FLL-leJOS

Master/menu infrastructure for running FIRST LEGO League mission programs written in leJOS on the EV3

Version 2.1.1

Author: John Meshulam

FLL-leJOS was created with FLL teamns in mind and aims to provide an intuitive and simple way to program FLL robots using Java.

This is the stup guide! For examples and documentation, visit the Repository's Wiki!

Should I use this?

Positives

• Simple to use and teach while installed
• Intuitive and accessible even for teams with little/no coding experience
• Provides a menu for selecting runs, similar to Mindstorms
• Provides support for interrupting robot actions and restarting failed runs instantly

Negatives

• Complicated setup that requires moderate experience with Java and file handling
• Menu is still extremely basic and some tools are still missing (This will be fixed at a later date)
• Although FLL-leJOS is significantly simpler to use than vanilla leJOS, basic (and some intermediate) Java is still required for teams to use properly. This takes time and effort to teach, and may not fit all audiences.

Prequisites

• EV3 Brick
• Micro SD or Micro SDHC card (NOT SDXC!) with at least 4-32GB. (Cards with over 32GB will not work!)
• A Computer running windows 7 or later, with an SD card reader
  • OPTIONAL: Bluetooth or wifi capability
• Patience. The setup and install process is long and complicated. Don't be afraid if it fails the first time.

Setup

leJOS on the EV3

1. Download JDK-8 (latest update, windows x64) from the official Oracle website
2. Download the latest leJOS EV3 from the lejos sourceforge page. When the installer completes, do not run the EV3SD utility.
3. Format the SD card (You can use the official SD association software available on their website)
4. After you have finished formatting, it's time to create the embedded JRE. These instructions are adapted from this lejos forum post
   • Step 1: Download and install 7-Zip (win64) from the official website
   • Step 2: Go to this ejdk download page and download Java SE embedded version 8 - (This will download ejdk-8-fcs-b132-linux-arm-sflt-03_mar_2014.tar.gz, which I will refer to as the embedded JDK file)
   • Step 3: Create a directory somewhere on your disk. For the rest of this tutorial I will be using C:\myLejosInstall
   • Step 4: Unzip the embedded JDK file in C:\myLejosInstall. For simplicity purposes, rename the extracted directory to ejdk8
   • Step 5: Start a new CMD window inside C:\myLejosInstall. This can be done by pressing SHIFT + Right Click and selecting new command prompt window here. If you are using windows 10, open a powershell window instead and type cmd to switch to command prompt.
   • Step 6: Enter the following commands:

     $ cd ejdk8\ejdk1.8.0\bin
     $ jrecreate.bat --dest newjre --profile compact2 --vm client

     This will create the new EJRE files in a directory named newjre located under ejdk8\ejdk1.8.0\bin. Wait for the process to complete, and then close the cmd window.
   • Step 7: Open C:\myLejosInstall\ejdk8\ejdk1.8.0\bin, and move the newjre directory to C:\myLejosInstall
   • Step 8: Rename the newjre directory to ejre-8-b132-linux-arm-sflt (IMPORTANT!)
   • Step 9: Right click on the directory, select 7Zip -> Add to archive. Select the tar format and accept. This should create ejre-8-b132-linux-arm-sflt.tar
   • Step 10: Right click on the directory again, select 7Zip -> Add to archive. Select the gzip format and accept. This should create ejre-8-b132-linux-arm-sflt.tar.gz
5. Open your newly formatted SD card with file explorer, and copy the ejre-8-b132-linux-arm-sflt.tar.gz from the previous step to it.
6. Go to your leJOS install location (default: C:\Program Files\leJOS EV3)
7. Extract the lejosimage.zip file using 7Zip to your SD card.
8. Remove the SD card from your computer, insert it into your EV3 brick, and power on. If you have completed all the steps properly, it will start install leJOS, which takes around 10 minutes. If it doesnt work, go ahead and redo step 4, which is where most problems occur.

leJOS on your PC

(If you did not install leJOS for the EV3 brick first, complete steps 1 and 2 from the EV3 setup before starting)

1. Download eclipse from the official website. Run the installer and select Eclipse IDE for JAva Developers
2. Open eclipse, select Help -> Install new software
3. Follow the instructions on the leJOS wiki to install the leJOS eclipse plugin

Connecting the EV3 to you PC

Via Bluetooth

1. Setup your brick name and IP to something unique instead of the default EV3 and 10.0.1.1. This is done via the brick's on-screen menu:
   • Select system and Change name to set the brick name
   • Select PAN, Access pt, Address, Advanced, set your desired IP, and press the back button until you return to the main menu. The brick will take a few seconds to set your IP after you exit!
2. On the PC, open Control Panel, and select Network and Sharing Center. There should be a Change adapter settings option on the top left corner. Click it, and a new window should open.
3. Inside the new vindow, click on the Bluetooth network connection adapter, and select View bluetooth network devices from the top bar.
   • a. If this is the FIRST TIME you are connecting this brick to the PC, select Add a device, wait for the PC to recognize it (this may take 2-3 minutes!), and complete the setup process. You will be prompted for a password which will be 1234 unless it has been changed by the user.
4. Select your device from the menu, and click Connect using Access point from the top bar. If you completed this process corretly, a propt will show up with the Bluetooth icon and the words connection succcessful
5. Open Eclipse, select Window, Preferences, and enter the EV3 tab. Check Connect to named brick and input your brick's IP.

Via USB

1. Stick one end of the USB cable into the PC
2. Stick the other end of the USB cable into the EV3
3. Profit.
4. Open Eclipse, select Window, Preferences, and enter the EV3 tab. Check Connect to named brick and input your brick's IP

Setting up FLL-leJOS inside Eclipse

Stable Releases

1. Go to the releases tab of this project
2. Download the source code
3. Inside Eclipse, right click inside the package manager and select import. Under the General folder, select the Archive File option, and complete the import process.
4. Right click the project. Select leJOS -> convert to leJOS EV3 project

For information about pushing your robot code and using Git from Eclipse in general, check out this guide.

Clone the Repository (Not recommended!)

1. Inside Eclipse, right click inside the package manager and select import. Under the Git folder, use the Projects from git (with smart import) option (If your eclipse is older, you will not have this option. In that case, download git for windows and use git bash, or update your Eclipse)
2. Paste the repository URL inside the first field, and finish the import. Everything will updaate automatically.
3. Right click the repository. Select leJOS -> convert to leJOS EV3 project

For information about pushing your robot code to another repository, and using Git from Eclipse in general, check out this guide.