HTTP Client

You have to create a HTTP request.
Connect to the web server.
Send the request.
Retrieve an answer and check the HTTP response.
Figure out if you need to receive a fixed number of bytes or receive until disconnect.
Read your "body" data.
Close connection.

There should be a number of examples to be found with Google how to send an HTTP request and how to parse the response. It isn't related to what TCP/IP stack that is used.

Don't even need to go as far (sic) as Google:

www.keil.com/.../search.asp

Right.
Implementing the client, tcp_connect() returns true. But tcp_get_state() always returns TCP_STATE_SYN_SENT.
After a few seconds is generated TCP_EVT_ABORT event in tcp_callback().

My code:

U8 httpc_soc;

U16 httpc_tcp_callback(U8 soc, U8 event, U8 *ptr, U16 par) {
  switch (event) {
    case TCP_EVT_CONREQ:
      return 1;
    case TCP_EVT_ABORT:
      log_print("httpc: abort %03d.%03d.%03d.%03d:%d\n",
                ptr[0], ptr[1], ptr[2], ptr[3], par);
      tcp_close(soc);
      return 1;
    case TCP_EVT_CONNECT:
      log_print("httpc: connected %03d.%03d.%03d.%03d:%d\n",
                ptr[0], ptr[1], ptr[2], ptr[3], par);
      return 1;
    case TCP_EVT_CLOSE:
      log_print("httpc: close %03d.%03d.%03d.%03d:%d\n",
                ptr[0], ptr[1], ptr[2], ptr[3], par);
      return 1;
    case TCP_EVT_ACK:
      return 1;
    case TCP_EVT_DATA:
      log_print("httpc: rcv message (%d bytes)\n", par);
      log_print("httpc: %s\n", ptr);
      return par;
  }
  return 0;
}

int httpc_send(U8 *server_addr, const char *message) {
  int len = strlen(message);
  U8 *buf = tcp_get_buf((len+4) | 0x8000);
  U8 state, timeout = 0;
  if (!httpc_soc) {
    httpc_soc = tcp_get_socket(TCP_TYPE_CLIENT, 0, 30, httpc_tcp_callback);
    if (!httpc_soc)
      return 0;
  }
  state = tcp_get_state(httpc_soc);
  if (state == TCP_STATE_FREE || state == TCP_STATE_CLOSED) {
    if (tcp_connect(httpc_soc, server_addr, 80, 1000) == __TRUE)
      log_print("httpc: =connect\n");
  }
  state = tcp_get_state(httpc_soc);
  if (state == TCP_STATE_CONNECT) {
    while (tcp_check_send(httpc_soc) != __TRUE && timeout < 10) {
      timeout++;
      os_dly_wait(50);
    }
    if (tcp_check_send(httpc_soc) == __TRUE) {
      if (buf != NULL) {
        mem_copy(buf, (void*)message, len);
        mem_copy(&buf[len-4], "\r\n\r\n", 4);
        if (tcp_send(httpc_soc, buf, len) == __TRUE)
          return 1;
      }
      log_print("httpc: =null\n");
    }
    log_print("httpc: !send\n");
  }
  log_print("httpc: state %d\n", state);
  return 0;
}

__task void httpc_task(void) {
  U8 webserver[4] = {192,168,1,103};

  init_eth(); // eth task && init_TcpNet

  while (1) {
    if (httpc_send(webserver, "GET /myserver/index.php?method=GET&rs=datalog HTTP1.1"))
      log_print("httpc: sent message\n");
    os_dly_wait(10000);
  }
}

Output log:

httpc: =connect
httpc: state 4
httpc: state 4
httpc: state 4
httpc: abort 192.168.1.103:80
httpc: =connect
httpc: state 4
httpc: state 4
httpc: state 4
httpc: abort 192.168.1.103:80