Java Program Stops Midway when Reading Com Port of Arduino

Question

I have written a Java program to read a COM port and get data from Arduino UNO, but it only runs for a limited number of times and stops unexpectedly.

I am using this jSerialComm library . The program is as below:

import com.fazecast.jSerialComm.*;
import javax.swing.*;
import java.util.Scanner;

/**
 *
 * @author Lumbani
 */
public class SmartFarm {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        SerialPort ports[] = SerialPort.getCommPorts();

        System.out.println("Select a port:");

        int i=1;
        for(SerialPort port : ports){
            System.out.println(i++ +": "+port.getSystemPortName());
        }

        Scanner s = new Scanner(System.in);
        int choiceport= s.nextInt();

        SerialPort port = ports[choiceport - 1];

        if(port.openPort()){
            System.out.println("Successfully opened port");
        }
        else{ 
            System.out.println("Unable to open the port");
            }
        port.setComPortTimeouts(SerialPort.TIMEOUT_READ_SEMI_BLOCKING,100,0);

        Scanner data = new Scanner(port.getInputStream());

        int line =1;

        while(data.hasNextLine()){
            int number = 0;

            try {number = Integer.parseInt(data.nextLine());
            line++;  
            System.out.println("Line "+ line +": "+number);  
            }
                catch(Exception e){System.out.println("Failed to get data");};

        }
        System.out.println("System run finished");
        }
        }

It stops after running, on average, serial input of 40-50 lines. Please assist me.

It's probably blocked waiting for more data. What is the delimiter it is using? — Shane Wealti
The data comes nonstop from the arduino. I tried writing a similar program in python, and it reads and print non stop. However I need it in Java, which unfortunately is not sustaining the reading process. — pupani3

user9092038 user9092038 · Accepted Answer · 2017-12-13T04:34:58

Try this, in the line

port.setComPortTimeouts(SerialPort.TIMEOUT_READ_SEMI_BLOCKING,100,0);

Use TIMEOUT_SCANNER instead of TIMEOUT_READ_SEMI_BLOCKING. I had the same problem. This solution was presented in the comments section of the youtube video where this code was shown.

Java Program Stops Midway when Reading Com Port of Arduino

1 Answers