First step to supporting GLTF

Examples/BB2B/BB2B.cs

@@ -11,9 +11,8 @@ namespace RoboidControl {
 
         public BB2B(Participant owner) : base(owner) {
             this.name = "BB2B";
+            this.SetMotors(new Motor(this), new Motor(this));
             this.SetDriveDimensions(0.064f, 0.128f);
-            // this.wheelRadius = 0.032f;
-            // this.wheelSeparation = 0.128f;
 
             // Is has a touch sensor at the front left of the roboid
             touchLeft = new(this) {

Examples/BB2B/BB2B_Encoder.cs

@@ -0,0 +1,55 @@
+using LinearAlgebra;
+
+namespace RoboidControl {
+
+    // The robot is based on a differential drive
+    public class BB2B_Encoder : DifferentialDrive {
+        readonly DifferentialDrive drive;
+        readonly TouchSensor touchLeft;
+        readonly TouchSensor touchRight;
+        const float speed = 180.0f; // wheel rotation speed in degrees
+
+        public BB2B_Encoder(Participant owner) : base(owner) {
+            this.name = "BB2B";
+            this.SetDriveDimensions(0.064f, 0.128f);
+
+            // Update the basic motors to motors with encoder
+            EncoderMotor leftMotor = new(this, new RelativeEncoder()) {
+                position = new Spherical(0.064f, Direction.left)
+            };
+            EncoderMotor rightMotor = new(this, new RelativeEncoder()) {
+                position = new Spherical(0.064f, Direction.right)
+            };
+            this.SetMotors(leftMotor, rightMotor);
+
+            // Is has a touch sensor at the front left of the roboid
+            touchLeft = new(this) {
+                position = Spherical.Degrees(0.12f, -30, 0),
+                orientation = new SwingTwist(-30, 0, 0)
+            };
+            touchRight = new(this) {
+                position = Spherical.Degrees(0.12f, 30, 0),
+                orientation = new SwingTwist(30, 0, 0)
+            };
+        }
+
+        public override void Update(ulong currentTimeMs, bool recurse = true) {
+
+            // The left wheel turns forward when nothing is touched on the right side
+            // and turn backward when the roboid hits something on the right
+            float leftWheelVelocity = touchRight.touchedSomething ? -speed : speed;
+
+            // The right wheel does the same, but instead is controlled by
+            // touches on the left side
+            float rightWheelVelocity = touchLeft.touchedSomething ? -speed : speed;
+
+            // When both sides are touching something, both wheels will turn backward
+            // and the roboid will move backwards
+
+            this.SetWheelAngularVelocity(leftWheelVelocity, rightWheelVelocity);
+
+            base.Update(currentTimeMs, recurse);
+        }
+    }
+
+}

Unity/DifferentialDrive.cs

@@ -2,71 +2,110 @@
 using UnityEngine;
 
 namespace RoboidControl.Unity {
+
+    /// <summary>
+    /// The Unity representation of a Roboid Control differential drive
+    /// </summary>
     public class DifferentialDrive : Thing {
 
-        public Wheel leftWheel;
-        public Wheel rightWheel;
-        public SphereCollider casterWheel;
-
-        protected RoboidControl.DifferentialDrive coreDrive => core as RoboidControl.DifferentialDrive;
+        /// <summary>
+        /// The core differential drive
+        /// </summary>
+        public RoboidControl.DifferentialDrive coreDrive => core as RoboidControl.DifferentialDrive;
 
         /// <summary>
         /// Create the Unity representation
         /// </summary>
-        /// <param name="core">The core touch sensor</param>
+        /// <param name="coreDrive">The core touch sensor</param>
         /// <returns>The Unity representation of the touch sensor</returns>
-        public static DifferentialDrive Create(RoboidControl.DifferentialDrive core) {
-            DifferentialDrive component = null;
-            Rigidbody rb = null;
+        /// This uses a 'DifferentialDrive' resource when available for the Unity representation.
+        /// If this is not available, a default representation is created.
+        public static DifferentialDrive Create(RoboidControl.DifferentialDrive coreDrive) {
+            DifferentialDrive differentialDrive;
             GameObject prefab = (GameObject)Resources.Load("DifferentialDrive");
             if (prefab != null) {
                 // Use resource prefab when available
                 GameObject gameObj = Instantiate(prefab);
-                component = gameObj.GetComponent<DifferentialDrive>();
-                if (component != null)
-                    component.core = core;
-
-                rb = component.GetComponent<Rigidbody>();
+                differentialDrive = gameObj.GetComponent<DifferentialDrive>();
+                differentialDrive.Init(coreDrive);
             }
             else {
-                // Fallback implementation
-                GameObject gameObj = new(core.name);
-                component = gameObj.AddComponent<DifferentialDrive>();
-                component.Init(core);
+                // Default implementation
+                GameObject gameObj = new(coreDrive.name);
+                differentialDrive = gameObj.AddComponent<DifferentialDrive>();
+                differentialDrive.Init(coreDrive);
 
