Beginners help

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Beginners help

Postby nick22 » Sun Jul 27, 2014 10:26 pm

Hi

I'm pretty new to Java but have some programming experience.

I've followed the wiki guide to download Java and leJOS but I must have done something wrong as I'm getting errors.

I'm running the latest Mac OS, have downloaded Java EE IDE for Web developers Luna v 4.4.0

I've installed the leJOS plugin and I can see many leJOS menu items, so it appears to have worked.

When I try to run the sample program on the wiki I get an 'unbound classpath container' error on the org.lejos.ev3.ldt.LEJOS_EV3_LIBRARY_CONTAINER.

When I check the libraries in the build path preferences the leJOS is present but has (unbounded) appended to the end. I've tried to remove and reinstall but it remains the same.

I can't find where in finder the leJOS has installed, where the libraries are or where it links to - in fact I can't find any reference to any leJOS files in finder!

Also when I first installed leJOS and tried to set the EV3_home location I wasn't able to find a suitable path....

Many thanks for any help
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Re: Beginners help

Postby gloomyandy » Sun Jul 27, 2014 10:45 pm

For leJOS please tell us what exactly it was that you downloaded and how you installed it? Have you created your SD card yet?

I think you would have been better off installing the standard "Eclipse IDE for Java Developers" rather then the version aimed at EE developers.

Note that the environment variable is EV3_HOME not EV3_home.
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Re: Beginners help

Postby nick22 » Mon Jul 28, 2014 3:05 am

thanks.

I've reinstalled the non EE version and it seems to work now - yay

now I have added the sample code..

LCD.drawString("Plugin Test", 0, 4);
Delay.msDelay(5000);

and have error messages of 'Delay cannot be resolved"??? not sure what this means

Thanks again!
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Re: Beginners help

Postby gloomyandy » Mon Jul 28, 2014 9:06 am

Nick, you need to be as specific as you can when asking for help. When do you get that message? Is it from eclipse? Is it when you try and run your code? Also it really helps if you post the code that is causing the problem. Have you imported the Delay class for use by your program?
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Re: Beginners help

Postby nick22 » Mon Jul 28, 2014 3:03 pm

Sorry, thanks for your help

The error is from running eclipse - the code editor in eclipse also underlines the delay class in red.

I haven't imported the delay class as I thought it was auto loaded as part of the leJOS library.

The code is copied and pasted from the leJOS wiki site

Thanks again

Nick
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Re: Beginners help

Postby gloomyandy » Mon Jul 28, 2014 3:18 pm

So? Did you import the class? Did the error go away?

Please don't say things like "the code was copy and pasted from the leJOS wiki site", please provide either the code or an actual link. If you don't this means that anyone trying to help you will have to go hunting for the code. There is a good chance that they will not bother, if you want help make it easy for people to help you...
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Re: Beginners help

Postby nick22 » Tue Jul 29, 2014 2:34 am

yes the program works now. Now I need to look into creating an SD card etc.

But thanks for your help, and I promise to be more specific in the future.

Thanks again
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Re: Beginners help

Postby nick22 » Thu Jul 31, 2014 10:06 pm

Hi again

Im trying to build the SD card for my EV3 brick.

Following the steps on the wiki... it says "You should then unzip the lejosimage.zip file from the leJOS home directory to the root directory of the card"

I can't find anything on the leJOS website with such a named file. I can find a download for a file called " leJOS_NXJ_0.9.1beta-3.tar.gz (13.7 MB)", but I thought that this is the file you need to install on the Mac?

Do I need to install this file on the SD card as well?

Many thanks

Nick
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Re: Beginners help

Postby gloomyandy » Fri Aug 01, 2014 12:17 am

You should have used this file:
http://sourceforge.net/projects/lejos/f ... z/download

When you expanded it (which I think you must have done already), then one of the files inside should have been the sdcard card image file lejosimage.zip file, so you should have this file already on your system. It is not a file that you download separately from the web.
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Re: Beginners help

Postby nick22 » Fri Aug 01, 2014 2:34 am

Many thanks - found the file, as you say, already downloaded.

Now choosing the JRE file and there is a large selection of v7 (or v6/7) files as below,

ARMv6/7 Linux - Headless - Client Compiler EABI, VFP, HardFP ABI, Little Endian1 31 MB Downloadejre-7u60-fcs-b19-linux-arm-vfp-hflt-client_headless-07_may_2014.tar.gz
ARMv6/7 Linux - Headful EABI, VFP, HardFP ABI, Little Endian1 35 MB Downloadejre-7u60-fcs-b19-linux-arm-vfp-hflt-client_headful-07_may_2014.tar.gz
ARMv7 Linux - Headless - Server Compiler EABI, VFP, HardFP ABI, Little Endian1 32 MB Downloadejre-7u60-fcs-b19-linux-arm-vfp-hflt-server_headless-07_may_2014.tar.gz
ARMv6/7 Linux - Headless - Client Compiler EABI, VFP, SoftFP ABI, Little Endian2 31 MB Downloadejre-7u60-fcs-b19-linux-arm-vfp-sflt-client_headless-07_may_2014.tar.gz
ARMv6/7 Linux - Headful EABI, VFP, SoftFP ABI, Little Endian2 35 MB Downloadejre-7u60-fcs-b19-linux-arm-vfp-sflt-client_headful-07_may_2014.tar.gz
ARMv7 Linux - Headless - Server Compiler EABI, VFP, SoftFP ABI, Little Endian2 32 MB Downloadejre-7u60-fcs-b19-linux-arm-vfp-sflt-server_headless-07_may_2014.tar.gz

No sure which one..?

Thanks again - I really appreciate this help.
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Re: Beginners help

Postby nick22 » Fri Aug 01, 2014 2:48 am

Am I right in thinking that once I've got leJOS working on the SD card, I can, at any time, remove the SD card and the EV3 will automatically boot up using the OEM OS?

Thanks
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Re: Beginners help

Postby gloomyandy » Fri Aug 01, 2014 6:53 am

Yes if you remove the sdcard you go back to whatever you installed on your EV3. The following page has the correct download:
http://java.com/legomindstorms
Do not use the Java 8 download.
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