【发布时间】：2012-04-19 23:46:39
【问题描述】：
我正在尝试在我的 java 界面中制作应变仪显示数字。
我有应变计电路工作，它将其电压发送到微控制器（PIC16F877A）程序进行模数转换，然后在串行端口上输出数字。如果你有兴趣，这里是代码：
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);
}
这并不完美，因为当我移动应变计时，输出数字不会改变它们应该的方式。如果有人对此有任何想法，将不胜感激。
但我还是继续前进并将这些数字发送到我的 java 程序中。我在网上找到了这个并对其进行了修改以适合我的设计：
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);*/
}
}
它读取的数字范围与前面的代码相同（一个串行端口，所以我无法测试它是否是相同的数字），尽管它有时会给我一些奇怪的数字，比如 .692 而不是 .692，它会说 320 ，那么下一个数字是 43，那么可能只有一个 '.'会出现，但很快就会恢复正常。我认为这是一个缓冲区问题，上面写着“readBuffer = new byte[500]”，我将大小更改为 500（最初是 8），结果稍微好一点。
无论如何，我必须将输出转换为整数才能对其进行一些数学运算，并且作为整数，我可以轻松过滤掉所有奇怪的数据。所以最终，我现在的问题是我会将这些输出数据转换为可用的整数吗？主要问题是我什至不确定它在我的 java 程序中的哪个位置读取串行端口号。我假设变量是 readBuffer，但是当我尝试使用它的地方时，我会遇到错误，通常是类型不匹配。
所以任何帮助都会很棒，谢谢！
【问题讨论】：
标签： java serial-port integer microcontroller