### Start Android Emulator Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Command to launch a specific Android Virtual Device. ```bash emulator -avd vm-android-14 ``` -------------------------------- ### Install Android APK Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Use ADB to install the jros1droid application package onto the emulator. ```bash adb install id.jros1droid-v-debug.apk ``` -------------------------------- ### Running the Publisher Application Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Commands to execute the PublisherApp depending on the dependency management setup. ```bash java -cp "/libs/*" PublisherApp.java ``` ```bash depresolve io.github.lambdaprime:jros1client:8.0 --exec "java PublisherApp.java" ``` -------------------------------- ### Subscribe to ROS Topics Source: http://portal2.atwebpages.com/jrosclient/jrosclient-command.html Example of publishing to a topic and subscribing to it using the jrosclient command. ```bash rostopic pub -r 10 helloRos std_msgs/String "hello there" ``` ```bash jrosclient rostopic echo /helloRos id.jrosmessages.std_msgs.StringMessage ``` -------------------------------- ### Execute SubscriberApp Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Commands to run the subscriber application depending on the installation method. ```bash java -cp "/libs/*" SubscriberApp.java ``` ```bash depresolve io.github.lambdaprime:jros2client:9.0 --exec "java SubscriberApp.java" ``` -------------------------------- ### Subscriber Output Examples Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Expected console output when receiving messages from the ROS topic. ```text { "data": "Hello ROS" } { "data": "Hello ROS" } { "data": "Hello ROS" } ``` ```text { "data": "Hello ROS" } { "data": "hello there" } ``` -------------------------------- ### Android Virtual Device Configuration Output Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Example output showing the configuration details of an Android Virtual Device. ```text Available Android Virtual Devices: Name: vm-android-14 Target: Default Android System Image Based on: Android API 34 Tag/ABI: default/x86_64 Sdcard: 512 MB ``` -------------------------------- ### Launch isaac_ros_jetson_stats Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Command to start the ROS 2 launch file for monitoring Jetson statistics. ```bash ros2 launch isaac_ros_jetson_stats jtop.launch.py ``` -------------------------------- ### Subscriber Execution Commands Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Commands to run the subscriber application depending on the installation method. ```bash java -cp "/libs/*" SubscriberApp.java ``` ```bash depresolve io.github.lambdaprime:jros1client:8.0 --exec "java SubscriberApp.java" ``` -------------------------------- ### Correct Field Initialization Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Example of a properly initialized field ensuring the object is serialized correctly. ```java public Time stamp = new Time(); ``` -------------------------------- ### List Android Virtual Devices Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Use this command to verify available Android Virtual Devices before starting the emulator. ```bash avdmanager list avd ``` -------------------------------- ### Subscriber Output with Multiple Publishers Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Example output showing messages received from multiple publishers. ```text { "data": "Hello ROS" } { "data": "hello there" } ``` -------------------------------- ### Manually install jros2client Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Extract the jros2client package to a local directory for use in Java scripts or jshell. ```bash unzip -d jros2client.zip ``` -------------------------------- ### Array Field Initialization Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Example of initializing an array field with an empty array to prevent serialization errors. ```java public Point32Message[] points = new Point32Message[0]; ``` -------------------------------- ### Add jrosclient to PATH Source: http://portal2.atwebpages.com/jrosclient/jrosclient-command.html Commands to add the jrosclient installation directory to the system PATH for bash and zsh shells. ```bash echo "export PATH=$PATH:" >> ~/.bashrc ``` ```zsh echo "export PATH=$PATH:" >> ~/.zshrc ``` -------------------------------- ### Fixed Size Array Definition Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Example of defining a fixed-size array using the @Array annotation. ```java @Array(size = 