DriveTrain Code

// Main thing to edit is the config.setPort() to the actual port number.
import edu.wpi.first.wpilibj2.command.CommandBase;
import com.corundumstudio.socketio.*;

public class RobotControl {

    public static void main(String[] args) {
        // Initialize GPIO
        GpioController gpio = GpioFactory.getInstance();
        GpioPinDigitalOutput motor1 = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_01);
        GpioPinDigitalOutput motor2 = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_02);

        // Initialize Socket.IO
        Configuration config = new Configuration();
        config.setHostname("your_server_address");
        config.setPort(9092); // Change this to the server's port

        final SocketIOServer server = new SocketIOServer(config);

        server.addConnectListener(new ConnectListener() {
            @Override
            public void onConnect(SocketIOClient client) {
                System.out.println("Connected to client");
            }
        });

        server.addDisconnectListener(new DisconnectListener() {
            @Override
            public void onDisconnect(SocketIOClient client) {
                System.out.println("Disconnected from client");
            }
        });
        // This part of the code is an event listener in Java that waits for incoming messages 
        //labeled with the  event name "control". When a message with this event label
        // is received from a connected Socket.IO client, it triggers the onData method to execute.
        server.addEventListener("control", String.class, new DataListener<String>() {
            @Override
            public void onData(SocketIOClient client, String command, AckRequest ackRequest) {
                switch (command) {
                    case "forward":
                        motor1.high();
                        motor2.high();
                        break;
                    case "backward":
                        motor1.low();
                        motor2.low();
                        break;
                    case "left":
                        motor1.low();
                        motor2.high();
                        break;
                    case "right":
                        motor1.high();
                        motor2.low();
                        break;
                    case "stop":
                        motor1.low();
                        motor2.low();
                        break;
                    default:
                        System.out.println("Invalid command");
                }
            }
        });

        server.start();

        // Keep the program running
        try {
            Thread.sleep(Integer.MAX_VALUE);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        // Clean up GPIO on program exit
        gpio.shutdown();
    }
}

Additionally, the code also includes Socket.IO functionality, which allows the Raspberry Pi to communicate with a server over a WebSocket connection. This means that we can control the robot remotely through a web application or any client that can communicate with the Socket.IO server. Onceall the necessary libararies(Pi4J and java-socketio) is installed we will be able to run this code on the raspberry pi. We will also need to connect the motors to the GPIO pins specified in the code. Once everything is set up, you can execute the Java code on your Raspberry Pi, and it should work as a Wi-Fi controlled robot.

DriveTrain Code • 5 min read

Description