[TASK] Acoustic Modem

[forrisdahl]

Description

Develop a ROS 2 Humble interface for the Waterlinked Acoustic Modem. The node shall provide a bridge between ROS 2 and the modem hardware (serial/Ethernet), enabling data transmission, reception, and optional ranging functionality. The interface should expose modem functionality via ROS topics, services, and actions with clear message definitions for integration into the main AUV control system.

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Requirements

• Data Transmission

  • Provide an action/service to send binary payloads to a remote modem.
  • Support acknowledgments, retries, and configurable timeouts.
  • Handle payload fragmentation if larger than the modem MTU.

• Data Reception

  • Publish received messages (with source ID, RSSI, SNR, timestamp) on a dedicated topic.
  • Support configurable QoS settings for reliability and buffer depth.

• Ranging (if supported by hardware)

  • Expose an action/service to trigger a range request to a peer modem.
  • Publish range results (distance, RTT, confidence/quality metrics).

• Status & Diagnostics

  • Publish link and modem health information (noise floor, temperature, supply voltage, queue fill, duty cycle).
  • Expose diagnostics in a standard ROS 2 format (diagnostic_msgs/DiagnosticArray).

• Configuration & Parameters

  • ROS 2 parameters for modem ID, port (serial/Ethernet), baud rate, MTU size, default timeouts, duty cycle limits, and peer table.
  • YAML-based parameter file for deployment configuration.

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Acceptance Criteria

• Modem can send and receive packets through ROS 2 with correct message formatting.
• Ranging requests (if supported) return consistent and validated results.
• Status and diagnostic topics update at the specified interval and reflect real hardware conditions.
• Parameters can be configured via ROS 2 launch files and dynamically reloaded.
• All custom messages, services, and actions are properly defined and documented.
• Interface is tested with real hardware and validated in-water communication trials.

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To-Do Checklist

• Research Waterlinked modem API (serial/Ethernet commands and capabilities).
• Define ROS 2 message/service/action definitions (Packet, LinkStatus, RangeReport, SendPacket).
• Implement driver node for modem communication (RX/TX handling, queue management, retries).
• Implement status and diagnostics publisher.
• Add parameter handling (modem ID, timeouts, MTU, etc.).
• Test interface with simulated data.
• Validate functionality with physical modem hardware.
• Document message definitions, parameters, and usage in README.

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Contacts

• @forrisdahl

Do you want me to also include a proposed package structure (e.g. msg/, srv/, action/, launch/, config/) like I did in the modem interface spec, or just keep the issue at this higher-level scope?