Java CAN-Bus Issue

Technical Java
1

We have been having some trouble with the CANJaguars.
I have updated firmware, assigned IDs, and tested motors using BDC-Comm.

The problem lies in running the code. When I enable the robot, I get this:


[cRIO] NI-VISA Server 4.5 started successfully.
[cRIO] task 0xe63670 (t1) deleted: errno=1835009 (0x1c0001) status=1 (0x1)
[cRIO] FPGA Hardware GUID: 0x2EAA5E59CAF1A8A966853A011B61CC91
[cRIO] FPGA Software GUID: 0x2EAA5E59CAF1A8A966853A011B61CC91
[cRIO] FPGA Hardware Version: 2011
[cRIO] FPGA Software Version: 2011
[cRIO] FPGA Hardware Revision: 1.5.3
[cRIO] FPGA Software Revision: 1.5.3
[cRIO] * Loading StartupDlls: FRC_JavaVM
[cRIO] 
[cRIO] 
[cRIO] [OTA Server] Version: 2011 FRC, Jan  6 2011, 09:47:42
[cRIO] 
[cRIO] 
[cRIO] Welcome to LabVIEW Real-Time 8.6.1f3
[cRIO] 
[cRIO] [Squawk VM] Version: 2011 FRC, Jan 17 2011, 16:12:19
[cRIO] 
[cRIO] [Squawk VM] Version: 2011 FRC, Jan 17 2011, 16:12:19
[cRIO] FPGA Hardware GUID: 0x2eaa5e59caf1a8a966853a011b61cc91
[cRIO] FPGA Software GUID: 0x2eaa5e59caf1a8a966853a011b61cc91
[cRIO] edu.wpi.first.wpilibj.can.CANNotInitializedException
[cRIO]     at edu.wpi.first.wpilibj.can.CANExceptionFactory.checkStatus(CANExceptionFactory.java:44)
[cRIO]     at edu.wpi.first.wpilibj.can.JaguarCANDriver.sendMessage(JaguarCANDriver.java:29)
[cRIO]     at edu.wpi.first.wpilibj.CANJaguar.sendMessage(CANJaguar.java:567)
[cRIO]     at edu.wpi.first.wpilibj.CANJaguar.getTransaction(CANJaguar.java:630)
[cRIO]     at edu.wpi.first.wpilibj.CANJaguar.getFirmwareVersion(CANJaguar.java:1192)
[cRIO]     at edu.wpi.first.wpilibj.CANJaguar.initCANJaguar(CANJaguar.java:240)
[cRIO]     at edu.wpi.first.wpilibj.CANJaguar.<init>(CANJaguar.java:267)
[cRIO]     at edu.wpi.first.wpilibj.templates.RobotTemplate.robotInit(RobotTemplate.java:30)
[cRIO]     at edu.wpi.first.wpilibj.IterativeRobot.startCompetition(IterativeRobot.java:73)
[cRIO]     at edu.wpi.first.wpilibj.RobotBase.startApp(RobotBase.java:154)
[cRIO]     in virtual method #10 of javax.microedition.midlet.MIDlet(bci=17)
[cRIO]     at javax.microedition.midlet.MIDletTunnelImpl.callStartApp(64)
[cRIO]     at com.sun.squawk.imp.MIDletMainWrapper.main(110)
[cRIO]     in virtual method #95 of com.sun.squawk.Klass(bci=25)
[cRIO]     at com.sun.squawk.Isolate.run(1506)
[cRIO]     at java.lang.Thread.run(231)
[cRIO]     in virtual method #47 of com.sun.squawk.VMThread(bci=42)
[cRIO]     in static method #3 of com.sun.squawk.VM(bci=6)
[cRIO] Default IterativeRobot.disabledInit() method... Overload me!
[cRIO] Default IterativeRobot.disabledContinuous() method... Overload me!
[cRIO] Default IterativeRobot.disabledPeriodic() method... Overload me!
[cRIO] Default IterativeRobot.teleopInit() method... Overload me!
[cRIO] java.lang.NullPointerException
[cRIO]     at edu.wpi.first.wpilibj.templates.RobotTemplate.teleopPeriodic(RobotTemplate.java:46)
[cRIO]     at edu.wpi.first.wpilibj.IterativeRobot.startCompetition(IterativeRobot.java:141)
[cRIO]     at edu.wpi.first.wpilibj.RobotBase.startApp(RobotBase.java:154)
[cRIO]     in virtual method #10 of javax.microedition.midlet.MIDlet(bci=17)
[cRIO]     at javax.microedition.midlet.MIDletTunnelImpl.callStartApp(64)
[cRIO]     at com.sun.squawk.imp.MIDletMainWrapper.main(110)
[cRIO]     in virtual method #95 of com.sun.squawk.Klass(bci=25)
[cRIO]     at com.sun.squawk.Isolate.run(1506)
[cRIO]     at java.lang.Thread.run(231)
[cRIO]     in virtual method #47 of com.sun.squawk.VMThread(bci=42)
[cRIO]     in static method #3 of com.sun.squawk.VM(bci=6)
[cRIO] Default IterativeRobot.teleopContinuous() method... Overload me!
[cRIO] java.lang.NullPointerException
[cRIO]     at edu.wpi.first.wpilibj.templates.RobotTemplate.teleopPeriodic(RobotTemplate.java:46)
[cRIO]     at edu.wpi.first.wpilibj.IterativeRobot.startCompetition(IterativeRobot.java:141)
[cRIO]     at edu.wpi.first.wpilibj.RobotBase.startApp(RobotBase.java:154)
[cRIO]     in virtual method #10 of javax.microedition.midlet.MIDlet(bci=17)
[cRIO]     at javax.microedition.midlet.MIDletTunnelImpl.callStartApp(64)
[cRIO]     at com.sun.squawk.imp.MIDletMainWrapper.main(110)
[cRIO]     in virtual method #95 of com.sun.squawk.Klass(bci=25)
[cRIO]     at com.sun.squawk.Isolate.run(1506)
[cRIO]     at java.lang.Thread.run(231)
[cRIO]     in virtual method #47 of com.sun.squawk.VMThread(bci=42)
[cRIO]     in static method #3 of com.sun.squawk.VM(bci=6)
[cRIO] java.lang.NullPointerException
[cRIO]     at edu.wpi.first.wpilibj.templates.RobotTemplate.teleopPeriodic(RobotTemplate.java:46)
[cRIO]     at edu.wpi.first.wpilibj.IterativeRobot.startCompetition(IterativeRobot.java:141)
[cRIO]     at edu.wpi.first.wpilibj.RobotBase.startApp(RobotBase.java:154)
[cRIO]     in virtual method #10 of javax.microedition.midlet.MIDlet(bci=17)
[cRIO]     at javax.microedition.midlet.MIDletTunnelImpl.callStartApp(64)
[cRIO]     at com.sun.squawk.imp.MIDletMainWrapper.main(110)
[cRIO]     in virtual method #95 of com.sun.squawk.Klass(bci=25)
[cRIO]     at com.sun.squawk.Isolate.run(1506)
[cRIO]     at java.lang.Thread.run(231)
[cRIO]     in virtual method #47 of com.sun.squawk.VMThread(bci=42)
[cRIO]     in static method #3 of com.sun.squawk.VM(bci=6)

