# RM75 CANFD UDP Feedback Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Replace synchronous TCP joint polling with the vendor UDP realtime callback while making YAML the source of robot behavior and hardware defaults.

**Architecture:** Keep one `RoboticArm(RM_TRIPLE_MODE_E)` handle per arm. TCP sends CANFD and safety/tool commands; a 5 ms controller UDP push invokes a minimal callback that updates the existing locked joint snapshot. Launch keeps only topology, mock safety mode, PICO input, and generated paths/topics.

**Tech Stack:** Python 3.10, ROS2 Humble, RealMan Python API2, YAML, pytest, colcon

---

### Task 1: Add failing UDP feedback adapter tests

**Files:**
- Modify: `xr_rm_teleop/test/test_initial_joint_pose.py`

- [ ] **Step 1: Replace polling-specific tests with UDP callback tests**

Add `sys`, `types`, and `SimpleNamespace` imports. Replace
`test_joint_feedback_is_cached_in_radians` and
`test_feedback_loop_uses_absolute_schedule_without_catch_up` with helpers and
tests equivalent to:

```python
def _udp_state(robot_ip="127.0.0.1", joints=None, error_code=0):
    return SimpleNamespace(
        errCode=error_code,
        arm_ip=robot_ip.encode(),
        joint_status=SimpleNamespace(
            joint_position=joints or [0.0, 10.0, -20.0, 30.0, -40.0, 50.0, -60.0]
        ),
    )


def test_udp_feedback_is_cached_in_radians(monkeypatch) -> None:
    monotonic = iter([10.0, 10.005])
    monkeypatch.setattr(realman_adapter.time, "monotonic", lambda: next(monotonic))
    adapter = RealManAdapter(
        "127.0.0.1",
        8080,
        0,
        "127.0.0.1",
        8090,
    )

    adapter._accept_realtime_feedback = True
    adapter._on_realtime_arm_state(_udp_state())
    first = adapter.get_latest_joint_state()
    adapter._on_realtime_arm_state(_udp_state())
    second = adapter.get_latest_joint_state()

    assert first is not None
    assert first.positions == pytest.approx(
        [math.radians(value) for value in [0, 10, -20, 30, -40, 50, -60]]
    )
    assert first.read_duration_ms is None
    assert first.update_interval_ms is None
    assert second is not None
    assert second.update_interval_ms == pytest.approx(5.0)


@pytest.mark.parametrize(
    "state",
    [
        _udp_state(error_code=-3),
        _udp_state(robot_ip="192.168.192.18"),
        _udp_state(joints=[0.0] * 6),
        _udp_state(joints=[0.0, 0.0, 0.0, math.nan, 0.0, 0.0, 0.0]),
    ],
)
def test_invalid_udp_feedback_does_not_replace_snapshot(state) -> None:
    adapter = RealManAdapter(
        "127.0.0.1",
        8080,
        0,
        "127.0.0.1",
        8090,
    )
    adapter._accept_realtime_feedback = True
    adapter._on_realtime_arm_state(_udp_state(joints=[1.0] * 7))
    before = adapter.get_latest_joint_state()

    adapter._on_realtime_arm_state(state)

    assert adapter.get_latest_joint_state() == before
```

Add a fake vendor module that records callback registration and push config.
Its `rm_set_realtime_push()` invokes the registered callback with `_udp_state()`.
Assert:

```python
adapter.connect()
arm = fake_module.RoboticArm.instance
assert arm.config.args == (5, True, 8090, 0, "192.168.192.148")
assert arm.callback is adapter._realtime_callback
assert adapter.get_latest_joint_state() is not None
assert not hasattr(adapter, "_feedback_thread")
```

Add failure cases where `rm_set_realtime_push()` returns `1`, and where
`adapter._feedback_ready.wait` returns `False`. Both must raise `RuntimeError`;
the fake arm must record one `rm_delete_robot_arm()` call.

- [ ] **Step 2: Run the focused tests and verify RED**

Run:

```bash
cd /home/robot/WS_xr
source /opt/ros/humble/setup.bash
python3 -m pytest -q src/xr_rm_teleop/test/test_initial_joint_pose.py
```

Expected: FAIL because `RealManAdapter` does not accept realtime push
parameters and has no `_on_realtime_arm_state`.

---

### Task 2: Implement single-handle UDP feedback

**Files:**
- Modify: `xr_rm_teleop/xr_rm_teleop/realman_adapter.py`
- Modify: `xr_rm_teleop/xr_rm_teleop/single_arm_velocity_teleop.py`
- Modify: `xr_rm_teleop/test/test_initial_joint_pose.py`

- [ ] **Step 1: Replace polling constructor state with realtime push state**

Change `RealManAdapter.__init__` positional parameters from `feedback_period`
to:

```python
realtime_push_host_ip: str,
realtime_push_port: int,
realtime_push_cycle_ms: int = 5,
```

Validate with stdlib `ipaddress.IPv4Address`:

```python
try:
    self._realtime_push_host_ip = str(
        ipaddress.IPv4Address(realtime_push_host_ip)
    )
except ipaddress.AddressValueError as exc:
    raise ValueError("realtime_push_host_ip must be a valid IPv4 address") from exc
if not 1 <= realtime_push_port <= 65535:
    raise ValueError("realtime_push_port must be between 1 and 65535")
if realtime_push_cycle_ms <= 0 or realtime_push_cycle_ms % 5 != 0:
    raise ValueError("realtime_push_cycle_ms must be a positive multiple of 5")
```

Store the port and cycle, then replace feedback thread members with:

```python
self._feedback_ready = threading.Event()
self._realtime_callback: Any | None = None
self._accept_realtime_feedback = False
self._feedback_fault_logged = False
```

- [ ] **Step 2: Configure callback and UDP push during connect**

Import these SDK symbols inside `connect()` so mock mode stays SDK-free:

```python
from Robotic_Arm.rm_robot_interface import (
    RoboticArm,
    rm_realtime_arm_state_callback_ptr,
    rm_realtime_push_config_t,
    rm_thread_mode_e,
)
```

After existing safety and optional initial-pose configuration:

```python
self._feedback_ready.clear()
self._accept_realtime_feedback = True
self._realtime_callback = rm_realtime_arm_state_callback_ptr(
    self._on_realtime_arm_state
)
self._arm.rm_realtime_arm_state_call_back(self._realtime_callback)
config = rm_realtime_push_config_t(
    self._realtime_push_cycle_ms,
    True,
    self._realtime_push_port,
    0,
    self._realtime_push_host_ip,
)
self._check_return(
    self._arm.rm_set_realtime_push(config),
    "rm_set_realtime_push",
)
if not self._feedback_ready.wait(timeout=2.0):
    raise RuntimeError(
        "RealMan UDP realtime feedback did not receive a valid frame within 2 seconds"
    )
```

Wrap post-handle initialization so any exception disables callback acceptance,
deletes the handle, sets `_arm = None`, and re-raises.

- [ ] **Step 3: Implement the bounded callback**

Replace `_feedback_loop()` and `_read_joint_state_once()` with:

```python
def _on_realtime_arm_state(self, data: Any) -> None:
    if not self._accept_realtime_feedback:
        return
    try:
        if data is None or int(data.errCode) != 0:
            raise ValueError("invalid realtime feedback error code")
        arm_ip = data.arm_ip
        if isinstance(arm_ip, bytes):
            arm_ip = arm_ip.decode("utf-8").split("\x00", 1)[0]
        if str(arm_ip) != self._robot_ip:
            raise ValueError(f"unexpected realtime feedback source: {arm_ip}")
        degrees = list(data.joint_status.joint_position)
        if (
            len(degrees) != 7
            or not all(isinstance(value, Number) for value in degrees)
        ):
            raise ValueError("RM75 UDP feedback must contain 7 numeric joints")
        positions = [math.radians(float(value)) for value in degrees]
        if not all(math.isfinite(value) for value in positions):
            raise ValueError("RM75 UDP feedback contains NaN/Inf")
        received_at = time.monotonic()
        with self._joint_state_lock:
            update_interval_ms = (
                None
                if self._latest_joint_state is None
                else (received_at - self._latest_joint_state.received_at) * 1000.0
            )
            self._latest_joint_state = JointStateSnapshot(
                positions,
                received_at,
                None,
                update_interval_ms,
            )
        self._feedback_fault_logged = False
        self._feedback_ready.set()
    except Exception as exc:
        if not self._feedback_fault_logged:
            self._log_warn(f"RealMan UDP realtime feedback invalid: {exc}")
            self._feedback_fault_logged = True
```

In `close()`, set `_accept_realtime_feedback = False` before slow-stop and
handle deletion. Remove feedback thread stop/join logic. Keep the callback
reference alive until after `rm_delete_robot_arm()`.