-                rb = gameObj.AddComponent<Rigidbody>();
+                Rigidbody rb = gameObj.AddComponent<Rigidbody>();
                 rb.isKinematic = false;
                 rb.mass = 0.1f;
             }
-            return component;
+            return differentialDrive;
         }
 
+        /// <summary>
+        /// The left wheel of the differential drive
+        /// </summary>
+        public Wheel leftWheel;
+        /// <summary>
+        /// The right wheel of the differential drive
+        /// </summary>
+        public Wheel rightWheel;
+        /// <summary>
+        /// The caster wheel to keep the differential drive horizontal
+        /// </summary>
+        public SphereCollider casterWheel;
+
+        /// <summary>
+        /// The rigidbody of the differential drive
+        /// </summary>
         private Rigidbody rb = null;
 
+        /// <summary>
+        /// Start the Unity representation
+        /// </summary>
         protected virtual void Start() {
             rb = GetComponent<Rigidbody>();
         }
 
+        /// <summary>
+        /// Handle the binary event indicating a configuration change
+        /// </summary>
         protected override void HandleBinary() {
-            Debug.Log("Diff drive handle Binary");
-            if (coreDrive.wheelRadius <= 0 || coreDrive.wheelSeparation <= 0)
+            // Ignore it when the wheel radius is not set
+            if (coreDrive.wheelRadius <= 0)
                 return;
 
-            if (leftWheel == null)
+            // Destroy any (generic) thing with the same id
+            if (leftWheel == null) {
+                Thing[] things = FindObjectsOfType<Thing>();
+                foreach (Thing thing in things) {
+                    if (thing.core.id == coreDrive.leftWheel.id)
+                        Destroy(thing.gameObject);
+                }
+            }
+            if (leftWheel == null && coreDrive.leftWheel != null)
                 leftWheel = Wheel.Create(this.transform, coreDrive.leftWheel.id);
+            if (leftWheel != null) {
+                leftWheel.core ??= coreDrive.leftWheel;
+                SphereCollider leftWheelCollider = leftWheel.GetComponent<SphereCollider>();
+                leftWheelCollider.radius = coreDrive.wheelRadius;
+            }
 
-            leftWheel.core ??= coreDrive.leftWheel;
-            SphereCollider leftWheelCollider = leftWheel.GetComponent<SphereCollider>();
-            leftWheelCollider.radius = coreDrive.wheelRadius;
-            // leftWheelCollider.center = new Vector3(-coreDrive.wheelSeparation / 2, 0, 0);
-
-            if (rightWheel == null)
+            // Destroy any (generic) thing with the same id
+            if (rightWheel == null) {
+                Thing[] things = FindObjectsOfType<Thing>();
+                foreach (Thing thing in things) {
+                    if (thing.core.id == coreDrive.rightWheel.id)
+                        Destroy(thing.gameObject);
+                }
+            }
+            if (rightWheel == null && coreDrive.rightWheel != null)
                 rightWheel = Wheel.Create(this.transform, coreDrive.rightWheel.id);
-
-            rightWheel.core ??= coreDrive.rightWheel;
-            SphereCollider rightWheelCollider = rightWheel.GetComponent<SphereCollider>();
-            rightWheelCollider.radius = coreDrive.wheelRadius;
-            // rightWheelCollider.center = new Vector3(coreDrive.wheelSeparation / 2, 0, 0);
+            if (rightWheel != null) {
+                rightWheel.core ??= coreDrive.rightWheel;
+                SphereCollider rightWheelCollider = rightWheel.GetComponent<SphereCollider>();
+                rightWheelCollider.radius = coreDrive.wheelRadius;
+            }
 
