Data Tamer Tools

Tools for working with DataTamer data in ROS2, providing Foxglove integration and MCAP data storage capabilities.

Overview

This package provides five main tools:

• Foxglove Relay: Real-time visualization of DataTamer data through Foxglove Studio
• MCAP Sink: Store DataTamer data in MCAP (MessagePack) format for efficient storage and playback
• MCAP Converter: Convert DataTamer-encoded MCAP files to Protobuf-encoded MCAP files for Foxglove compatibility
• Rosout Logger: Record ROS log messages (/rosout) to MCAP files with Foxglove Log schema
• Log Rotation Coordinator: Synchronize log directory rotation across multiple MCAP loggers

Tools

1. Foxglove Relay (foxglove_relay)

A ROS2 component that bridges DataTamer data to Foxglove Studio for real-time visualization.

Features:

• Automatically discovers DataTamer topics (/data_tamer/schema, /data_tamer/schemas, /data_tamer/snapshot)
• Automatically discovers sensor_msgs/msg/NavSatFix topics and relays each source as its own foxglove.LocationFix channel (Map track)
• Automatically discovers geographic_msgs/msg/GeoPath topics and relays each source as foxglove.GeoJSON (Map overlay)
• Optional MCAP recording of selected Foxglove schemas (foxglove.LocationFix + foxglove.GeoJSON) for offline playback in Foxglove
• Supports both JSON and Protocol Buffers encoding for Foxglove visualization
• Converts DataTamer schemas to JSON Schema or Protocol Buffers descriptor format
• Creates Foxglove WebSocket server for real-time data streaming
• Supports soft eviction of idle channels (closes channels but keeps schemas)
• Configurable eviction policies and discovery intervals
• Optional ROS log relaying to Foxglove

Prerequisites:

• Your DataTamer channels must use DataTamer::ROS2PublisherSink to publish data to ROS2 topics
• The relay automatically discovers and subscribes to the standard DataTamer ROS2 topics

Usage:

# Launch as ROS2 component
ros2 run data_tamer_tools foxglove_relay

# Or with custom parameters
ros2 run data_tamer_tools foxglove_relay --ros-args \
  -p host:=127.0.0.1 \
  -p port:=8765 \
  -p use_protobuf:=true \
  -p eviction_ttl_sec:=900 \
  -p eviction_period_sec:=30 \
  -p discovery_sec:=5 \
  -p enable_rosout:=true

Parameters:

WebSocket Server Configuration:

• host (string, default: “127.0.0.1”): WebSocket server host address
• port (int, default: 8765): WebSocket server port number

Data Encoding:

• use_protobuf (bool, default: true): Use Protocol Buffers encoding instead of JSON
  • true: Data is serialized using Protocol Buffers for better performance and smaller payloads
  • false: Data is serialized as JSON strings for human readability

Channel Management:

• eviction_ttl_sec (int, default: 900): Time-to-live for idle channels in seconds
  • Channels that haven’t received data for this duration will be soft-evicted (closed but schema kept)
• eviction_period_sec (int, default: 30): Interval in seconds for checking stale channels
  • How often the relay checks for channels that should be evicted
• discovery_sec (int, default: 5): Interval in seconds for topic discovery
  • How often the relay scans for new DataTamer topics to subscribe to
• navsat_ttl_sec (int, default: 30): Time-to-live for NavSatFix sources; stale sources are pruned from the relay’s discovered LocationFix tracks
• geopath_ttl_sec (int, default: 0): Time-to-live for GeoPath sources (0 disables pruning)
• navsat_qos (string, default: “sensor”): QoS profile for NavSatFix subscriptions. Accepts sensor (or sensor_data), system_default (or default), best_effort, or reliable.
• location_fix_prefix (string, default: “/locations”): Prefix for relayed per-source foxglove.LocationFix topics
• geojson_prefix (string, default: “/geojson”): Prefix for relayed per-source foxglove.GeoJSON topics

Map Topic Mapping:

• A discovered sensor_msgs/msg/NavSatFix topic like /gps/fix is relayed as a per-source foxglove.LocationFix topic at /locations/gps/fix (prefix is configurable via location_fix_prefix)
• A discovered geographic_msgs/msg/GeoPath topic like /planner/path is relayed as foxglove.GeoJSON at /geojson/planner/path (prefix is configurable via geojson_prefix)
• Each GeoPath is rendered as GeoJSON (FeatureCollection) containing a LineString for the path and Point features for start/goal; colors are deterministic per topic

Relay MCAP Recording (Foxglove schemas only):

• enable_mcap (bool, default: false): Record foxglove.LocationFix + foxglove.GeoJSON to an MCAP file
• logdir (string, default: “.”): Directory for the initial relay MCAP file
• mcap_filename (string, default: “foxglove_relay.mcap”): Relay MCAP filename
• mcap_append_timestamp (bool, default: true): Prefix timestamp like YYYY-MM-DD_HH-MM-SS_ to the relay MCAP filename
• mcap_profile (string, default: “protobuf”): MCAP profile string passed to the Foxglove SDK writer
• mcap_truncate (bool, default: false): If true, overwrite an existing relay MCAP file on name collision
• mcap_use_chunks (bool, default: true): Enable chunking (batch writes) in the relay MCAP output
• mcap_chunk_size (int, default: 0): Chunk size in bytes (0 = SDK default)
• mcap_compression (string, default: “zstd”): Compression type: none, zstd, or lz4
• rotate_dir_topic (string, default: “”): Rotation topic override (empty = auto-discover data_tamer_tools/msg/LogDir by type)

ROS Log Integration:

• enable_rosout (bool, default: true): Enable relaying of ROS logs to Foxglove
  • true: ROS logs from /rosout topic are relayed to Foxglove Log channel
  • false: Disable ROS log relaying
• rosout_topic (string, default: “/rosout”): ROS topic name for log messages

Foxglove Studio Connection (Live):

1. Open Foxglove Studio

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