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我想在我的java界面中製作應變計顯示數字。Java - 將串行端口字節數組轉換爲Int？
我有應變計電路工作，並將其電壓送入微控制器（PIC16F877A）程序進行模數轉換，然後在串口輸出數字。如果你有興趣，這裏是代碼：
unsigned short analog; //Variable for analog voltage
long tlong;
unsigned char ch; //
void main() {
USART_Init(19200); //set baude rate
ADCON1 = 0; //All PORTA pins as analog, VDD as Vref
TRISA = 0xFF; //All PORTA is input
do {
analog = ADC_Read(2) >> 2; //Read 10-bit ADC from AN2 and discard 2 LS bit
tlong = (long)analog * 5000; // Convert the result in millivolts
tlong = tlong/1023; // 0..1023 -> 0-5000mV
ch = tlong/1000; // Extract volts (thousands of millivolts) from result
USART_Write(48+ch); // Write result in ASCII format
USART_Write('.');
ch = (tlong/100) % 10; // Extract hundreds of millivolts
USART_Write(48+ch); // Write result in ASCII format
ch = (tlong/10) % 10; // Extract tens of millivolts
USART_Write(48+ch); // Write result in ASCII format
ch = tlong % 10; // Extract digits for millivolts
USART_Write(48+ch); // Write result in ASCII format
USART_Write(' ');
USART_Write(' ');
USART_Write(' ');
Delay_ms(1000);
} while (1);
}
這並不完美，因爲我動應變計，輸出數字不改變，他們應該的樣子。如果任何人有任何想法，它將非常感激。
但無論如何，我將這些數字發送到我的Java程序。我發現這個網上，並修改它適合我的設計：
import java.io.*;
import java.util.*;
import gnu.io.*;
public class SimpleRead implements Runnable, SerialPortEventListener {
static CommPortIdentifier portId;
static Enumeration portList;
InputStream inputStream;
SerialPort serialPort;
Thread readThread;
static byte[] readBuffer;
public static int result2;
public static void main(String[] args) {
portList = CommPortIdentifier.getPortIdentifiers();
System.out.println("portList... " + portList);
while (portList.hasMoreElements()) {
portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
System.out.println("port identified is Serial.. "
+ portId.getPortType());
if (portId.getName().equals("COM4")) {
System.out.println("port identified is COM4.. "
+ portId.getName());
// if (portId.getName().equals("/dev/term/a")) {
SimpleRead reader = new SimpleRead();
} else {
System.out.println("unable to open port");
}
}
}
}
public SimpleRead() {
try {
System.out.println("In SimpleRead() contructor");
serialPort = (SerialPort) portId.open("SimpleReadApp1111",500);
System.out.println(" Serial Port.. " + serialPort);
} catch (PortInUseException e) {
System.out.println("Port in use Exception");
}
try {
inputStream = serialPort.getInputStream();
System.out.println(" Input Stream... " + inputStream);
} catch (IOException e) {
System.out.println("IO Exception");
}
try {
serialPort.addEventListener(this);
} catch (TooManyListenersException e) {
System.out.println("Tooo many Listener exception");
}
serialPort.notifyOnDataAvailable(true);
try {
serialPort.setSerialPortParams(19200, SerialPort.DATABITS_8,
SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
// no handshaking or other flow control
serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_NONE);
// timer on any read of the serial port
serialPort.enableReceiveTimeout(500);
System.out.println("................");
} catch (UnsupportedCommOperationException e) {
System.out.println("UnSupported comm operation");
}
readThread = new Thread(this);
readThread.start();
}
public void run() {
try {
System.out.println("In run() function ");
Thread.sleep(500);
// System.out.println();
} catch (InterruptedException e) {
System.out.println("Interrupted Exception in run() method");
}
}
public void serialEvent(SerialPortEvent event) {
// System.out.println("In Serial Event function().. " + event +
// event.getEventType());
switch (event.getEventType()) {
/*
* case SerialPortEvent.BI: case SerialPortEvent.OE: case
* SerialPortEvent.FE: case SerialPortEvent.PE: case SerialPortEvent.CD:
* case SerialPortEvent.CTS: case SerialPortEvent.DSR: case
* SerialPortEvent.RI: case SerialPortEvent.OUTPUT_BUFFER_EMPTY: break;
*/
case SerialPortEvent.DATA_AVAILABLE:
readBuffer = new byte[500];
try {
while (inputStream.available()>0) {
int numBytes = inputStream.read(readBuffer);
// System.out.println("Number of bytes read " + numBytes);
System.out.print(new String(readBuffer));
}
} catch (IOException e) {
System.out.println("IO Exception in SerialEvent()");
}
break;
}
// System.out.println();
/* String one = new String(readBuffer);
char two = one.charAt(0);
System.out.println("Character at three: " + two);*/
}
}
它讀取同一範圍內的數字（一個串口，所以如果這是同樣的數字我不能測試）爲前面的代碼，雖然它有時會給我奇怪的數字，而不是.692，它會說320，然後下一個數字是43，那麼可能只是'。'。會出現，但很快就會恢復正常。我認爲這是一個緩衝區問題，它表示「readBuffer = new byte [500]」，其中我將大小更改爲500（最初爲8），並且稍微好一些。
我必須把輸出轉換成一個整數來與它做一些數學運算，作爲一個整數，我可以很容易地過濾出所有奇怪的數據。所以最終，我的問題是現在我會把這個輸出數據變成可用的整數嗎？主要的問題是我甚至不知道在我的Java程序中讀取串口號碼的位置。我假設這個變量是readBuffer，但是當我嘗試使用它時，我會遇到錯誤，通常是類型不匹配。
所以任何幫助將是偉大的，謝謝！
這正是流應該是，通常它輸出0.200-1.000，但就像我說的，我偶爾自己變得怪異整數，甚至是小數。非常感謝你的建議，明天我會試着實現inputstreamreader！ – 2012-04-20 01:31:33