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POSerial Communication between Java RXTX and Arduino
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  1. POSerial Communication between Java RXTX and Arduino
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    copied!<p>I'm trying to communicate between my PC (Windows 7 using Netbeans and RXTX) with an Arduino Pro, using the serial port. The Arduino is actually connected to the PC using an FTDI cable. </p> <p>The code is based on the Java SimpleRead.Java found <a href="http://java.sun.com/products/javacomm/reference/docs/API_users_guide_3.html" rel="nofollow noreferrer">here.</a></p> <p>Currently the Arduino simply prints out a string when it starts up. My Java program should print the number of bytes that have been read and then print out the contents. The Java program works, sort of... </p> <p>If the string is long (>10 bytes or so) the output will get broken up. </p> <p>So if on the Arduino I print</p> <pre><code>Serial.println("123456789123456789"); //20 bytes including '\r' and '\n' </code></pre> <p>The output of my Java program may look something like:</p> <pre><code>Number of Bytes: 15 1234567891234 Number of Bytes: 5 56789 </code></pre> <p>or</p> <pre><code>Number of Bytes: 12 1234567891 Number of Bytes: 8 23456789 </code></pre> <p>I'm thinking it's a timing problem, because when I manually go through the code using the debugger, the result string is always what it should be: one 20 byte string.</p> <p>I've been messing with various things but I haven't been able to fix the problem.</p> <p>Here is the part of the code that is giving me problems:</p> <pre><code>static int baudrate = 9600, dataBits = SerialPort.DATABITS_8, stopBits = SerialPort.STOPBITS_1, parity = SerialPort.PARITY_NONE; byte[] readBuffer = new byte[128]; ... ... public void serialEvent(SerialPortEvent event) { if (event.getEventType() == SerialPortEvent.DATA_AVAILABLE) { try { if (input.available() &gt; 0) { //Read the InputStream and return the number of bytes read numBytes = input.read(readBuffer); String result = new String(readBuffer,0,numBytes); System.out.println("Number of Bytes: " + numBytes); System.out.println(result); } } catch (IOException e) { System.out.println("Data Available Exception"); } } </code></pre>
 

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