4) public double[] coef = new double[0]; ``` -------------------------------- ### Incorrect Null Field Initialization Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Example of an incorrectly initialized field that will cause serialization issues due to null values. ```java public Time stamp; ``` -------------------------------- ### Build and Run diagnostics_otel Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Commands to clone the repository, build the project with Gradle, and execute the resulting JAR file. ```bash git clone https://github.com/lambdaprime/jros2client cd jros2client/jros2client.examples/diagnostics_otel gradle clean build ``` ```bash java -jar build/libs/diagnostics_otel.jar ``` -------------------------------- ### Publishing to a ROS 2 topic in Java Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Demonstrates creating a JRos2Client, registering a publisher for a topic, and sending StringMessage objects periodically. ```java import id.jros2client.JRos2ClientConfiguration; import id.jros2client.JRos2ClientFactory; import id.jrosclient.TopicSubmissionPublisher; import id.jrosmessages.std_msgs.StringMessage; /** * Creates a new topic and publishes messages to it. */ public class PublisherApp { public static void main(String[] args) throws Exception { var configBuilder = new JRos2ClientConfiguration.Builder(); // use configBuilder to override default parameters (network interface, RTPS settings etc) var client = new JRos2ClientFactory().createClient(configBuilder.build()); String topicName = "/helloRos"; var publisher = new TopicSubmissionPublisher<>(StringMessage.class, topicName); // register a new publisher for a new topic with ROS client.publish(publisher); while (true) { publisher.submit(new StringMessage().withData("Hello ROS")); System.out.println("Published"); Thread.sleep(1000); } // usually we need to close client once we are done // but here we keep it open so that subscriber will keep // printing messages indefinitely } } ``` -------------------------------- ### Run ROS1 publisher Source: http://portal2.atwebpages.com/jrosclient/ros_bridge.html Command to publish string messages to the helloRos topic in a ROS1 environment. ```bash rostopic pub -r 10 helloRos std_msgs/String "hello there" ``` -------------------------------- ### Enable Debug Logging for ROS Clients Source: http://portal2.atwebpages.com/jrosclient Use these commands to run publisher applications with debug logging enabled for ROS2 and ROS1 respectively. ```bash java -Djava.util.logging.config.file=jros2client-debug.properties -cp "libs/*" examples/PublisherApp.java ``` ```bash java -Djava.util.logging.config.file=jros1client-debug.properties -cp "libs/*" examples/PublisherApp.java ``` -------------------------------- ### jrosclient Usage Syntax Source: http://portal2.atwebpages.com/jrosclient/jrosclient-command.html General syntax for executing the jrosclient command with available options. ```bash jrosclient [--masterUrl MASTER_URL] [--nodePort NODE_PORT] [--truncate MAX_LENGTH] [--debug] [args ...] ``` -------------------------------- ### Initialize OpenTelemetry Meter Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Retrieves a global meter instance for the application. ```java meter = GlobalOpenTelemetry.getMeter(DiagnosticsOpenTelemetryApp.class.getSimpleName()); ``` -------------------------------- ### Publisher Application Output Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Expected console output when the publisher is running successfully. ```text Published Published Published Published ... ``` -------------------------------- ### Subscribe to ROS Diagnostics Topic Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Sets up a subscriber for the /diagnostics_agg topic to process incoming diagnostic messages. ```java var configBuilder = new JRos2ClientConfiguration.Builder(); // use configBuilder to override default parameters (network interface, RTPS settings etc) var client = new JRos2ClientFactory().createClient( configBuilder.build()); var topicName = "/diagnostics_agg"; // register a new subscriber with default QOS policies // users can redefine QOS policies using overloaded version of subscribe() method client.subscribe(new TopicSubscriber<>(DiagnosticArrayMessage.class, topicName) { @Override public void onNext(DiagnosticArrayMessage item) { System.out.println("New item received"); try { emitToOpenTelemetry(item); } finally { // request next message getSubscription().get().request(1); } } }); ``` -------------------------------- ### Subscribing to the Topic via