Android Open Source - smartcar Socket Receive

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Back to project page smartcar.

License

The source code is released under:

GNU General Public License

Java Source Code

package piSockets;
//  w w  w.  j  av a2  s.  c o  m
/**
 * This class gets incomming strings from the socket connection and process them accordingly.
 * Finally puts them on an outgoing list to be sent to the motor driver (arduino).
 * @author Team Pegasus (dimi)
 */

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.util.ArrayList;

public class SocketReceive implements Runnable{
  BufferedReader brInput = null;
//  PrintWriter out = null;
  int direction = 0;
  int degrees = 0; //middle
  int speed = 0;//standard speed
  boolean backwards = false;
  public static ArrayList<byte[]> outputList = new ArrayList<byte[]>();
  Socket piSocket;
  
  public SocketReceive(Socket socket) {
    this.piSocket = socket;


  }

  private void socketProcess(String input) {
    if (!input.contains("#") && !input.contains("$") && !input.contains("!") && !input.contains(":")) {
      /* early version communication protocol */
      boolean validCommand = true;
      if (input.contains("forward")) {
        direction = 1;
        speed = 100;
        backwards = false;
      } else if (input.contains("backward")) {
        direction = -1;
        speed = 100;
        backwards = true;
      } else if (input.contains("stop")) {
        speed = 0;
      } else if (input.contains("left")) {
        if (degrees - 1 >= -89)
          degrees -= 2;
      } else if (input.contains("right")) {
        if (degrees + 1 <= 89)
          degrees += 2;
      } else if (input.contains("middle")) {
        degrees = 0;
      } else {
        System.out.println("Invalid Command");
        validCommand = false;
      }
      if (validCommand) {
        byte[] command = new byte[2];
        if (backwards && speed > 0) {
          speed *= direction;
        }
        command[0] = (byte) speed;
        command[1] = (byte) degrees;
        outputList.add(command);
      }
    }else if(input.contains("!") && input.contains(":")){
      /* tank STABLE version */
      String left = "", right = "";
      boolean leftMode = false, rightMode = false;
      for (int i=0;i<input.length();i++){
        
        if (leftMode && input.charAt(i) != ':'){
          left += input.charAt(i);
        }
        
        if (rightMode && input.charAt(i) != '!'){
          right += input.charAt(i);
        }
        
        if (input.charAt(i) == ':'){
          leftMode = false;
          rightMode = true;
        }
        
        if (input.charAt(i) == '!'){
          leftMode = true;
          rightMode = false;
        }


      }
      byte[] command = new byte[2];
      if (!input.contains("*")) {
        //when input comes from the java joystick
        int leftValue = Integer.parseInt(left);
        int rightValue = Integer.parseInt(right);
        command[0] = (byte) leftValue;
        command[1] = (byte) rightValue;
      }else{
        //this happens when input is UNSCALED, from the android app
        right = right.replace("*", "");
        int[] temp = rawJoystickInput(Integer.parseInt(left),Integer.parseInt(right));
    //    System.out.println("left: " + temp[0] + " right: " + temp[1]);
        command[0] = (byte) temp[0];
        command[1] = (byte) temp[1];
      }
      outputList.add(command);
    }else if(input.contains("#") && input.contains("$")){
      /* joystick version WITH STEERING WHEEL */
      String velocity = "", angle = "";
      boolean speedMode = false, angleMode = false;
      for (int i=0;i<input.length();i++){
        
        if (angleMode && input.charAt(i) != '$'){
          angle += input.charAt(i);
        }
        
        if (speedMode && input.charAt(i) != '#'){
          velocity += input.charAt(i);
        }
        
        if (input.charAt(i) == '#'){
          angleMode = true;
          speedMode = false;
        }
        if (input.charAt(i) == '$'){
          speedMode = true;
          angleMode = false;
        }

      }
      int speedValue = Integer.parseInt(velocity);
      int angleValue = Integer.parseInt(angle);
      byte[] command = new byte[2];
      command[0] = (byte) speedValue;
      command[1] = (byte) angleValue;
      outputList.add(command);
//      System.out.println("Speed: " + speedValue + " Angle: " + angleValue);
          
    }
  }
  /* a FIFO structure to handle the outbound commands */
  public byte[] SocketIO(){
    byte [] serialOut = outputList.get(0);
    outputList.remove(0);
    return serialOut;
  }

  @Override
  public void run() {
    System.out.println("listening to input");

    try {
      //you can use a printWriter to send stuff while receiving them, maybe to create
      //a handshake protocol?
      
  //    out = new PrintWriter(piSocket.getOutputStream(), true);
      InputStreamReader InputReader = new InputStreamReader((piSocket.getInputStream()));
      brInput = new BufferedReader(InputReader);
      String input;
      while ((input = brInput.readLine()) != null) {
//        System.out.println("input" + input);
        socketProcess(input);    
      }    
      InputReader.close();
      piSocket.close();      
      System.out.println("Socket closed");

    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }    
  }
  /* this happens when the input is unscaled and not ready to be sent to the motors in "tank" mode */
  private int[] rawJoystickInput(int angle, int speed) {
  //  System.out.println("angle: " + angle + " speed: " + speed);
    double scale = 8.0; // how sensitive it is. depends on your power source
    speed = (int) Math.round((speed * scale) / 100.0);
    float rel = (float) ((angle * scale) / 90.0) ;
    rel = Math.round(rel);
    rel = (int) scale-Math.abs(rel);
    float sideSpeed = Math.round((float) ((rel/scale) * speed));
    int[] motorsOut = new int[2];
      if (angle>0){
        motorsOut[0] = speed;  
        motorsOut[1] = (int) sideSpeed;
      }else{
        motorsOut[0] = (int) sideSpeed;
        motorsOut[1] = speed;
      }
    if (motorsOut[0] == speed && motorsOut[1] == 0) motorsOut[1] = -speed;
    if (motorsOut[1] == speed && motorsOut[0] == 0) motorsOut[0] = -speed;
    
  //  System.out.println("left speed: " + motorsOut[0] + " right speed: " + motorsOut[1]);

    return motorsOut;
  }

}

Java Source Code List

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