             if (casterWheel == null) {
                 GameObject gameObj = new("Caster wheel");
@@ -76,9 +115,14 @@ namespace RoboidControl.Unity {
             }
             casterWheel.radius = coreDrive.wheelRadius;
             // Put it in the middle of the back
-            casterWheel.center = new Vector3(0, 0, -coreDrive.wheelSeparation);
+            // This code assumes that the left wheel position has Direction.left and the right wheel Direction.right...
+            float wheelSeparation = coreDrive.leftWheel.position.distance + coreDrive.rightWheel.position.distance;
+            casterWheel.center = new Vector3(0, 0, -wheelSeparation);
         }
 
+        /// <summary>
+        /// Update the Unity representation state
+        /// </summary>
         protected override void FixedUpdate() {
             base.FixedUpdate();
 
@@ -86,8 +130,10 @@ namespace RoboidControl.Unity {
                 float leftWheelVelocity = leftWheel.rotationSpeed * (2 * Mathf.PI) * coreDrive.wheelRadius;
                 float rightWheelVelocity = rightWheel.rotationSpeed * (2 * Mathf.PI) * coreDrive.wheelRadius;
 
+                // This code assumes that the left wheel position has Direction.left and the right wheel Direction.right...
+                float wheelSeparation = coreDrive.leftWheel.position.distance + coreDrive.rightWheel.position.distance;
                 float forwardSpeed = (leftWheelVelocity + rightWheelVelocity) / 2f;
-                float turningSpeed = (leftWheelVelocity - rightWheelVelocity) / coreDrive.wheelSeparation;
+                float turningSpeed = (leftWheelVelocity - rightWheelVelocity) / wheelSeparation;
 
                 // Use smoothing to emulate motor inertia
                 rb.velocity = 0.9f * rb.velocity + 0.1f * forwardSpeed * transform.forward;

Unity/DistanceSensor.cs

@@ -5,42 +5,45 @@ using UnityEngine;
 namespace RoboidControl.Unity {
 
     /// <summary>
-    /// The Unity representation of a distance sensor
+    /// The Unity representation of a Roboid Control distance sensor
     /// </summary>
     public class DistanceSensor : Thing {
 
         /// <summary>
         /// The core distance sensor
         /// </summary>
-        public new RoboidControl.DistanceSensor core {
-            get => (RoboidControl.DistanceSensor)base.core;
-            set => base.core = value;
-        }
+        public RoboidControl.DistanceSensor coreSensor => base.core as RoboidControl.DistanceSensor;
 
         /// <summary>
         /// Start the Unity representation
         /// </summary>
         protected virtual void Start() {
-            if (core == null) {
-                SiteServer siteServer = FindAnyObjectByType<SiteServer>();
-                SetCoreThing(new RoboidControl.DistanceSensor(siteServer.site));
-            }
-
             StartCoroutine(MeasureDistance());
         }
 
         /// <summary>
         /// Create the Unity representation of the distance sensor
         /// </summary>
-        /// <param name="parent">The parent of the core distance sensor</param>
+		/// <param name="core">The core distance sensor</param>
         /// <returns>The Unity representation of the distance sensor</returns>
-        public static DistanceSensor Create(RoboidControl.DistanceSensor core) {
-            GameObject distanceObj = new("Distance sensor");
-            DistanceSensor component = distanceObj.AddComponent<DistanceSensor>();
-            if (core.parent != null && core.parent.component != null)
-                distanceObj.transform.SetParent(core.parent.component.transform, false);
-
-            return component;
+        /// This uses a 'DistanceSensor' resource when available for the Unity representation.
+        /// If this is not available, a default representation is created.
+        public static DistanceSensor Create(RoboidControl.DistanceSensor coreSensor) {
+            DistanceSensor distanceSensor;
+            GameObject prefab = (GameObject)Resources.Load("DistanceSensor");
+            if (prefab != null) {
+                // Use resource prefab when available
+                GameObject gameObj = Instantiate(prefab);
+                distanceSensor = gameObj.GetComponent<DistanceSensor>();
+                distanceSensor.Init(coreSensor);
+            }
+            else {
+                // Default implementation
+                GameObject distanceObj = new(coreSensor.name);
+                distanceSensor = distanceObj.AddComponent<DistanceSensor>();
+                distanceSensor.Init(coreSensor);
+            }
+            return distanceSensor;
         }
 