rostopic Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Command and expected output to verify the published messages using the ROS CLI. ```bash rostopic echo helloRos ``` ```text data: "Hello ROS" --- data: "Hello ROS" --- data: "Hello ROS" --- data: "Hello ROS" --- data: "Hello ROS" ``` -------------------------------- ### Available rostopic Commands Source: http://portal2.atwebpages.com/jrosclient/jrosclient-command.html Commands for echoing topic messages and listing system information. ```bash rostopic echo [-n COUNT] ``` ```bash rostopic list ``` -------------------------------- ### Publishing to a ROS topic in Java Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Creates a ROS topic and publishes string messages every second. Requires jros1client dependencies on the classpath. ```java import id.jros1client.JRos1ClientConfiguration; import id.jros1client.JRos1ClientFactory; import id.jrosclient.TopicSubmissionPublisher; import id.jrosmessages.std_msgs.StringMessage; /** Creates a new topic and publishes messages to it. */ public class PublisherApp { public static void main(String[] args) throws Exception { var config = new JRos1ClientConfiguration(); // host address where jrosclient is running and to which other ROS nodes // will communicate config.setHostAddress("localhost"); // specify URL of the master node var client = new JRos1ClientFactory().createClient("http://localhost:11311/", config); String topicName = "helloRos"; var publisher = new TopicSubmissionPublisher<>(StringMessage.class, topicName); // register a new publisher for a new topic with ROS client.publish(publisher); while (true) { publisher.submit(new StringMessage().withData("Hello ROS")); System.out.println("Published"); Thread.sleep(1000); } // usually we need to close client once we are done // but here we keep it open so that subscriber will keep // printing messages indefinitely } } ``` -------------------------------- ### Subscribe to a ROS 2 topic in Java Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Implements a subscriber for the /helloRos topic using JRos2ClientFactory. Requires the jros2client library in the classpath. ```java import id.jros2client.JRos2ClientConfiguration; import id.jros2client.JRos2ClientFactory; import id.jrosclient.TopicSubscriber; import id.jrosmessages.std_msgs.StringMessage; /** * Subscribes to ROS topic */ public class SubscriberApp { public static void main(String[] args) throws Exception { var configBuilder = new JRos2ClientConfiguration.Builder(); // use configBuilder to override default parameters (network interface, RTPS settings etc) var client = new JRos2ClientFactory().createClient(configBuilder.build()); var topicName = "/helloRos"; // register a new subscriber with default QOS policies // users can redefine QOS policies using overloaded version of subscribe() method client.subscribe( new TopicSubscriber<>(StringMessage.class, topicName) { @Override public void onNext(StringMessage item) { System.out.println(item); // request next message getSubscription().get().request(1); } }); // usually we need to close client once we are done // but here we keep it open so that subscriber will keep // printing messages indefinitely } } ``` -------------------------------- ### Define Jetson Statistics Metrics Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Defines the list of Jetson hardware statistics to be tracked. ```java List isaac_ros_jetson_stats = List.of( "/jtop/CPU/jetson_stats/temp/cpu", "/jtop/Board/pwmfan/PWM 0", "/jtop/Board/pwmfan/RPM 0", "/jtop/GPU/jetson_stats/gpu/gpu", "/jtop/GPU/jetson_stats/temp/gpu", "/jtop/GPU/gpu/Used", "/jtop/Memory/ram/Use"); ``` -------------------------------- ### Subscribing to topic via ROS 2 CLI Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Command and expected output for verifying the published messages using the ros2 echo utility. ```bash ros2 topic echo helloRos std_msgs/String ``` ```text data: "Hello ROS" --- data: "Hello ROS" --- data: "Hello ROS" --- data: "Hello ROS" --- data: "Hello ROS" ``` -------------------------------- ### Run ROS2 subscriber Source: http://portal2.atwebpages.com/jrosclient/ros_bridge.html Command to listen for string messages on the helloRos topic in a ROS2 environment. ```bash ros2 topic echo helloRos std_msgs/String ``` -------------------------------- ### Configure OpenTelemetry Elasticsearch Exporter Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Initializes a PeriodicMetricReader to export metrics to Elasticsearch every 3 seconds. ```java /** Setup OpenTelemetry to send metrics to Elasticsearch */ private static void setupMetrics() { var metricReader = PeriodicMetricReader.builder( new ElasticsearchMetricExporter( URI.create("ELASTICSEARCH_URL/diagnostics_otel"), Optional.empty(), Duration.ofSeconds(5), true)) .setInterval(Duration.ofSeconds(3)) .build(); var sdkMeterProvider = SdkMeterProvider.builder().registerMetricReader(metricReader).build(); OpenTelemetrySdk.builder().setMeterProvider(sdkMeterProvider).buildAndRegisterGlobal(); } ``` -------------------------------- ### Unzip jros1client package Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html Command to extract the jros1client distribution package to a specified directory. ```bash unzip -d jros1client.zip ``` -------------------------------- ### Publish to ROS 2 topic via CLI Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Command to publish a message to the /helloRos topic using the ROS 2 CLI tool. ```bash ros2 topic pub -r 3 helloRos std_msgs/String 'data: "hello there"' ``` -------------------------------- ### List Network Interfaces with jshell Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Use this jshell command to identify the correct network interface name for your system. ```java jshell> NetworkInterface.networkInterfaces().forEach(System.out::println) ``` -------------------------------- ### Java Dependencies for jros2client and OpenTelemetry Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Required dependencies for the jros2client library and OpenTelemetry API. ```gradle implementation "io.github.lambdaprime:jros2client:10.0" implementation "io.opentelemetry:opentelemetry-api:1.43.0" ``` -------------------------------- ### Create Metric Gauges Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Registers a gauge for each defined Jetson statistic. ```java Map gauges = new HashMap<>(); isaac_ros_jetson_stats.stream() .forEach(stat -> gauges.put(stat, meter.gaugeBuilder(toMetricName(stat)).build())); ``` -------------------------------- ### Subscriber Application Implementation Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros1client.html A Java application that connects to a ROS master and subscribes to a specific topic to process incoming messages. ```java import id.jros1client.JRos1ClientConfiguration; import id.jros1client.JRos1ClientFactory; import id.jrosclient.TopicSubscriber; import id.jrosmessages.std_msgs.StringMessage; /** Subscribes to ROS topic */ public class SubscriberApp { public static void main(String[] args) throws Exception { var config = new JRos1ClientConfiguration(); // host address where jrosclient is running and to which other ROS nodes // will communicate config.setHostAddress("localhost"); // specify URL of the master node var client = new JRos1ClientFactory().createClient("http://localhost:11311/"); var topicName = "/helloRos"; // register a new subscriber client.subscribe( new TopicSubscriber<>(StringMessage.class, topicName) { @Override public void onNext(StringMessage item) { System.out.println(item); // request next message getSubscription().get().request(1); } }); // usually we need to close client once we are done // but here we keep it open so that subscriber will keep // printing messages indefinitely } } ``` -------------------------------- ### Verify message publication output Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Observe the console output to confirm that messages are being successfully published. ```text Published Published Published Published Published Published Published Published Published ... ``` -------------------------------- ### Configure Network Interface in jros2client Source: http://portal2.atwebpages.com/jrosclient/Quick_Start_jros2client.html Use JRos2ClientConfiguration to explicitly set the network interface when the default selection is incorrect. ```java var configBuilder = new JRos2ClientConfiguration.Builder(); // run on network interface with name "eth0" configBuilder.rtpsTalkConfiguration( new RtpsTalkConfiguration.Builder() .networkInterface("eth0") .build()); new JRos2ClientFactory().createClient(configBuilder.build()); ``` -------------------------------- ### Calculate ROS1 MD5 Sum Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Command to retrieve the MD5 sum required for ROS1 message definitions. ```bash rosmsg md5 geometry_msgs/PolygonStamped ``` ```text c6be8f7dc3bee7fe9e8d296070f53340 ``` -------------------------------- ### Emit Metrics to OpenTelemetry Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Parses ROS diagnostic messages and updates the corresponding OpenTelemetry gauges. ```java void