NullPointerException repeats…

Here is my code:


/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008. All Rights Reserved.                             */
/* Open Source Software - may be modified and shared by FRC teams. The code   */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project.                                                               */
/*----------------------------------------------------------------------------*/

package edu.wpi.first.wpilibj.templates;
import edu.wpi.first.wpilibj.IterativeRobot;
import edu.wpi.first.wpilibj.CANJaguar;
import edu.wpi.first.wpilibj.Joystick;
import edu.wpi.first.wpilibj.SpeedController;

/**
 * The VM is configured to automatically run this class, and to call the
 * functions corresponding to each mode, as described in the IterativeRobot
 * documentation. If you change the name of this class or the package after
 * creating this project, you must also update the manifest file in the resource
 * directory.
 */
public class RobotTemplate extends IterativeRobot {
   
    Joystick gp = new Joystick(1);  //GamePad
    CANJaguar leftA;
    CANJaguar leftB;
    CANJaguar rightA;
    CANJaguar rightB;
    public void robotInit() {
       try {
         leftA = new CANJaguar(2);
         leftB = new CANJaguar(3);
         rightA = new CANJaguar(4);
         rightB = new CANJaguar(5);
        } catch(Exception e) {
            e.printStackTrace();
        }

    }
    /**
     * This function is called periodically during operator control
     */
    public void teleopPeriodic() {
        try {
         //Tank Drive, Gamepad
         try {
            leftA.setX(gp.getRawAxis(2));
            leftB.setX(gp.getRawAxis(2));
            rightA.setX(gp.getRawAxis(4));
            rightB.setX(gp.getRawAxis(4));
         } catch(Exception e) {
             e.printStackTrace();
         }
        } catch (edu.wpi.first.wpilibj.can.CANNotInitializedException cnie) {
            cnie.printStackTrace();
        }
    }
    
}

Any help appreciated!

2

Is that the entire log?

I dont see where the can plugin is being loaded . . .

did you re-image the crio to v25 with the can plugin selected?

3

That is an excerpt. I cut some out for space.
The plugin loads fine. I have reimaged it with the 2011 Serial to CAN driver, V25.

I am sure the cables are fine, as I have salvaged them from our Breakaway bot.

Everything is fine, up until the point where I enable the robot.

If you need any more info, I can try to do it again tomorrow.

Thanks In Advance!

4

If you look carefully one of the jags doesn’t initialize properly which is called BEFORE you enable it. Are you sure your jags are numbered 2 3 4 5 instead of 1 2 3 4?

5

I am 90% sure that I have them numbered 2-5. I will check when I am in our shop in a few hours. Thanks!

6

The CANNotInitializedException means only one thing. The driver plugin is not registered with the system. Double check that you are actually loading the driver plugin.

-Joe

7

Thanks you two. I’ve reimaged it and it works now!:slight_smile: