Add robot definition URDF

This enables rviz2 to know where sensors etc are.
None of the data is correct for the raspbot-v2 yet.

robot/Dockerfile

@@ -7,6 +7,7 @@ SHELL ["/bin/bash", "-c"]
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
     python3-colcon-common-extensions \
+    ros-${ROS_DISTRO}-xacro \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /ws
@@ -26,6 +27,9 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     ros-${ROS_DISTRO}-std-msgs \
     ros-${ROS_DISTRO}-sensor-msgs \
     ros-${ROS_DISTRO}-launch-ros \
+    ros-${ROS_DISTRO}-robot-state-publisher \
+    ros-${ROS_DISTRO}-xacro \
+    ros-${ROS_DISTRO}-tf2-ros \
     python3-smbus \
     && rm -rf /var/lib/apt/lists/*
 

robot/src/raspbot_v2/launch/robot.launch.py

@@ -1,10 +1,22 @@
+import os
+
+from ament_index_python.packages import get_package_share_directory
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import LaunchConfiguration, Command
 from launch_ros.actions import Node
+from launch_ros.parameter_descriptions import ParameterValue
 
 
 def generate_launch_description():
+    urdf_file = os.path.join(
+        get_package_share_directory('raspbot_v2'), 'urdf', 'raspbot_v2.urdf.xacro'
+    )
+    robot_description = ParameterValue(
+        Command(['xacro ', urdf_file]),
+        value_type=str,
+    )
+
     return LaunchDescription([
 
         # ── Motor controller arguments ────────────────────────────────────
@@ -23,6 +35,33 @@ def generate_launch_description():
         DeclareLaunchArgument('tilt_center_deg', default_value='60.0',
                               description='Tilt angle at startup and shutdown (degrees)'),
 
+        # ── TF / robot description ────────────────────────────────────────
+        Node(
+            package='robot_state_publisher',
+            executable='robot_state_publisher',
+            name='robot_state_publisher',
+            parameters=[{'robot_description': robot_description}],
+            output='screen',
+        ),
+
+        # Static: map → odom (identity — replace with SLAM/AMCL when ready)
+        Node(
+            package='tf2_ros',
+            executable='static_transform_publisher',
+            name='map_to_odom',
+            arguments=['0', '0', '0', '0', '0', '0', 'map', 'odom'],
+            output='screen',
+        ),
+
+        # Static: odom → base_footprint (placeholder until odometry is added)
+        Node(
+            package='tf2_ros',
+            executable='static_transform_publisher',
+            name='odom_to_base',
+            arguments=['0', '0', '0', '0', '0', '0', 'odom', 'base_footprint'],
+            output='screen',
+        ),
+
         # ── Nodes ─────────────────────────────────────────────────────────
         Node(
             package='raspbot_v2',

robot/src/raspbot_v2/setup.py

@@ -10,6 +10,7 @@ setup(
         ('share/ament_index/resource_index/packages', ['resource/' + package_name]),
         ('share/' + package_name, ['package.xml']),
         ('share/' + package_name + '/launch', ['launch/robot.launch.py']),
+        ('share/' + package_name + '/urdf',   ['urdf/raspbot_v2.urdf.xacro']),
     ],
     install_requires=['setuptools'],
     zip_safe=True,

