leJOS and Lego Mindstorms EV3

This is where you talk about the EV3 software itself, installation issues, and programming talk.

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Re: leJOS and Lego Mindstorms EV3

Postby jerryP » Mon Aug 19, 2013 2:22 am

I see a folder ejre1.70.21 that has the bin/java in my lejosimage folder but I don't see how it is used to build the sd card.
The update_sdcard_sh script has only one reference to it:
jvm=${2:-`echo ejre*`}

Is that all that is required?
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Re: leJOS and Lego Mindstorms EV3

Postby skoehler » Mon Aug 19, 2013 2:30 am

According to Andy's guide, you must supply two arguments to update_sdcard.sh. The second argument is the folder of the ejre. The line you found just determines a default of the second parameter in case you didn't specify it. But you did specify it, didn't you?
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Re: leJOS and Lego Mindstorms EV3

Postby jerryP » Mon Aug 19, 2013 2:41 am

I supplied the ejre-7u21-fcs-b11-linux-arm-sflt-headless-04_apr_2013.tar.gz as the second argument as he showed in his example.
Is that correct?
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Re: leJOS and Lego Mindstorms EV3

Postby skoehler » Mon Aug 19, 2013 2:54 am

It seems to be correct. Also I was wrong. It's not a folder, it the path to the tgz. Let me take a look at the update script again.
You're sure, there are no error messages? Please post the output. If the script unpacks the ejre, you should see " .... Java" on the screen.
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Re: leJOS and Lego Mindstorms EV3

Postby jerryP » Mon Aug 19, 2013 3:10 am

I tried the process again and this time it did create the /lejos/ejre* directory but I got a ton of errors first and the card still did not work. I will try the whole process again - I think I am almost there.
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Re: leJOS and Lego Mindstorms EV3

Postby skoehler » Mon Aug 19, 2013 3:10 am

Which errors?
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Re: leJOS and Lego Mindstorms EV3

Postby jerryP » Mon Aug 19, 2013 3:56 am

During the update_sdcard, I first get hundreds of errors like
tar: ./var Cannot mkdir: Input/Output error
and then a bunch of cp: cannot create directory ....... Read-only file system
and some others
when it is all finished, the LMS2012_EXT directory looks like it was created OK but sometimes the lejos directory is there and sometimes it is not but either way it never works.

Do I need sudo in front of the update_sdcard script command - I have tried it both ways and they both result in a lot of these error messages.
The very first time I did this, everything when fine without errors but the lejos directory was missing. Now I get all these errors.
Also do I need to remove the ejre1.7.0_21 directory and copy the ejre-7u21-fcs-b11-linux-arm-sflt-headless-04_apr_2013.tar file back into the lejosimage directory each time before I retry creating the card?
I seem to be getting more messed up. I will probably stop for the night and try again tomorrow.
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Re: leJOS and Lego Mindstorms EV3

Postby skoehler » Mon Aug 19, 2013 4:05 am

jerryP wrote:During the update_sdcard, I first get hundreds of errors like
tar: ./var Cannot mkdir: Input/Output error


I cannot tell what is happening, but this seems serious. Either, the sd card is too small, the partitions are not created properly, or the the sd card is defect. Does the dmesg command show any suspicious errors in the kernel log?
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Re: leJOS and Lego Mindstorms EV3

Postby jerryP » Mon Aug 19, 2013 4:13 am

dmesg shows a lot of sdb2 I/O errors and
journel commit I/O errors

I am using a new 16 GB SD card but I am beginning to think it is bad myself. I will try another one tomorrow.
Thanks for all your help. I did get the lejos directory created once so if I start completely fresh with a new card maybe things will
work tomorrow.
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Re: leJOS and Lego Mindstorms EV3

Postby gloomyandy » Mon Aug 19, 2013 3:36 pm

Make sure that after you format the card you remove an re-insert it. If you are using Ubuntu you should see the two file systems being automatically mounted.
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Re: leJOS and Lego Mindstorms EV3

Postby jerryP » Mon Aug 19, 2013 5:23 pm

Thanks Andy,

I got it working today! I used a different computer and a new SD card and everything worked fine.
I really appreciate all the hard work you put into this. It is very nice. Now I just have to get down to work with it and see what I can do.
I am happy to see some serious language support coming for the EV3. I had been using GNAT Ada on the NXT and am hoping to get it on the
EV3 eventually. I know RobotC 4.0 is coming soon for the EV3 so we will have some choices.

Thanks again for everything! I'll let you know how things are going and look forward to your future efforts. It has been hard to get much real technical
data on the EV3. I hope Lego eventually produces the same type of documentation for the EV3 as they did for the NXT. It looks like a nice platform.

Jerry
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Re: leJOS and Lego Mindstorms EV3

Postby Snowy Owl » Tue Aug 20, 2013 3:28 am

Andy,
Great job on the install script. Worked on first try with a Sony 8GB micro SD card and Netgear WNA1100 WiFi.

}8-
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Re: leJOS and Lego Mindstorms EV3

Postby noki » Tue Aug 20, 2013 5:21 am

hi

When is leJOS for EV3 API published ?
is there completely backward compatibility with NXJ's?
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Re: leJOS and Lego Mindstorms EV3

Postby gloomyandy » Tue Aug 20, 2013 7:15 am

leJOS for the EV3 is currently under development. You can use a very early version of it today (but what we have is really only building blocks). Over time we will add to this. At some point we will make the first release for more general use, but we are a little way off of that. Many of the classes that are available on the NXT will also be available on the EV3, but it is unlikely that there will be complete compatibility between the two.

If you have an Eb3 or are thinking of getting one, you can help by contributing code, testing what we have, or by simply telling us how you plan to use the EV3...

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Re: leJOS and Lego Mindstorms EV3

Postby rubberduck » Wed Aug 21, 2013 1:26 pm

what do you think, when the first version will come out,

is it about some month or do you need a year or more for this?
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