Creating and Using ROS Nodes in the NengoROS System

Author Jaroslav Vitku [vitkujar@fel.cvut.cz]

About

This repository contains set of nodes for purposes of demonstration of NengoROS integration. It also contains projectTemplate which can serve as a starting point for creating new (Nengo)ROS nodes in Java.

This is a part of NengoRos multi-project build, so there is no need to install any of the demo nodes.

Running the NengoROS Demos

In the complete installation of Nengoros, all demo scripts from this repository are symlinked into the folder nengo/simulator-ui/nr-demo. To run these nodes, run Nengo (or nengo-cl):

cd nengo/simulator-ui/
./nengo

and open the demo script by writing the command into the Nengo console:

run nr-demo/minmaxint.py

Template for Creating New Project with ROS Nodes

The script helper is able to initialize new Nengoros project for you. Running the script:

./demonodes/helper -i

will copy the proejctTemplate into the nengo/ workspace. Feel free to rename it. You can now edit the example ROS nodes under src/main/java.

Building the Project

In order to build your project run from the root of your project:

./gradlew build

To refresh (e.g. after renaming the folder) the eclipse project:

./gradlew eclipse

To install the project into the local maven repository:

./gradlew install

Usage of Newly Created ROS Nodes

There are several possibilities how to run your newly created nodes:

Running the nodes independently

Each ROSjava node produced in this way is 100% compatible with ROS infrastructure and can be launched either under roscore from ROS installation or jroscore from the nengoros project. To launch the node it is necessary to:

Create the runnable application by launching from the project root:

./gradlew installApp

Run the core, e.g. for jroscore:

cd nengoros/jroscore && ./jroscore

Launch the generated script with the full node name in a new terminal:

cd nengoros/projectTemplate
./build/install/projectTemplate/bin/projectTemplate org.hanns.myPackage.DemoPublisher

Launch subscriber to receive messages in a new terminal:

cd nengoros/projectTemplate
./build/install/projectTemplate/bin/projectTemplate org.hanns.myPackage.DemoSubscriber

Now, there should be two independently running ROSjava nodes which communicate over the TCP/IP via the ROS network. Note that you can change some properties of nodes by adding optional command line arguments, for more information, see remapping arguments.

Integration with NengoROS

In order to use this collection of nodes in Nengoros, you have to add a dependency of nengo/simulator-ui sub-project on your project. To do this, you have to:

Add your project to the multi-project Nenoros build

Edit the settings.gradle file and add the name of your new project there. So the result could be:

 // howto: '[folderName]:[subFolderName]:[projectName==folderName]'  (no package names here)
 include 'logic:gates', 'projectTemplate'

add the dependency to the nengo/simulator-ui project by editing the nengo/simulator-ui/rosjava.build.gradle, so the result could be:

 dependencies {
     	compile project(':nengo:simulator')
     	compile fileTree(dir: 'lib', include: '**/*.jar')
     	compile 'ros.rosjava_core:rosjava:0.0.0-SNAPSHOT'
     	compile 'org.hanns.logic:gates:0.0.1-SNAPSHOT'
 		//
 		// howto: '[projectFolder]:[projectName]' 
 		compile project('projectTemplate')
 }

Recompile and reinstall the Nengoros project by running:
```
 ./tool -nf
```
If you want to launch Nengo from class files, add new dependency to the simulator-ui/nengo (and nengo-cl) scripts. That is e.g. to the local folder which is auto-generated by the command ./gradlew install:
```
 NODES=$NODES:$N_HOME/../../projectTemplate/build/libs/projectTemplate-0.0.1-SNAPSHOT.jar
```

Link, or copy project scripts to the Nengo Simulator

In order to copy (or symlink) additional scripts and GUI data (described below) the script called demonodes/linkdata can be used. This script deploys/links the following files into the Nengo simulator:

RosNode helper scripts from: [YourProjectFolder]/python/rosnodes/*
Drag&Drop GUI images from: [YourProjectFolder]/images/nengoIcons/*
Drag&drop scripts from: [YourProjectFolder]/python/nef/templates/*
Other scripts from: [YourProjectFolder]/python/scripts/*
Nengoros demo scripts from: [YourProjectFolder]/python/nr-demo/*

For more information about script usage, run:

./linkdata -h

Launch your Nodes from the Nengo Simulator

From now, you can create simple python script which creates representation of your ROS nodes in the Nengo. Example of simple script, which:

creates network
for each ROS node creates NeuralModule
places these new neural modules into the network
connect them with other components

is contained under projectTemplate/python/myNetwork.py, and after use of linkdata script, this file should be linked under nengoros/nengo/simulator-ui/nr-demo/projectTemplate.

Then, the script can be launched, simply run the ./nengo and then write into the command-line interface: run with relative path to your script, so e.g.:

run nr-demo/projectTemplate/myNetwork.py

Adding Drag and Drop Icon into the Nengo GUI

This is not mandatory, but allows user to easily add nodes into the simulation in the GUI and to simplify use of new components in jython scripts. For more information about how to add a GUI template into the Nengo simulator, see the tutorial from the authors of Nengo on: http://nengo.ca/docs/html/advanced/dragndrop.html .

Basically, you have to:

Add image of each node (group of nodes)under: projectTemplate/images/nengoIcons
For each new node (group of nodes), add an initialization script under: projectTemplate/python/nef/templates.
Link these files into the Nengo simulator (./linkdata -h)
Add these new templates into the nengo/simulator-ui/python/nef/templates/__init__.py file
Restart Nengo, you should see your nodes in the left panel

TODO

Update scirpts under projectTemplate/python to match information in this README.md
The tool should generate also files for ROS meta-package (for catkin support (package.xml et al)).

jvitku/demonodes