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android_tutorial_teleop crashes

asked 2012-10-09 23:08:56 -0600

steven7 gravatar image

Hi guys, I am trying to run this example after successfully installing and building both rosjava_core and android_core. Then I am able to "import" the project to Eclipse and install it on my emulator with no error. However, whenever I touches the area around the joystick, the app crashes. This happens on my actual Android device as well (ASUS Eee Pad Transformers, with Android 4.0.6).

Does anyone how to solve the problem?

P/S: I do some diggings and one guy have the same problem but he solve it by adding the line currentVelocityCommand =publisher.newMessage();. I did try this method but the app crashes as well, maybe I added the line at the wrong place in VirtualJoystickView?

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Can you please provide an exact error message or even better a backtrace? (see

Lorenz gravatar image Lorenz  ( 2012-10-09 23:20:06 -0600 )edit

I received the NullPointerException like the other guy here encountered. Anyway I tried adding the line in different location by trial and error and it seems like the joystick can now move but another issue arises. T

steven7 gravatar image steven7  ( 2012-10-11 20:35:19 -0600 )edit

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answered 2013-02-13 16:11:11 -0600

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You should check 2 things:

1:The position you added the following line in "":

currentVelocityCommand = publisher.newMessage();

I think you should add the next of this line: publisher = connectedNode.newPublisher("~cmd_vel", geometry_msgs.Twist._TYPE);

2:Whether you can rebuild "android_honeycomb_mr2" and add the jar file in your teleop package successfully.

in the root of "android_honeycomb_mr2" directory, type the following command again, ../gradlew debug and the same command in "android_teleop" directory.

If this doesn't work, I'll see the error messages in logcat.

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Asked: 2012-10-09 23:08:56 -0600

Seen: 909 times

Last updated: Feb 13 '13