- [ ] **Step 4: Declare and pass ROS parameters**

In `SingleArmVelocityTeleop`, declare:

```python
self.declare_parameter("realtime_push_host_ip", "")
self.declare_parameter("realtime_push_port", 0)
self.declare_parameter("realtime_push_cycle_ms", 5)
```

Replace `feedback_period=self._dt` in `_make_adapter()` with:

```python
realtime_push_host_ip=str(
    self.get_parameter("realtime_push_host_ip").value
),
realtime_push_port=int(
    self.get_parameter("realtime_push_port").value
),
realtime_push_cycle_ms=int(
    self.get_parameter("realtime_push_cycle_ms").value
),
```

Update all direct `RealManAdapter(...)` calls in tests to pass a host and port.

- [ ] **Step 5: Run focused tests and verify GREEN**

Run:

```bash
cd /home/robot/WS_xr
source /opt/ros/humble/setup.bash
python3 -m pytest -q src/xr_rm_teleop/test/test_initial_joint_pose.py
```

Expected: all focused tests pass, with no real SDK connection.

---

### Task 3: Move robot defaults into YAML and simplify launch

**Files:**
- Modify: `xr_rm_bringup/config/right_arm_rm75.yaml`
- Modify: `xr_rm_bringup/config/left_arm_rm75.yaml`
- Modify: `xr_rm_bringup/config/dual_arm_rm75.yaml`
- Modify: `xr_rm_bringup/launch/arm_debug.launch.py`

- [ ] **Step 1: Run a failing ownership assertion**

Run a one-off Python assertion that requires the three YAMLs to contain UDP
and tool parameters, and requires launch not to declare robot behavior
arguments:

```python
from pathlib import Path
import yaml

config_dir = Path("xr_rm_bringup/config")
for name in ("left_arm_rm75.yaml", "right_arm_rm75.yaml"):
    params = yaml.safe_load((config_dir / name).read_text())
    params = params["single_arm_velocity_teleop"]["ros__parameters"]
    assert "use_mock" not in params
    assert params["realtime_push_host_ip"] == "192.168.192.148"
    assert params["realtime_push_cycle_ms"] == 5
    assert params["enable_tool_control"] is True

source = Path("xr_rm_bringup/launch/arm_debug.launch.py").read_text()
for name in (
    "left_robot_ip",
    "right_robot_ip",
    "robot_port",
    "avoid_singularity",
    "control_rate_hz",
    "follow",
    "configure_safety_limits",
    "move_to_initial_pose_on_connect",
):
    assert f'DeclareLaunchArgument("{name}"' not in source
```

Expected: FAIL because the YAML parameters are missing and launch still
declares overrides.

- [ ] **Step 2: Update all YAML nodes**

Remove `use_mock`. Add:

```yaml
realtime_push_host_ip: 192.168.192.148
realtime_push_cycle_ms: 5
enable_tool_control: true
enable_trigger_gripper_control: true
trigger_close_threshold: 0.95
configure_peripheral_on_connect: true
```

Use `realtime_push_port: 8089` for left-arm nodes and `8090` for right-arm
nodes. Keep:

```yaml
# all single-arm and dual-arm nodes
follow: false
canfd_trajectory_mode: 2
```

The right-arm high-follow default was reverted after the first hardware test
exposed an unplanned stationary null-space trajectory. Do not change speeds,
workspace limits, timeouts, safety limits, or initial pose defaults.

- [ ] **Step 3: Reduce launch overrides**

Make `_single_arm_node(arm, use_mock)` and `_dual_arm_nodes(use_mock)` load
their YAML first, then pass only:

```python
{
    "use_mock": use_mock,
    "robot_urdf_path": _rm75_urdf(),
    "peripheral_config_file": _config_file("peripherals_rm75.yaml"),
    "peripheral_arm": arm,
    "tool_command_topic": f"/xr_rm/{_arm_name(arm)}/tool_enable",
}
```

Keep equivalent per-side generated values in dual mode. Remove
`_initial_pose_override`, robot IP/port, avoid-singularity, control-rate,
follow, safety, tool-control and initial-pose parsing from `_launch_setup`.

