java - 最佳实践——Java串口蓝牙连接 HC-05

Question

目前将 Java 应用程序连接到 HC-05 蓝牙模块 (Arduino) 的最佳实践是什么？Bluecove 还是其他？如果是这样，您是否可以为带有 HC-05 连接的 Bluecove 推荐任何示例？

Answer 1

前段时间我也有同样的疑问。与此同时，我找到了一种通过 Java 与我的 HC-05 通信的方法。我正在使用 blueCove - 也许还有其他库，但这对我有用。这是我所做的:

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.ServiceRecord;
import javax.bluetooth.UUID;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;

public class HC05 {

    boolean scanFinished = false;
    RemoteDevice hc05device;
    String hc05Url;

    public static void main(String[] args) {
        try {
            new HC05().go();
        } catch (Exception ex) {
            Logger.getLogger(HC05.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    private void go() throws Exception {
        //scan for all devices:
        scanFinished = false;
        LocalDevice.getLocalDevice().getDiscoveryAgent().startInquiry(DiscoveryAgent.GIAC, new DiscoveryListener() {
            @Override
            public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) {
                try {
                    String name = btDevice.getFriendlyName(false);
                    System.out.format("%s (%s)\n", name, btDevice.getBluetoothAddress());
                    if (name.matches("HC.*")) {
                        hc05device = btDevice;
                        System.out.println("got it!");
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void inquiryCompleted(int discType) {
                scanFinished = true;
            }

            @Override
            public void serviceSearchCompleted(int transID, int respCode) {
            }

            @Override
            public void servicesDiscovered(int transID, ServiceRecord[] servRecord) {
            }
        });
        while (!scanFinished) {
            //this is easier to understand (for me) as the thread stuff examples from bluecove
            Thread.sleep(500);
        }

        //search for services:
        UUID uuid = new UUID(0x1101); //scan for btspp://... services (as HC-05 offers it)
        UUID[] searchUuidSet = new UUID[]{uuid};
        int[] attrIDs = new int[]{
            0x0100 // service name
        };
        scanFinished = false;
        LocalDevice.getLocalDevice().getDiscoveryAgent().searchServices(attrIDs, searchUuidSet,
                hc05device, new DiscoveryListener() {
                    @Override
                    public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) {
                    }

                    @Override
                    public void inquiryCompleted(int discType) {
                    }

                    @Override
                    public void serviceSearchCompleted(int transID, int respCode) {
                        scanFinished = true;
                    }

                    @Override
                    public void servicesDiscovered(int transID, ServiceRecord[] servRecord) {
                        for (int i = 0; i < servRecord.length; i++) {
                            hc05Url = servRecord[i].getConnectionURL(ServiceRecord.NOAUTHENTICATE_NOENCRYPT, false);
                            if (hc05Url != null) {
                                break; //take the first one
                            }
                        }
                    }
                });

        while (!scanFinished) {
            Thread.sleep(500);
        }

        System.out.println(hc05device.getBluetoothAddress());
        System.out.println(hc05Url);

        //if you know your hc05Url this is all you need:
        StreamConnection streamConnection = (StreamConnection) Connector.open(hc05Url);
        OutputStream os = streamConnection.openOutputStream();
        InputStream is = streamConnection.openInputStream();

        os.write("1".getBytes()); //just send '1' to the device
        os.close();
        is.close();
        streamConnection.close();
    }
}

在我的环境中，还有一些其他可用的设备，但我过滤了 HC.* 的结果。这是 NetBeans 的控制台输出:

run:
BlueCove version 2.1.0 on winsock
HC-05 (98D331FD157C)
got it!
Nintendo RVL-blabla(00000000FFFF)
GT-N7100 (00000000EEEE)
98D399999999
btspp://98D399999999:1;authenticate=false;encrypt=false;master=false
BlueCove stack shutdown completed
BUILD SUCCESSFUL (total time: 14 seconds)

一旦您知道 HC-05 的 URL (btspp://...)，您就可以在不扫描所有设备和搜索服务的情况下进行连接。这要快得多，代码也减少到几行。

这是我的 arduino 代码，用于处理数据:发送“1”时打开电路板 LED(引脚 13)，发送“0”时关闭:

/*
 * Bluetooth-Modul anschliessen: +5, GND, 
 * Tx an Arduino Rx(Pin 0)
 * Rx an Arduino Tx(Pin 1)
 * 
 * Per Handy mit App 'ArduDroid by Techbitar':
 * -Menü 'Connect me to a Bluetooth device
 * -Send Data "A" oder "B" schaltet die LED auf Pin 13 aus bzw. an
 * und gibt Rückmeldung 'LED:on' oder 'LEF:off'.
 * 
 * https://www.youtube.com/watch?v=sXs7S048eIo
 * 
 * Alternativ mit JavaCode: projekt 'MrBlue'
 */

int ledPin = 13;
int cmd = -1;
int flag = 0;

void setup() {
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  Serial.begin(9600);
}

void loop() {
  if (Serial.available() > 0) {
    cmd = Serial.read();
    flag = 1;
  }

  if (flag == 1) {
    if (cmd == '0') {
      digitalWrite(ledPin, LOW);
      Serial.println("LED: off");
    } else if (cmd == '1') {
      digitalWrite(ledPin, HIGH);
      Serial.println("LED: on");
    } else {
      Serial.print("unknown command: ");
      Serial.write(cmd);
      Serial.print(" (");
      Serial.print(cmd, DEC);
      Serial.print(")");

      Serial.println();
    }

    flag = 0;    
    cmd = 65;
  }

  Serial.flush();
  delay(100);
}

这是我和我的 HC-05 之间的奇特协议(protocol):

我的 Arduino Uno 和 HC-05 之间的连接: