Proposal: URML (substrate-neutral robot intent) extends to MCU edge via micro-ROS — the structural bridge

[idoco2003]

Hi @micro-ROS team,

Proposing a URML v0.1 capability-manifest mapping for micro-ROS over micro-ROS/micro_ros_setup. URML (Universal Robot Language, Apache-2.0) is an open spec for substrate-neutral robot intent.

micro-ROS is the structural bridge URML's substrate story needs at the MCU edge. URML's existing reference/ros2-runtime/ adapter composes with full ROS 2 on host-class robots; micro-ROS extends that surface down to MCU-class targets URML's microbit_edu fixture (RFC-0018) and the sibling Move-13 MCU + maker RFCs depend on. The natural composition: URML adapter speaks ROS 2 to a micro-ROS agent on the host, which transports messages to MCU-side ROS 2 nodes via DDS-XRCE — URML's typed primitive vocabulary dispatching onto firmware-class robots with the same adapter pattern URML uses for host-class robots.

This is proposal-only, posted as part of URML's Move #13 outreach (15 engageable RFCs in this wave).

Full RFC: https://github.com/URML-MARS/URML/blob/main/docs/rfcs/0177-micro-ros-outreach.md

Questions worth micro-ROS maintainer input on:

1. MCU-side ROS 2 substrate manifest fields. URML's v0.1 has no substrate.framework: micro_ros declaration. Spec RFC queued. Manifest field expectations from the micro-ROS perspective?
2. Multi-RTOS substrate declaration. Should URML's manifest declare which RTOS (FreeRTOS / NuttX / Zephyr / bare-metal) hosts micro-ROS on the MCU?
3. DDS-XRCE QoS class. Manifest field expectations for resource-constrained QoS profiles?
4. Host-side agent topology. Should URML's manifest declare where the micro-ROS agent runs (companion-computer vs sidecar vs host-process)?
5. Adapter home. URML repo (reference/edu-runtime/MicroRosAdapter or reference/micro-ros-runtime/), micro-ROS-maintained micro-ROS/micro_ros_urml_bridge, or both?
6. Conformance listing. Would the micro-ROS maintainers consider a README link to URML's compatible-runtimes registry once a working adapter ships?
7. Anything else.

Ido Yahalomi (URML maintainer, urml.dev, greenvh@gmail.com)

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AI-assisted prose, maintainer-reviewed before posting (see VIBE.md). Human-only correspondence available on request.