The leJOS NXJ plugin on a 64bit Windows 7 PC

[JanOPedersen]

I am working on a very interesting project including robot vision, where I decided on the LEGO Mindstorms NXT platform for the hardware part. I used this for cost and ease of use considerations, but the later assumption may be wrong. When I ever get to have things working I will be more than happy to share my findings on this forum.

My PC is a 64 bit Windows 7 machine, a configuration that is quite common those days, so I guess other have seen the same problem.

It has been suggested in the book "Intelligence Unleashed -- Creating LEGO NXT Robots with Java" to only use the 32 bit version of eclipse. So this was what I installed after succesfully installing leJOS NXT (only comes in a 32 bit version). I also installed the 32 bit JDK 7. I can succesfully flash the NXT brick with leJOS firmware from the command prompt. I can also compile Java programs and flash them from the command prompt. But I need Eclipse as an IDE.

Now for the problem: when using the 32 bit version of eclipse it is not possible to install the leJOS NXJ plugin. I get the error:

Unable to read repository at http://lejos.sourceforge.net/tools/ecli ... ontent.xml.

The strange things is that with the 64 bit version of eclipse the install of leJOS NXJ plugin works as does building programs. But here the flashing of java programs to the NXT brick does not work and you get the following:

Linking ...
Program has been linked successfully
Uploading ...
leJOS NXJ> Failed to load USB comms driver: library jfantom.dll (windows/x86_64) was not found in C:\java\lejos_nxj\lib\pc\native
leJOS NXJ> Failed to find any NXTs
leJOS NXJ> Failed to connect to any NXT
No NXT found - is it switched on and plugged in (for USB)?
uploading the program failed with exit status 1

Of course the similar thing can not be tested on the 32 bit version of eclipse because it will need the plugin.

All in all this makes it impossible to use the eclipse IDE on modern PC's.

Any one got a clue ?

I think LEGO should be more into this stuff, it not just kids who still play with LEGO

[skoehler]

Unable to read repository at http://lejos.sourceforge.net/tools/ecli ... ontent.xml.

I have never heard about that error, and many people have been installing the eclipse plug-in just fine. Also, when building the update site, eclipse doesn't even create a content.xml. For us, it creates a content.jar, which contains a context.xml. So please give me some information:

Which eclipse version exactly did you use?
Which update site URL did you use?

Try http://lejos.sourceforge.net/tools/eclipse/plugin/nxj/ again.

[kaczor]

As far as I remember I had similar problems with 64bit Java and 64bit eclipse. I've also read in leJOS docs it will not work with 64 bit java at all. I've also tried and in fact it didn't. When I've installed 32bit JDK and 32bit eclipse - everything works like a charm. Maybe try one more time?

[WayneB]

Definitely make sure you're using 32bit Java.

You could be having trouble due to using JDK version 7. Trying using Java Version 6 Update 30 instead.

[skoehler]

Java 7 is fine.

[icemadsen]

I had the same experience a couple of days ago, when I reinstalled Windows 7. It turned out it was Java 7 that caused the problem with the update site, as there is something wrong with implementation of SOCKS, as far as I understood. It was not only the leJOS update site that was giving me problems, but it was every single update site. It just got timeout and could not install anything.

The solution for me was to uninstall Java 7 and install Java 6 and Eclipse worked fine again - it installs plugins just fine now.

- Kenneth

[NateR124]

I've got this same problem, where I can recognize the device via the regular leJOS set up, but not via the Eclipse plug-in. I have both Java 7 and a 64-bit version of Eclipse, has anyone been able to isolate which one is in fact the issue and which one of these is ok to have? Thanks!

EDIT: I tried myself, switching to 32 bit Eclipse fixed it for me. Keeping Java 7 was fine, still works!