         /// <summary>
@@ -53,10 +56,10 @@ namespace RoboidControl.Unity {
                     Thing thing = hitInfo.transform.GetComponentInParent<Thing>();
                     if (thing == null) {
                         // Debug.Log($"collision {hitInfo.transform.name} {hitInfo.distance}");
-                        core.distance = hitInfo.distance;
+                        coreSensor.distance = hitInfo.distance;
                     }
                     else
-                        core.distance = 0;
+                        coreSensor.distance = 0;
                 }
                 yield return new WaitForSeconds(0.1f);
             }

Unity/Motor.cs

@@ -2,50 +2,73 @@
 using UnityEngine;
 
 namespace RoboidControl.Unity {
+    /// <summary>
+    /// The Unity representation of a Roboid Control motor
+    /// </summary>
     public class Motor : Thing {
 
-        public float maxSpeed = 5;
         /// <summary>
-        /// Create the Unity representation
+        /// The core motor
         /// </summary>
-        /// <param name="core">The core motor</param>
+        public RoboidControl.Motor coreMotor => base.core as RoboidControl.Motor;
+
+        /// <summary>
+        /// Create the Unity representation of the motor
+        /// </summary>
+        /// <param name="coreMotor">The core motor</param>
         /// <returns>The Unity representation of a motor</returns>
-        public static Motor Create(RoboidControl.Motor core) {
+		/// This uses a 'Motor' resource when available for the Unity representation.
+		/// If this is not available, a default representation is created.
+        public static Motor Create(RoboidControl.Motor coreMotor) {
+            Motor motor;
             GameObject prefab = (GameObject)Resources.Load("Motor");
             if (prefab != null) {
                 // Use resource prefab when available
                 GameObject gameObj = Instantiate(prefab);
-                Motor component = gameObj.GetComponent<Motor>();
-                if (component != null)
-                    component.core = core;
-                return component;
+                motor = gameObj.GetComponent<Motor>();
+                motor.Init(coreMotor);
             }
             else {
-                // Fallback implementation
-                GameObject gameObj = new(core.name);
-                Motor component = gameObj.AddComponent<Motor>();
-                component.Init(core);
+                // Default implementation
+                GameObject gameObj = new(coreMotor.name);
+                motor = gameObj.AddComponent<Motor>();
+                motor.Init(coreMotor);
 
                 Rigidbody rb = gameObj.AddComponent<Rigidbody>();
                 rb.isKinematic = true;
-                return component;
             }
+            return motor;
         }
 
-        public float rotationSpeed = 0.0f;
+        /// <summary>
+        /// The maximum rotation speed of the motor in rotations per second
+        /// </summary>
+        public float maxSpeed = 5;
 
+        /// <summary>
+        /// The actual rotation speed in rotations per second
+        /// </summary>
+        public float rotationSpeed { get; protected set; }
+
+        /// <summary>
+        /// Update the Unity state
+        /// </summary>
+        protected override void FixedUpdate() {
+            base.FixedUpdate();
+            // We rotate the first child of the motor, which should be the axle.
+            float rotation = 360 * this.rotationSpeed * Time.fixedDeltaTime;
+            if (this.transform.childCount > 0)
+                this.transform.GetChild(0).Rotate(rotation, 0, 0);
+        }
+
+        /// <summary>
+        /// Handle the binary event containing the rotation speed
+        /// </summary>
         protected override void HandleBinary() {
             RoboidControl.Motor coreMotor = core as RoboidControl.Motor;
             this.rotationSpeed = coreMotor.targetSpeed * maxSpeed;
         }
 
-        protected override void Update() {
-            base.Update();
-            // We rotate the first child of the motor, which should be the axle.
-            float rotation = 360 * this.rotationSpeed * Time.deltaTime;
-            if (this.transform.childCount > 0)
-                this.transform.GetChild(0).Rotate(rotation, 0, 0);            
-        }
     }
 }
 #endif

