Issues with TCP on Arduino

问题

I am experimenting with my Arduino Leonardo and a simple C socket server. The C part must send a string to the Arduino but I cannot connect to the arduino (after the socket is initialized C function is blocked and can not connect to Arduino). The C function code is:

#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib") //Winsock Library

int connect() {
  WSADATA wsa;
  SOCKET s;
  struct sockaddr_in server;
  char* message;
  printf("\nInitialising Winsock...");
  if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0) {
    printf("Failed. Error Code : %d", WSAGetLastError());
    return 1;
  }
  printf("Initialised.\n");
  //Create a socket
  if ((s = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
    printf("Could not create socket : %d", WSAGetLastError());
  } else printf("Socket created.\n");
  server.sin_addr.s_addr = inet_addr("192.168.1.144");
  server.sin_family = AF_INET;
  server.sin_port = htons(9600);

  //Connect to remote server
  //HERE I RECEIVE THE ERROR: <---------------------------
  if (connect(s, (struct sockaddr*)&server, sizeof(server)) < 0) {
    puts("connect error");
    return 1;
  }
  puts("Connected");
  //Send some data
  message = "This is a Test\n";
  if (send(s, message, strlen(message), 0) < 0) {
    puts("Send failed");
    return 1;
  }
  puts("Data Send\n");
  return 0;
}

The Arduino code is:

#include <SPI.h>
#include <Ethernet.h>

//Mac and Ip of Arduino
byte mac[]
  = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 1, 144);

EthernetServer server(23); // Set Server Port
boolean alreadyConnected = false; // whether or not the client was connected
previously

void setup() {
  Serial.begin(9600);
  // initialize the ethernet device
  Ethernet.begin(mac, ip);
  server.begin();
  //print out the IP address
  Serial.print("IP = ");
  Serial.println(Ethernet.localIP());
}

void loop() {
  // wait for a new client:
  EthernetClient client = server.available();
  // when the client sends the first byte, say hello:
  if (client) {
    if (!alreadyConnected) {
      // clear out the input buffer:
      client.flush();
      Serial.println("We have a new client");
      client.println("Hello, client!");
      alreadyConnected = true;
    }
    if (client.available() > 0) {
      // read the bytes incoming from the client:
      char thisChar = client.read();
      // echo the bytes back to the client:
      server.write(thisChar);
      // echo the bytes to the server as well:
      Serial.write(thisChar);
    }
  }
}

What I'm doing wrong? Thank you!

来源：https://stackoverflow.com/questions/49350333/issues-with-tcp-on-arduino

标签

sockets

tcp

arduino

ethernet