Java串口写/发送ASCII数据

我的问题是我需要通过蓝牙在Java中控制移动机器人E-puck，通过发送命令如“D，100,100”来设置速度，“E”来获得速度等等。我有一些代码：

String command = "D,100,100"; OutputStream mOutputToPort = serialPort.getOutputStream(); mOutputToPort.write(command.getBytes()); 

所以用这种方法write我只能发送byte[]数据，但我的机器人不会理解。 例如，之前我一直在Matlab上使用这样的命令：

 s = serial('COM45'); fopen(s); fprintf(s,'D,100,100','async'); 

或仅限程序Putty类型：

 D,100,100 `enter` 

附加信息：

我也想通了，Matlab有另一个解决方案。

 s = serial('COM45'); fopen(s); data=[typecast(int8('-D'),'int8') typecast(int16(500),'int8') typecast(int16(500),'int8')]; 

在这种情况下：

 data = [ -68 -12 1 -12 1]; fwrite(s,data,'int8','async'); 

在Java中不一样吗：

  byte data[] = new byte[5]; data[0] = -'D'; data[1] = (byte)(500 & 0xFF); data[2] = (byte)(500 >> 8); data[3] = (byte)(500 & 0xFF); data[4] = (byte)(500>> 8); 

然后：

 OutputStream mOutputToPort = serialPort.getOutputStream(); mOutputToPort.write(data); mOutputToPort.flush(); 

Answer 1

代码注释中的主要细节。 现在，您可以通过在命令窗口D,1000,-500键入并按Enter键来更改车轮速度。

 public class serialRobot { public static void main(String[] s) { SerialPort serialPort = null; try { CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier("COM71"); if (portIdentifier.isCurrentlyOwned()) { System.out.println("Port in use!"); } else { System.out.println(portIdentifier.getName()); serialPort = (SerialPort) portIdentifier.open( "ListPortClass", 300); int b = serialPort.getBaudRate(); System.out.println(Integer.toString(b)); serialPort.setSerialPortParams(115200, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); serialPort.setInputBufferSize(65536); serialPort.setOutputBufferSize(4096); System.out.println("Opened " + portIdentifier.getName()); OutputStream mOutputToPort = serialPort.getOutputStream(); InputStream mInputFromPort = serialPort.getInputStream(); PerpetualThread t = readAndPrint(mInputFromPort); inputAndSend(mOutputToPort); t.stopRunning(); mOutputToPort.close(); mInputFromPort.close(); } } catch (IOException ex) { System.out.println("IOException : " + ex.getMessage()); } catch (UnsupportedCommOperationException ex) { System.out.println("UnsupportedCommOperationException : " + ex.getMessage()); } catch (NoSuchPortException ex) { System.out.println("NoSuchPortException : " + ex.getMessage()); } catch (PortInUseException ex) { System.out.println("PortInUseException : " + ex.getMessage()); } finally { if(serialPort != null) { serialPort.close(); } } } private static PerpetualThread readAndPrint(InputStream in) { final BufferedInputStream b = new BufferedInputStream(in); PerpetualThread thread = new PerpetualThread() { @Override public void run() { byte[] data = new byte[16]; int len = 0; for(;isRunning();) { try { len = b.read(data); } catch (IOException e) { e.printStackTrace(); } if(len > 0) { System.out.print(new String(data, 0, len)); } } } }; thread.start(); return thread; } private static void inputAndSend(OutputStream out) { BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); int k = 0; for(;;) { String komanda; try { komanda = in.readLine(); } catch (IOException e) { e.printStackTrace(); return; } komanda = komanda.trim(); if(komanda.equalsIgnoreCase("end")) return; byte komandaSiust[] = proces(komanda); //Command we send after first //connection, it's byte array where 0 member is the letter that describes type of command, next two members // is about left wheel speed, and the last two - right wheel speed. try { if(k == 0){ String siunc = "P,0,0\n"; // This command must be sent first time, when robot is connected, otherwise other commands won't work ByteBuffer bb = ByteBuffer.wrap(siunc.getBytes("UTF-8")); bb.order(ByteOrder.LITTLE_ENDIAN); out.write(bb.array()); out.flush(); }else{ ByteBuffer bb = ByteBuffer.wrap(komandaSiust); bb.order(ByteOrder.LITTLE_ENDIAN); out.write(bb.array()); out.flush(); } k++; } catch (IOException e) { e.printStackTrace(); return; } } } private static byte[] proces(String tekstas){ tekstas = tekstas.trim(); char[] charArray = tekstas.toCharArray(); byte kodas1[]; int fComa = tekstas.indexOf(',', 1); int sComa = tekstas.indexOf(',', 2); int matavimas = charArray.length; int skir1 = sComa - fComa - 1; int skir2 = matavimas - sComa -1; char leftSpeed[] = new char[skir1]; for(int i = 0; i < skir1; i++){ leftSpeed[i] = charArray[fComa + i + 1]; } char rightSpeed[] = new char[skir2]; for(int i = 0; i < skir2; i++){ rightSpeed[i] = charArray[sComa + i + 1]; } String right = String.valueOf(rightSpeed); String left = String.valueOf(leftSpeed); int val1 = Integer.parseInt(left); int val2 = Integer.parseInt(right); kodas1 = new byte[5]; kodas1[0] = (byte)-charArray[0]; kodas1[1] = (byte)(val1 & 0xFF); kodas1[2] = (byte)(val1 >> 8); kodas1[3] = (byte)(val2 & 0xFF); kodas1[4] = (byte)(val2 >> 8); return kodas1; } private static class PerpetualThread extends Thread { private boolean isRunning = true; public boolean isRunning() { return isRunning; } public void stopRunning() { isRunning = false; this.interrupt(); } } } 

Answer 2

根据文档 ，您需要在串行端口上调用setSerialPortParams(int baudrate, int dataBits, int stopBits, int parity) 。