Unity/Participant.cs

@@ -27,10 +27,12 @@ namespace RoboidControl.Unity {
         protected virtual void HandleThingEvent(RoboidControl.Participant.UpdateEvent e) {
             switch (e.thing) {
                 case RoboidControl.TouchSensor coreTouchSensor:
+                    Debug.Log("Handle TouchSensor");
                     TouchSensor touchSensor = TouchSensor.Create(coreTouchSensor);
                     coreTouchSensor.component = touchSensor;
                     break;
                 case RoboidControl.DifferentialDrive coreDrive:
+                    Debug.Log("Handle Diff.Drive");
                     DifferentialDrive differentialDrive = DifferentialDrive.Create(coreDrive);
                     coreDrive.component = differentialDrive;
                     break;
@@ -41,6 +43,7 @@ namespace RoboidControl.Unity {
                 //     // before we can create the wheel reliably
                 //     break;
                 case RoboidControl.Thing coreThing:
+                    Debug.Log("Handle Thing");
                     if (coreThing.component == null) {
                         Thing thing = Thing.Create(coreThing);
                         coreThing.component = thing;

Unity/RelativeEncoder.cs

@@ -0,0 +1,73 @@
+#if UNITY_5_3_OR_NEWER
+using System.Collections;
+using UnityEngine;
+using LinearAlgebra;
+
+namespace RoboidControl.Unity {
+    public class RelativeEncoder : Thing {
+
+        /// <summary>
+        /// Create the Unity representation
+        /// </summary>
+        /// <param name="core">The core motor</param>
+        /// <returns>The Unity representation of a motor</returns>
+        public static RelativeEncoder Create(RoboidControl.RelativeEncoder core) {
+            GameObject prefab = (GameObject)Resources.Load("IncrementalEncoder");
+            if (prefab != null) {
+                // Use resource prefab when available
+                GameObject gameObj = Instantiate(prefab);
+                RelativeEncoder component = gameObj.GetComponent<RelativeEncoder>();
+                if (component != null)
+                    component.core = core;
+                return component;
+            }
+            else {
+                // Fallback implementation
+                GameObject gameObj = new(core.name);
+                RelativeEncoder component = gameObj.AddComponent<RelativeEncoder>();
+                component.Init(core);
+
+                Rigidbody rb = gameObj.AddComponent<Rigidbody>();
+                rb.isKinematic = true;
+                return component;
+            }
+        }
+        RoboidControl.RelativeEncoder coreEncoder => this.core as RoboidControl.RelativeEncoder;
+
+        /// <summary>
+        /// The rotation speed in degrees per second
+        /// </summary>
+        public float rotationSpeed = 0.0f;
+
+        protected override void HandleBinary() {
+            this.rotationSpeed = coreEncoder.angularSpeed;
+        }
+
+        private Quaternion lastRotation;
+        protected override void Update() {
+            base.Update();
+            if (this.transform.childCount == 0)
+                return;
+
+            Transform child = this.transform.GetChild(0);
+
+            // Get the delta rotation since last frame
+            Quaternion deltaRotation = Quaternion.Inverse(lastRotation) * child.localRotation;
+
+            // Normalize angles to range [-180..180)
+            // Note: it is not possible to track rotation speeds higher than 180 degrees per frame because of representation limitations of Quaternions
+            float deltaAngle = Angle.Normalize(deltaRotation.eulerAngles.x);
+            this.rotationSpeed = deltaAngle / Time.deltaTime;
+        }
+
+        IEnumerator UpdateCore() {
+            WaitForSeconds wait = new(0.1f);
+
+            while (true) {
+                this.coreEncoder.angularSpeed = this.rotationSpeed;
+                yield return wait;
+            }
+        }
+    }
+}
+#endif

Unity/Thing.cs

@@ -2,39 +2,32 @@
 using System.Collections;
 using UnityEngine;
 using UnityEngine.Networking;
+#if GLTF
+using GLTFast;
+#endif
 
 namespace RoboidControl.Unity {
 
     /// <summary>
-    /// The representation of a Thing in Unity
+    /// The Unity representation fo a Roboid Control Thing
     /// </summary>
     public class Thing : MonoBehaviour {
 
         /// <summary>
         /// The core C# thing
         /// </summary>
-        //[field: SerializeField]
         public RoboidControl.Thing core { get; set; }
 