Keep only these launch arguments:

```python
DeclareLaunchArgument("arm", default_value="right")
DeclareLaunchArgument("use_mock", default_value="true")
DeclareLaunchArgument("udp_host", default_value="0.0.0.0")
DeclareLaunchArgument("udp_port", default_value="15000")
DeclareLaunchArgument("udp_timer_hz", default_value="200.0")
```

- [ ] **Step 4: Re-run ownership assertion and inspect launch arguments**

Run the assertion from Step 1, then:

```bash
cd /home/robot/WS_xr
source /opt/ros/humble/setup.bash
source install/setup.bash
ros2 launch xr_rm_bringup arm_debug.launch.py --show-args
```

Expected: the assertion passes; launch lists only `arm`, `use_mock`,
`udp_host`, `udp_port`, and `udp_timer_hz`.

---

### Task 4: Synchronize launcher UI and README

**Files:**
- Modify: `xr_rm_bringup/tools/launcher_ui.py`
- Modify: `README.md`

- [ ] **Step 1: Remove deleted launch arguments from UI commands**

Keep ping targets unchanged. Change real launch commands to:

```python
"ros2 launch xr_rm_bringup arm_debug.launch.py arm:=left use_mock:=false"
"ros2 launch xr_rm_bringup arm_debug.launch.py arm:=right use_mock:=false"
"ros2 launch xr_rm_bringup arm_debug.launch.py arm:=both use_mock:=false"
```

- [ ] **Step 2: Update README ownership and commands**

Remove examples and launch-argument descriptions for robot IP/port,
avoid-singularity, control-rate, follow, safety/tool flags, and initial-pose
overrides. State that these values live in the selected YAML. Add the UDP
feedback parameters, host `192.168.192.148`, ports `8089/8090`, 5 ms cycle,
and the command used after Wi-Fi changes:

```bash
ip -4 route get 192.168.192.19
```

Keep `arm`, `use_mock`, and PICO UDP arguments documented as launch
arguments. Keep the warning that checked-in default `use_mock=true` prevents
an accidental real connection.

- [ ] **Step 3: Check syntax and stale references**

Run:

```bash
python3 -m py_compile \
  xr_rm_bringup/launch/arm_debug.launch.py \
  xr_rm_bringup/tools/launcher_ui.py
rg -n "left_robot_ip:=|right_robot_ip:=|move_to_initial_pose_on_connect:=" \
  README.md xr_rm_bringup/tools/launcher_ui.py
```

Expected: compilation passes; `rg` returns no stale command-line overrides.

---

### Task 5: Full verification

**Files:**
- Verify all files changed by Tasks 1–4

- [ ] **Step 1: Run teleop tests**

```bash
cd /home/robot/WS_xr
source /opt/ros/humble/setup.bash
python3 -m pytest -q src/xr_rm_teleop/test
python3 -m pytest -q src/xr_rm_teleop/test/test_orientation_control.py
```

Expected: all tests pass.

- [ ] **Step 2: Build all workspace packages**

```bash
cd /home/robot/WS_xr
source /opt/ros/humble/setup.bash
colcon build --symlink-install --executor sequential
```

Expected: `xr_rm_interfaces`, `xr_rm_input`, `xr_rm_teleop`, and
`xr_rm_bringup` all finish successfully.

- [ ] **Step 3: Verify mock launch without vendor hardware**

```bash
cd /home/robot/WS_xr
source /opt/ros/humble/setup.bash
source install/setup.bash
timeout 8s ros2 launch xr_rm_bringup arm_debug.launch.py \
  arm:=right use_mock:=true
```

Expected: the mock teleop and UDP input nodes start; timeout ends the launch.
No RealMan SDK connection is attempted.

- [ ] **Step 4: Inspect final diff**

```bash
cd /home/robot/WS_xr/src
git diff --check
git status --short
git diff --stat
```

Expected: no whitespace errors and no unrelated files. Do not commit, push,
or connect to the real robot unless the user explicitly requests it.