Hi,
I'm creating an Arduino Data Logger/ Multimeter. I'm getting an error in Processing when I try to get serial data from the Arduino.

My Arduino Code:

1. #include <Boards.h>
   #include <Firmata.h>
   
   void setup() {
     // initialize the serial communication:
     Serial.begin(9600);
    
   }
   
   void loop() {
   String A_Data;
   
   A_Data = analogRead(A0);
   A_Data += ",";
   A_Data += analogRead(A1);
   A_Data += ",";
   A_Data += analogRead(A2);
   A_Data += ",";
   A_Data += analogRead(A3);
   A_Data += ",";
   A_Data += analogRead(A4);
   A_Data += ",";
   A_Data += analogRead(A5);
   
   Serial.println(A_Data);
    
     delay(100);
   }

The data coming out of the Arduino, as seen by the "Serial Monitor":

1. 216,217,218,218,215,215
   218,219,219,219,217,215
   214,215,215,216,214,213
   216,217,216,216,214,214
   214,215,215,215,213,212
   214,215,215,215,213,211
   213,214,215,214,213,212
   212,213,213,214,211,210

The Processing Code:

1.  import processing.serial.*;
    
    Serial myPort;        // The serial port
    int xPos = 1;         // horizontal position of the graph
    int chCount = 0;
    String[] ChVa;
    float[] ChVo;
    PFont font;
    
    void setup () {
    // set the window size:
    size(600, 480);       
    
    // List all the available serial ports
    println(Serial.list());
    // I know that the first port in the serial list on my mac
    // is always my  Arduino, so I open Serial.list()[0].
    // Open whatever port is the one you're using.
    myPort = new Serial(this, Serial.list()[0], 9600);
    // don't generate a serialEvent() unless you get a newline character:
    myPort.bufferUntil('\n');
    // set inital background:
    background(0);
    font = loadFont("CenturySchoolbook-32.vlw");
    textFont(font);
    }
    void draw () {
    // everything happens in the serialEvent()
    }
    void serialEvent (Serial myPort)
    {
    
    // get the ASCII string:
    String inString = myPort.readStringUntil('\n');
   
    if (inString != null)
       {
        // trim off any whitespace:
        inString = trim(inString);
          
            //split string into array
            ChVa = split(inString, ',');
           
            //convert string array to integer array and scale
            for (int i = 0; i < 6; i++)
            {
            int tmp = int(ChVa[i]);
            ChVo[i] = tmp*0.0049;
            }
           
            //Display Data
            background(0);
            //text("Ch0 : " + inV + "V",15,30);
            text("Ch0 : " + ChVo[0],15,30);
            text("Ch1 : " + ChVo[1],15,60);
            text("Ch2 : " + ChVo[2],15,90);
            text("Ch3 : " + ChVo[3],15,120);
            text("Ch4 : " + ChVo[4],15,150);
            text("Ch5 : " + ChVo[5],15,180);
           
        
       }   
   }
    
   

And finally the ERROR:

1. Stable Library
   =========================================
   Native lib Version = RXTX-2.1-7
   Java lib Version   = RXTX-2.1-7
   [0] "COM6"
   error, disabling serialEvent() for //./COM6
   java.lang.reflect.InvocationTargetException
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
       at java.lang.reflect.Method.invoke(Method.java:597)
       at processing.serial.Serial.serialEvent(Unknown Source)
       at gnu.io.RXTXPort.sendEvent(RXTXPort.java:732)
       at gnu.io.RXTXPort.eventLoop(Native Method)
       at gnu.io.RXTXPort$MonitorThread.run(RXTXPort.java:1575)
   Caused by: java.lang.NullPointerException
       at _6_Ch_Display.serialEvent(_6_Ch_Display.java:81)
       ... 8 more