-        public SiteServer participant;
-
-        private string modelUrl = null;
+        /// <summary>
+        /// The owner of this thing
+        /// </summary>
+        public Participant owner;
 
         /// <summary>
-        /// Set the core C# thing
+        /// Create a Unity representation of a Thing
         /// </summary>
-        protected void SetCoreThing(RoboidControl.Thing thing) {
-            core = thing;
-            core.component = this;
-
-            SiteServer siteServer = FindAnyObjectByType<SiteServer>();
-            if (siteServer == null || siteServer.site == null) {
-                Debug.LogWarning("No site server found");
-                return;
-            }
-            siteServer.site.Add(thing);
-        }
-
+        /// <param name="core">The core of the thing</param>
+        /// <returns>The created thing</returns>
         public static Thing Create(RoboidControl.Thing core) {
             // Debug.Log("Creating new Unity thing");
             GameObject gameObj = string.IsNullOrEmpty(core.name) ?
@@ -45,11 +38,17 @@ namespace RoboidControl.Unity {
             return component;
         }
 
+        /// <summary>
+        /// Initialize the Thing
+        /// </summary>
+        /// <param name="core">The core of the thing</param>
+        /// This affects the parent and pose of the thing
         protected void Init(RoboidControl.Thing core) {
             this.core = core;
             this.core.component = this;
-            this.participant = FindAnyObjectByType<SiteServer>();
-            core.owner = this.participant.coreParticipant;
+            this.owner = FindAnyObjectByType<SiteServer>();
+            core.owner = this.owner.coreParticipant;
+
             if (core.parent != null && core.parent.component != null) {
                 this.transform.SetParent(core.parent.component.transform, false);
                 this.transform.localPosition = Vector3.zero;
@@ -62,7 +61,7 @@ namespace RoboidControl.Unity {
         }
 
         /// <summary>
-        /// Update the Unity representation
+        /// Update the Unity rendering
         /// </summary>
         protected virtual void Update() {
             if (core == null)
@@ -79,10 +78,16 @@ namespace RoboidControl.Unity {
             }
         }
 
+        /// <summary>
+        /// Update the Unity state (just calls UpdateThing)
+        /// </summary>
         protected virtual void FixedUpdate() {
             UpdateThing();
         }
 
+        /// <summary>
+        /// Update the Unity state
+        /// </summary>
         public void UpdateThing() {
             if (core == null) {
                 Debug.Log($"{this} core thing is gone, self destruct in 0 seconds...");
@@ -90,37 +95,50 @@ namespace RoboidControl.Unity {
                 return;
             }
 
-            if (core.updateQueue.TryDequeue(out RoboidControl.Thing.UpdateEvent e))
-                HandleUpdateEvent(e);
+            while (core.updateQueue.TryDequeue(out RoboidControl.Thing.CoreEvent e))
+                HandleCoreEvent(e);
         }
 
-        private void HandleUpdateEvent(RoboidControl.Thing.UpdateEvent e) {
-            switch (e.messageId) {
+        /// <summary>
+        /// Handle events from the core thing
+        /// </summary>
+        /// <param name="coreEvent">The core event to handle</param>
+        private void HandleCoreEvent(RoboidControl.Thing.CoreEvent coreEvent) {
+            switch (coreEvent.messageId) {
                 case ThingMsg.id:
+                    Debug.Log($"{this.core.id} Handle Thing");
                     if (core.parent == null)
                         this.transform.SetParent(null, true);
                     else if (core.parent.component != null)
                         this.transform.SetParent(core.parent.component.transform, true);
                     break;
                 case NameMsg.Id:
+                    Debug.Log($"{this.core.id} Handle Name");
                     this.gameObject.name = core.name;
                     break;
                 case ModelUrlMsg.Id:
+                    Debug.Log("{this.id} Handle Model URL");
                     string extension = core.modelUrl[core.modelUrl.LastIndexOf(".")..];
                     if (extension == ".jpg" || extension == ".png")
                         StartCoroutine(LoadJPG());
-
-                    this.modelUrl = core.modelUrl;
+                    else if (extension == ".gltf" || extension == ".glb")
+                        ProcessGltfModel(core);
                     break;
                 case PoseMsg.Id:
+                    Debug.Log($"{this.core.id} Handle Pose");
                     this.HandlePose();
                     break;
                 case BinaryMsg.Id:
+                    Debug.Log($"{this.core.id} Handle Binary");
                     this.HandleBinary();
                     break;
             }
         }
 
