Serial Connections with Ardulink-2

Serial over USB is the most common way to connect Arduino boards. Ardulink-2 provides three serial link adapters based on different Java serial libraries.

Which Serial Adapter to Choose

Adapter Maven Artifact Pros Cons
JSSC ardulink-link-serial-jssc Pure Java, no native deps, actively maintained Fewer platform quirks
NRSerialRxTx ardulink-link-serial-nrrxtx Good cross-platform support Less commonly used
Rxtx ardulink-link-serial-rxtx Legacy compatibility Unmaintained upstream

Recommendation: Use ardulink-link-serial-jssc unless you have a specific reason to choose another.

Setup

Maven 

<dependency>
    <groupId>org.ardulink</groupId>
    <artifactId>ardulink-core-base</artifactId>
    <version>2.3.1</version>
</dependency>
<dependency>
    <groupId>org.ardulink</groupId>
    <artifactId>ardulink-link-serial-jssc</artifactId>
    <version>2.3.1</version>
</dependency>

Gradle 

implementation 'org.ardulink:ardulink-core-base:2.3.1'
implementation 'org.ardulink:ardulink-link-serial-jssc:2.3.1'

Connecting 

import org.ardulink.core.Link;
import org.ardulink.core.pin.Pin;
import org.ardulink.core.convenience.Links;

public class SerialExample {
    public static void main(String... args) throws Exception {
        try (Link link = Links.getDefault()) {
            // The adapter auto-discovers the serial port
            link.switchDigitalPin(Pin.digitalPin(13), true);
        }
    }
}

Specifying the Serial Port

If you need to target a specific port, use the connection string:

// Linux
Link link = Links.getLink("ardulink://serial?port=/dev/ttyACM0&baudrate=115200");

// macOS
Link link = Links.getLink("ardulink://serial?port=/dev/cu.usbmodem14201&baudrate=115200");

// Windows
Link link = Links.getLink("ardulink://serial?port=COM3&baudrate=115200");

Finding Your Serial Port

Linux 

ls /dev/ttyACM* /dev/ttyUSB*
# or
ls /dev/serial/by-id/*

macOS 

ls /dev/cu.usbmodem* /dev/cu.usbserial*

Windows

Check Device Manager under Ports (COM & LPT) for your Arduino.

Serial Port Permissions (Linux)

By default, serial ports require root access. Add your user to the dialout group:

sudo usermod -a -G dialout $USER

Log out and back in for the change to take effect.

Baud Rate

The default baud rate for the Ardulink firmware is 115200. This should match between the firmware and the Java connection. You can change it in the connection string:

ardulink://serial?port=/dev/ttyACM0&baudrate=9600

Troubleshooting

Problem Solution
Port not found Check cable, try different USB port, verify driver installed
Permission denied (Linux) Add user to dialout group
Garbage data Baud rate mismatch — ensure both sides use same rate
Connection timeout Wrong port, or firmware not uploaded
Port busy Close Arduino IDE Serial Monitor, or other applications using the port

Next Steps