emitToOpenTelemetry(DiagnosticArrayMessage item) { for (var s : item.status) { var name = s.name.data; for (var pair : s.values) { var keyName = pair.key.data; var fullName = name + "/" + keyName; var gauge = gauges.get(fullName); if (gauge == null) continue; try { var val = parseMeasurement(pair.value.data); gauge.set(val); System.out.println(fullName + "=" + val); } catch (Exception e) { System.err.format( "Could not parse double value from %s: %s", pair, e.getMessage()); } } } } ``` -------------------------------- ### Polygon ROS Definition Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html The ROS definition file content for geometry_msgs/Polygon. ```text #A specification of a polygon where the first and last points are assumed to be connected Point32[] points ``` -------------------------------- ### Calculate ROS1 MD5 Sum Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Command to retrieve the MD5 sum for a ROS message type. ```bash rosmsg md5 geometry_msgs/Polygon cd60a26494a087f577976f0329fa120e ``` -------------------------------- ### PolygonStamped ROS Definition Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html The ROS definition file content for geometry_msgs/PolygonStamped. ```text # This represents a Polygon with reference coordinate frame and timestamp Header header Polygon polygon ``` -------------------------------- ### Define ROS1 PolygonStampedMessage Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Java class definition for the ROS1 geometry_msgs/PolygonStamped message, including the required MD5 sum metadata. ```java import id.jros1messages.std_msgs.HeaderMessage; /** Example of custom message definition */ @MessageMetadata( name = PolygonStampedMessage.NAME, fields = {"header", "polygon"}, md5sum = "c6be8f7dc3bee7fe9e8d296070f53340") public static class PolygonStampedMessage implements Message { static final String NAME = "geometry_msgs/PolygonStamped"; public HeaderMessage header = new HeaderMessage(); public PolygonMessage polygon = new PolygonMessage(); public PolygonStampedMessage withPolygon(PolygonMessage polygon) { this.polygon = polygon; return this; } public PolygonStampedMessage withHeader(HeaderMessage header) { this.header = header; return this; } } ``` -------------------------------- ### ROS2 topic output Source: http://portal2.atwebpages.com/jrosclient/ros_bridge.html Expected output format when receiving forwarded messages in the ROS2 terminal. ```text data: Hello ROS --- data: Hello ROS --- data: Hello ROS --- data: Hello ROS ``` -------------------------------- ### Elasticsearch Exporter Dependency Source: http://portal2.atwebpages.com/jrosclient/diagnostics_otel Optional dependency required to export OpenTelemetry metrics to an Elasticsearch backend. ```gradle implementation "io.github.lambdaprime:id.opentelemetry-exporters-pack:4.0" ``` -------------------------------- ### Define ROS2 PolygonStampedMessage Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Java class definition for the ROS2 geometry_msgs/PolygonStamped message using the jros2messages Header. ```java import id.jros2messages.std_msgs.HeaderMessage; /** Example of custom message definition */ @MessageMetadata( name = PolygonStampedMessage.NAME, fields = {"header", "polygon"}) public static class PolygonStampedMessage implements Message { static final String NAME = "geometry_msgs/PolygonStamped"; public HeaderMessage header = new HeaderMessage(); public PolygonMessage polygon = new PolygonMessage(); public PolygonStampedMessage withPolygon(PolygonMessage polygon) { this.polygon = polygon; return this; } public PolygonStampedMessage withHeader(HeaderMessage header) { this.header = header; return this; } } ``` -------------------------------- ### Define Polygon Java Message Class Source: http://portal2.atwebpages.com/jrosclient/Defining_messages.html Implementation of a Java class for the geometry_msgs/Polygon message type using @MessageMetadata. ```java /** Example of custom message definition */ @MessageMetadata( name = PolygonMessage.NAME, /*fields = {"points"} /* This parameter is optional because message has only one field */ md5sum = "cd60a26494a087f577976f0329fa120e") public static class PolygonMessage implements Message { static final String NAME = "geometry_msgs/Polygon"; public Point32Message[] points = new Point32Message[0]; public PolygonMessage withPoints(Point32Message[] points) { this.points = points; return this; } } ``` === COMPLETE CONTENT === This response contains all available snippets from this library. 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