public boolean sendData(byte[] data) { if (cvWrite != null && data != null && data.length > 0) { cvWrite.setValue(data); bleGatt.writeCharacteristic(cvWrite); return true; } return false; }
时间: 2024-02-10 14:35:25 浏览: 31
这段代码的作用是什么?
这段代码用于向 BLE 设备发送数据。具体来说,该方法首先判断 `cvWrite` 是否为 null,以及 `data` 是否为空或长度为 0。如果 `cvWrite` 不为 null,且 `data` 不为空且长度大于 0,则将 `data` 写入 `cvWrite` 特征,并通过 `writeCharacteristic` 方法向 BLE 设备发送数据。最后,返回 true 表示发送成功。如果 `cvWrite` 为 null,或者 `data` 为空或长度为 0,则返回 false 表示发送失败。
其中,`cvWrite` 是一个 BluetoothGattCharacteristic 对象,用于表示 BLE 设备的写特征。`setValue` 方法用于设置 `cvWrite` 特征的值。`writeCharacteristic` 方法用于向 BLE 设备发送数据。
总体来说,这段代码实现了向 BLE 设备发送数据的功能。
相关问题
python android 串口通信源码
以下是一个简单的Python与Android串口通信的示例代码:
Python端代码:
```python
import serial
ser = serial.Serial('/dev/ttyUSB0', 9600, timeout=1) # 打开串口
while True:
data = ser.readline().decode('utf-8').strip() # 读取串口数据
if data:
print(data) # 处理数据
ser.close() # 关闭串口
```
Android端代码:
```java
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android_serialport_api.SerialPort;
public class SerialPortManager {
private static final String TAG = "SerialPortManager";
private SerialPort mSerialPort;
private OutputStream mOutputStream;
private InputStream mInputStream;
private ReadThread mReadThread;
private OnDataReceiveListener mOnDataReceiveListener;
private boolean isStop = false;
private static SerialPortManager instance;
public static SerialPortManager getInstance() {
if (instance == null) {
synchronized (SerialPortManager.class) {
if (instance == null) {
instance = new SerialPortManager();
}
}
}
return instance;
}
public void openSerialPort(String path, int baudRate) {
try {
mSerialPort = new SerialPort(path, baudRate, 0);
mOutputStream = mSerialPort.getOutputStream();
mInputStream = mSerialPort.getInputStream();
mReadThread = new ReadThread();
mReadThread.start();
} catch (Exception e) {
e.printStackTrace();
}
}
public void closeSerialPort() {
isStop = true;
if (mReadThread != null) {
mReadThread.interrupt();
}
if (mSerialPort != null) {
mSerialPort.close();
mSerialPort = null;
}
if (mOutputStream != null) {
try {
mOutputStream.close();
mOutputStream = null;
} catch (IOException e) {
e.printStackTrace();
}
}
if (mInputStream != null) {
try {
mInputStream.close();
mInputStream = null;
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void send(byte[] data) {
try {
if (mOutputStream != null) {
mOutputStream.write(data);
}
} catch (IOException e) {
e.printStackTrace();
}
}
public void setOnDataReceiveListener(OnDataReceiveListener listener) {
mOnDataReceiveListener = listener;
}
public interface OnDataReceiveListener {
void onDataReceive(byte[] buffer, int size);
}
private class ReadThread extends Thread {
@Override
public void run() {
super.run();
while (!isStop && !isInterrupted()) {
try {
if (mInputStream == null) {
return;
}
byte[] buffer = new byte[1024];
int size = mInputStream.read(buffer);
if (size > 0) {
if (mOnDataReceiveListener != null) {
mOnDataReceiveListener.onDataReceive(buffer, size);
}
}
} catch (IOException e) {
e.printStackTrace();
return;
}
}
}
}
}
```
在Android应用程序中,你可以使用以下代码来使用SerialPortManager:
```java
SerialPortManager.getInstance().openSerialPort(path, baudRate);
SerialPortManager.getInstance().setOnDataReceiveListener(new SerialPortManager.OnDataReceiveListener() {
@Override
public void onDataReceive(byte[] buffer, int size) {
// 处理数据
}
});
SerialPortManager.getInstance().send(data);
SerialPortManager.getInstance().closeSerialPort();
```
其中,path是串口设备的路径,baudRate是波特率,data是要发送的数据。注意,Android应用程序需要获取串口设备的读写权限。
android 串口收到的没有规则的数据 组成一包完整的数据 代码示例
处理没有规律的数据并组成一包完整的数据的过程通常称为“数据帧同步”。以下是一个处理串口数据的示例代码:
```
public class SerialPortUtil {
private SerialPort mSerialPort;
private OutputStream mOutputStream;
private InputStream mInputStream;
private ReadThread mReadThread;
private OnDataReceiveListener onDataReceiveListener = null;
private boolean isStop = false;
public SerialPortUtil() {
try {
mSerialPort = new SerialPort(new File("/dev/ttyS1"), 9600, 0);
mOutputStream = mSerialPort.getOutputStream();
mInputStream = mSerialPort.getInputStream();
mReadThread = new ReadThread();
isStop = false;
mReadThread.start();
} catch (IOException e) {
e.printStackTrace();
}
}
public void send(String data) {
try {
mOutputStream.write(data.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
}
public void setOnDataReceiveListener(OnDataReceiveListener dataReceiveListener) {
onDataReceiveListener = dataReceiveListener;
}
public void closeSerialPort() {
isStop = true;
if (mReadThread != null) {
mReadThread.interrupt();
mReadThread = null;
}
if (mSerialPort != null) {
mSerialPort.close();
mSerialPort = null;
}
}
public interface OnDataReceiveListener {
void onDataReceive(String data);
}
private class ReadThread extends Thread {
@Override
public void run() {
super.run();
while (!isStop && !isInterrupted()) {
int size;
try {
byte[] buffer = new byte[64];
if (mInputStream == null) return;
size = mInputStream.read(buffer);
if (size > 0) {
onDataReceiveListener.onDataReceive(new String(buffer, 0, size));
}
} catch (IOException e) {
e.printStackTrace();
return;
}
}
}
}
}
```
在这个示例中,我们创建了一个 `SerialPortUtil` 类,用于发送和接收串口数据。我们可以通过调用 `send()` 方法向串口发送数据,并通过 `setOnDataReceiveListener()` 方法设置接收数据的监听器。当收到数据时,我们将调用 `onDataReceive()` 方法,将收到的数据传递给监听器。
在 `ReadThread` 中,我们使用一个 `buffer` 数组来存储接收到的数据。当收到数据时,我们将数据转换成字符串,并将其传递给监听器。但是,如果数据没有规律,我们需要在 `ReadThread` 中添加更多的逻辑来处理数据帧同步。例如,我们可以使用一个缓冲区来存储收到的数据,并在接收到完整的数据包时,将其传递给监听器。