Я следую простому примеру found here (example one), чтобы иметь ардуино, подключенный к малине Pi, и прочитать некоторые данные из arduino на Pi в Java.Arduino Java SerialEvent не называется
Проблема в том, что метод SerialEvent никогда не вызывается, что означает, что данные не поступают. Однако, когда я открываю последовательный монитор, я вижу, что данные читаются правильно.
Правильный последовательный порт также используется.
Вот код Java.
//This class:
// - Starts up the communication with the Arduino.
// - Reads the data coming in from the Arduino and
// converts that data in to a useful form.
// - Closes communication with the Arduino.
//Code builds upon this great example:
//http://www.csc.kth.se/utbildning/kth/kurser/DH2400/interak06/SerialWork.java
//The addition being the conversion from incoming characters to numbers.
//Load Libraries
import java.io.*;
import java.util.TooManyListenersException;
//Load RXTX Library
import gnu.io.*;
class ArduinoComm implements SerialPortEventListener
{
//Used to in the process of converting the read in characters-
//-first in to a string and then into a number.
String rawStr="";
//Declare serial port variable
SerialPort mySerialPort;
//Declare input steam
InputStream in;
boolean stop=false;
public void start(String portName,int baudRate)
{
stop=false;
try
{
//Finds and opens the port
CommPortIdentifier portId = CommPortIdentifier.getPortIdentifier(portName);
mySerialPort = (SerialPort)portId.open("my_java_serial" + portName, 2000);
System.out.println("Serial port found and opened");
//configure the port
try
{
mySerialPort.setSerialPortParams(baudRate,
mySerialPort.DATABITS_8,
mySerialPort.STOPBITS_1,
mySerialPort.PARITY_NONE);
System.out.println("Serial port params set: "+baudRate);
}
catch (UnsupportedCommOperationException e)
{
System.out.println("Probably an unsupported Speed");
}
//establish stream for reading from the port
try
{
in = mySerialPort.getInputStream();
}
catch (IOException e)
{
System.out.println("couldn't get streams");
}
// we could read from "in" in a separate thread, but the API gives us events
try
{
mySerialPort.addEventListener(this);
mySerialPort.notifyOnDataAvailable(true);
System.out.println("Event listener added");
}
catch (TooManyListenersException e)
{
System.out.println("couldn't add listener");
}
}
catch (Exception e)
{
System.out.println("Port in Use: "+e);
}
}
//Used to close the serial port
public void closeSerialPort()
{
try
{
in.close();
stop=true;
mySerialPort.close();
System.out.println("Serial port closed");
}
catch (Exception e)
{
System.out.println(e);
}
}
//Reads the incoming data packets from Arduino.
public void serialEvent(SerialPortEvent event)
{
//Reads in data while data is available
while (event.getEventType()== SerialPortEvent.DATA_AVAILABLE && stop==false)
{
try
{
//-------------------------------------------------------------------
//Read in the available character
char ch = (char)in.read();
//If the read character is a letter this means that we have found an identifier.
if (Character.isLetter(ch)==true && rawStr!="")
{
//Convert the string containing all the characters since the last identifier into an integer
int value = Integer.parseInt(rawStr);
if (ch=='A')
{
System.out.println("Value A is: "+value);
}
if (ch=='B')
{
System.out.println("Value B is: "+value);
}
//Reset rawStr ready for the next reading
rawStr = ("");
}
else
{
//Add incoming characters to a string.
//Only add characters to the string if they are digits.
//When the arduino starts up the first characters it sends through are S-t-a-r-t-
//and so to avoid adding these characters we only add characters if they are digits.
if (Character.isDigit(ch))
{
rawStr = (rawStr + Character.toString(ch));
}
else
{
System.out.print(ch);
}
}
}
catch (IOException e)
{
}
}
}
}
А вот Arduino Sketch
//Ardunio code for Part 01
//First we will define the values to be sent
//Note: The java code to go with this example reads-
//-in integers so values will have to be sent as integers
int valueA = 21;
int valueB = 534;
void setup()
{
Serial.begin(115200);
Serial.println("Start");
}
void loop()
{
//We send the value coupled with an identifier character
//that both marks the end of the value and what the value is.
Serial.print(valueA);
Serial.print("A");
Serial.print(valueB);
Serial.print("B");
//A delay to slow the program down to human pace.
delay(500);
}
Я прочитал, что изменение Serial.print в Serial.write это новый способ сделать это, но изменить это не имело никакого результата.