Socket 통신

Protocol

• packet size : 5 bytes
• [0] : command
• [1] : value
• [2] : reserved
• [3] : reserved
• [4] : reserved

Server (Arduino)

#include <ESP8266WiFi.h>

typedef struct _protocol {
  char cmd;
  char val;
  char etc1;
  char etc2;
  char etc3;
} Protocol;

const char AP_SSID[] = "Makecube Drone";
const char AP_PASS[] = "12345678";
const int  SERVER_PORT = 7777;

WiFiServer server(SERVER_PORT);
WiFiClient client;

void setup() 
{
  Serial.begin(115200);

  WiFi.mode(WIFI_AP);
  WiFi.softAP(AP_SSID, AP_PASS);
    
  server.begin();

  Serial.println("*** Connection Info ***");
  Serial.print("SSID : "); Serial.println(AP_SSID);
  Serial.print("PASS : "); Serial.println(AP_PASS);
  Serial.print("IP   : "); Serial.println(WiFi.localIP());
  Serial.print("PORT : "); Serial.println(SERVER_PORT);
  Serial.println("+- Server Ready -+");
}

void loop() 
{
  if (!client) {
    client = server.available();
    if(client) {
      Serial.println("Client Connected");
    }
    return;
  }

  if(client.available() ) {
    Protocol command;
    command.cmd = client.read();
    command.val = client.read();
    command.etc1 = client.read();
    command.etc2 = client.read();
    command.etc3 = client.read();

    doControl(command);
  }
}

void doControl(Protocol cmd) {
  Serial.print("Control : ");
  Serial.print(cmd.cmd);
  Serial.print(":");
  Serial.println((int)cmd.val);

  if(cmd.cmd == 'q' && cmd.val == 0) {
    client.stop();
    Serial.println("Disconnected");
    return;
  }
}

Client (PC : Java)

package in.makecube.drone.controller;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {

 public static void main(String[] args) {
  Controller controller = new Controller();
  controller.setServer("192.168.4.1", 7777);
  controller.connect();

  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  while (true) {
   try {
    String command = br.readLine();
    if ("q".equals(command))
     break;
    controller.send(command);
   } catch (Exception e) {
    e.printStackTrace();
   }
  }

  controller.disconnect();
 }

}

package in.makecube.drone.controller;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class Controller {

 private String serverIP;
 private int port;

 Socket socket;
 InputStream in;
 OutputStream out;
 byte[] chunk;

 public Controller() {
  chunk = new byte[5];
 }

 public void setServer(String address, int port) {
  serverIP = address;
  this.port = port;
 }

 public void connect() {
  try {
   socket = new Socket(serverIP, port);
   in = socket.getInputStream();
   out = socket.getOutputStream();
  } catch (Exception e) {
   e.printStackTrace();
  }
 }

 public void disconnect() {
  send("q0");
  try {
   if (in != null)
    in.close();
   if (out != null)
    out.close();
   if (socket != null)
    socket.close();
  } catch (Exception e) {
   e.printStackTrace();
  }
 }

 public void send(String command) {
  if (socket == null || out == null)
   return;
  if (command == null || command.trim().length() == 0)
   return;

  try {
   chunk[0] = (byte) command.charAt(0);
   try {
    chunk[1] = (byte) Integer.parseInt(command.substring(1));
   } catch (Exception e) {
    chunk[1] = (byte) 0;
   }
   chunk[2] = (byte) 0;
   chunk[3] = (byte) 0;
   chunk[4] = (byte) 0;
   
   out.write(chunk);
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}