previous reply so I can replicate this on my side.

Best regards,

Felipe