robot/src/raspbot_v2/urdf/raspbot_v2.urdf.xacro

@@ -0,0 +1,132 @@
+<?xml version="1.0"?>
+<robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="raspbot_v2">
+
+  <!--
+    Physical dimensions — measure your robot and update these.
+    All values in metres.
+  -->
+  <xacro:property name="base_length" value="0.20"/>
+  <xacro:property name="base_width"  value="0.15"/>
+  <xacro:property name="base_height" value="0.06"/>
+
+  <!-- ── Materials ──────────────────────────────────────────────── -->
+  <material name="dark_grey">
+    <color rgba="0.2 0.2 0.2 1.0"/>
+  </material>
+  <material name="light_grey">
+    <color rgba="0.7 0.7 0.7 1.0"/>
+  </material>
+  <material name="blue">
+    <color rgba="0.0 0.4 0.8 1.0"/>
+  </material>
+
+  <!-- ── Base link ──────────────────────────────────────────────── -->
+  <link name="base_link">
+    <visual>
+      <geometry>
+        <box size="${base_length} ${base_width} ${base_height}"/>
+      </geometry>
+      <material name="dark_grey"/>
+    </visual>
+    <collision>
+      <geometry>
+        <box size="${base_length} ${base_width} ${base_height}"/>
+      </geometry>
+    </collision>
+    <inertial>
+      <mass value="1.0"/>
+      <inertia ixx="0.01" ixy="0.0" ixz="0.0"
+               iyy="0.01" iyz="0.0" izz="0.02"/>
+    </inertial>
+  </link>
+
+  <!-- ── Footprint (ground-projected origin) ────────────────────── -->
+  <link name="base_footprint"/>
+  <joint name="base_footprint_joint" type="fixed">
+    <parent link="base_footprint"/>
+    <child  link="base_link"/>
+    <origin xyz="0 0 ${base_height/2}" rpy="0 0 0"/>
+  </joint>
+
+  <!-- ── Lidar ──────────────────────────────────────────────────── -->
+  <!--
+    frame_id published by sllidar_ros2 is "laser".
+    Adjust xyz to where the lidar is mounted on your robot.
+    Typical: top-centre, facing forward.
+  -->
+  <link name="laser">
+    <visual>
+      <geometry><cylinder radius="0.04" length="0.04"/></geometry>
+      <material name="light_grey"/>
+    </visual>
+  </link>
+  <joint name="laser_joint" type="fixed">
+    <parent link="base_link"/>
+    <child  link="laser"/>
+    <!-- Adjust x/y/z: x=forward, y=left, z=up from base_link centre -->
+    <origin xyz="0.0 0.0 0.07" rpy="0 0 0"/>
+  </joint>
+
+  <!-- ── Ultrasonic sensor ──────────────────────────────────────── -->
+  <!--
+    frame_id published by ultrasonic_node is "ultrasonic".
+    Typical: front face of the chassis, pointing forward.
+  -->
+  <link name="ultrasonic">
+    <visual>
+      <geometry><box size="0.02 0.04 0.02"/></geometry>
+      <material name="light_grey"/>
+    </visual>
+  </link>
+  <joint name="ultrasonic_joint" type="fixed">
+    <parent link="base_link"/>
+    <child  link="ultrasonic"/>
+    <!-- Front-centre of the chassis, roughly mid-height -->
+    <origin xyz="${base_length/2} 0.0 0.0" rpy="0 0 0"/>
+  </joint>
+
+  <!-- ── Camera pan/tilt mount ──────────────────────────────────── -->
+  <!--
+    The camera_orientation node publishes joint_states for joints
+    named "pan" and "tilt".  robot_state_publisher will drive these
+    dynamically from that topic.
+  -->
+  <link name="camera_base">
+    <visual>
+      <geometry><box size="0.03 0.03 0.03"/></geometry>
+      <material name="dark_grey"/>
+    </visual>
+  </link>
+  <joint name="camera_base_joint" type="fixed">
+    <parent link="base_link"/>
+    <child  link="camera_base"/>
+    <!-- Top-front of robot; adjust to match servo mount position -->
+    <origin xyz="0.05 0.0 0.06" rpy="0 0 0"/>
+  </joint>
+
+  <!-- Pan joint (yaw, around Z) -->
+  <link name="camera_pan_link"/>
+  <joint name="pan" type="revolute">
+    <parent link="camera_base"/>
+    <child  link="camera_pan_link"/>
+    <axis xyz="0 0 1"/>
+    <origin xyz="0 0 0.015" rpy="0 0 0"/>
+    <limit lower="-1.5708" upper="1.5708" effort="1.0" velocity="1.0"/>
+  </joint>
+
+  <!-- Tilt joint (pitch, around Y) -->
+  <link name="camera_link">
+    <visual>
+      <geometry><box size="0.03 0.06 0.02"/></geometry>
+      <material name="blue"/>
+    </visual>
+  </link>
+  <joint name="tilt" type="revolute">
+    <parent link="camera_pan_link"/>
+    <child  link="camera_link"/>
+    <axis xyz="0 1 0"/>
+    <origin xyz="0.02 0 0" rpy="0 0 0"/>
+    <limit lower="-0.5236" upper="0.9599" effort="1.0" velocity="1.0"/>
+  </joint>
+
+</robot>