Android蓝牙串口通信控制Arduino全彩呼吸灯

这是我期末的时候做的一个Arduino课程设计，可以通过手机APP来控制呼吸灯亮灭及颜色变化。

主要实验器材：

• Arduino UNO开发板
• 共阳三色雾状LED灯
• 面包板、普通LED灯、电阻、杜邦线若干
• HC-05蓝牙模块
• 支持蓝牙功能的Android手机

系统连接图.png

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HC-05蓝牙模块与Arduino连接方式

HC-05 VCC ----- Arduino VIN
HC-05 GND ----- Arduino GND
HC-05 TXD ----- Arduino RXD
HC-05 RXD ----- Arduino TXD

Android蓝牙模块

手机APP连接上HC-05后，在TextView中输入要发送的字符串，定义s、c、f、b分别为小LED灯开、关、和三色彩灯的开、关；通过蓝牙串口将字符串发送出去。

Android蓝牙通信程序关键代码

1. 打开蓝牙：

// 获取蓝牙适配器
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

//请求开启蓝牙
if (!mBluetoothAdapter.isEnabled()) {
    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}

2. 搜索设备：

// 将已配对的设备添加到列表中
Set pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
    for (BluetoothDevice device : pairedDevices) {
        mDevicesArray.add(device.getName() + "\n" + device.getAddress());
        deviceList.add(device);
    }
}
// 注册广播接收器，以获取蓝牙设备搜索结果
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy
// 搜索蓝牙设备
mBluetoothAdapter.startDiscovery();

// Create a BroadcastReceiver for ACTION_FOUND
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        // When discovery finds a device
        if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            // Get the BluetoothDevice object from the Intent
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            deviceList.add(device);
            // Add the name and address to an array adapter to show in a ListView
            mDevicesArray.add(device.getName() + "\n" + device.getAddress());
            // Notify ListView to update
            devicesListAdapter.notifyDataSetChanged();
        }
    }
};

3. 匹配并建立连接

BluetoothSocket socket = null;
try {
    // 蓝牙串口服务对应的UUID。如使用的是其它蓝牙服务，需更改下面的字符串
    UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
    socket = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (Exception e) {
    Log.d("log", "获取Socket失败");
    return;
}
try {
    // Connect the device through the socket. This will block
    // until it succeeds or throws an exception
    socket.connect();
    Log.d("log", "连接成功");
} catch (IOException connectException) {
    // Unable to connect; close the socket and get out
    Log.d("log", "连接失败");
    try {
        socket.close();
    } catch (IOException closeException) { }
    return;
}

4. 收发数据

mmInStream = socket.getInputStream();
mmOutStream = socket.getOutputStream();

//接收数据
byte[] buffer = new byte[1024];
try {
    bytes = mmInStream.read(buffer);
} catch (IOException e) {
    break;
}

//发送数据
try {
    mmOutStream.write(bytes);
} catch (IOException e) { }

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共阳三色雾状LED灯介绍

三色灯.png

顾名思义它可以产生三种颜色，分别是红、绿、蓝，也可以同时调整三种颜色的亮度，产生彩色呼吸灯的效果。

系统原理图：

系统原理图.png

Arduino源码：

#define small_led 8   //Pin 8 连接上小led灯正极
#define led_red 9     //Pin 9 连接上 led的红色引脚
#define led_green 10  //Pin 10 连接上 led的绿色引脚
#define led_blue 11   //Pin 11 连接上 led的蓝色引脚


void setup() {
  Serial.begin(9600);           //设置波特率9600
  pinMode(small_led, OUTPUT);   //设置为输出模式
  pinMode(led_red, OUTPUT); 
  pinMode(led_green, OUTPUT);
  pinMode(led_blue, OUTPUT);

  analogWrite(small_led, 0);    //首先，先把所有的灯都关闭
  analogWrite(led_red, 255);    
  analogWrite(led_green, 255);  //可以随意设置开启关闭哪些灯，搭配出不同组合有不同颜色
  analogWrite(led_blue, 255);
}

void loop() {
  if (Serial.available() > 0)
  {
    char data = Serial.read();
    switch (data)
    {
      case 's': analogWrite(small_led, 255); break;  //小灯亮
      case 'c': analogWrite(small_led, 0); break;  //小灯灭
      case 'f':
        for (int i = 200; i > 0; i--)   //渐亮
        {
          analogWrite(led_red, i);      //慢慢开启红色和绿色会搭配出黄色
          analogWrite(led_green, i);
          analogWrite(led_blue, 255);
          delay(10);
        }

        for (int i = 0; i < 200; i++)   //渐灭
        {
          analogWrite(led_red, 255);    //慢慢关闭绿色和蓝色会搭配出较鲜艳的蓝色
          analogWrite(led_green, i);
          analogWrite(led_blue, i);
          delay(10);
        }
        break;
      case 'b':
        analogWrite(led_red, 255);    //关闭呼吸灯
        analogWrite(led_green, 255);
        analogWrite(led_blue, 255);
        break;
    }
    Serial.println(data);
  }
  delay(10);
}

实际连接图：

实际连接图.png

注意事项：

• 防止LED灯被烧坏，在接5v电源的同时接上220Ω电阻。
• 在烧录代码的时候要把Arduino的TXD、RXD与HC-05的RXD、TXD断开连接，否则会有干扰，代码烧录不进去。

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