+        /// <summary>
+        /// Load and attach a JPG sprite visualization of the thing
+        /// </summary>
+        /// <returns></returns>
         private IEnumerator LoadJPG() {
             UnityWebRequest request = UnityWebRequestTexture.GetTexture(core.modelUrl);
             yield return request.SendWebRequest();
@@ -148,6 +166,93 @@ namespace RoboidControl.Unity {
             }
         }
 
+        bool loadingModel = false;
+        private async void ProcessGltfModel(RoboidControl.Thing coreThing) {
+#if GLTF            
+            if (!loadingModel) {
+                loadingModel = true;
+
+                Debug.Log("Loading GLTF model from :" + coreThing.modelUrl);
+                GltfImport gltfImport = new GltfImport();
+                bool success = await gltfImport.Load(coreThing.modelUrl);
+                if (success) {
+                    Transform parentTransform = this.transform;
+
+                    Thing[] things = FindObjectsOfType<Thing>();
+                    Thing parentThing = null;
+                    foreach (Thing thing in things) {
+                        if (thing.core.id == coreThing.id) {
+                            parentTransform = thing.transform;
+                            parentThing = thing;
+                        }
+                    }
+                    await gltfImport.InstantiateMainSceneAsync(parentTransform);
+                    SkinnedMeshRenderer[] meshRenderers = parentTransform.GetComponentsInChildren<SkinnedMeshRenderer>();
+
+#if pHUMANOID4
+                if (parentThing.objectType == 7) {
+                    HumanoidControl hc = parentThing.gameObject.GetComponent<HumanoidControl>();
+                    if (hc == null)
+                        hc = parentThing.gameObject.AddComponent<HumanoidControl>();
+
+                    foreach (SkinnedMeshRenderer meshRenderer in meshRenderers) {
+                        if (meshRenderer.rootBone != null) {
+                            Debug.Log("Found a skinned mesh with bones");
+                            hc.RetrieveBonesFrom(meshRenderer.rootBone);
+                            break;
+                        }
+                    }
+                }
+#endif
+                    parentTransform.localScale = Vector3.one;
+                    if (meshRenderers.Length > 0) {
+                        foreach (SkinnedMeshRenderer meshRenderer in meshRenderers) {
+                            if (meshRenderer.rootBone != null) {
+                                Debug.Log("Found a skinned mesh with bones");
+                                ScanForThings(meshRenderer.rootBone);
+                                break;
+                            }
+                        }
+                    }
+                    else {
+                        ScanForThings(parentTransform);
+                    }
+                }
+                else {
+                    this.transform.localScale = Vector3.one * 1;
+                }
+            }
+            loadingModel = true;
+#endif            
+        }
+
+        private void ScanForThings(Transform rootTransform) {
+            // Thing[] thingArray = allThings.ToArray();
+
+            // for (int thingIx = 0; thingIx < thingArray.Length; thingIx++) {
+            //     Thing thing = thingArray[thingIx];
+            //     GameObject foundObj = FindThingByName(thing, rootTransform);
+            //     if (foundObj != null && foundObj != thing.gameObject) {
+            //         Thing foundThing = foundObj.GetComponent<Thing>();
+            //         if (foundThing == null) {
+            //             allThings.Remove(thing);
+
+            //             foundThing = foundObj.AddComponent<Thing>();
+            //             foundThing.networkId = thing.networkId;
+            //             foundThing.objectId = thing.objectId;
+            //             allThings.Add(foundThing);
+            //             Destroy(thing.gameObject);
+            //         }
+            //     }
+            // }
+        }
+
+
+        /// <summary>
+        /// Handle a Pose event
+        /// </summary>
+        /// This can update the position and/or orientation when the velocity of the thing is zero.
+        /// If a velocity is not zero, the position and/or orientation update will be ignored
         protected virtual void HandlePose() {
             if (core.linearVelocity.distance == 0)
                 this.transform.localPosition = core.position.ToVector3();
@@ -155,6 +260,10 @@ namespace RoboidControl.Unity {
                 this.transform.localRotation = core.orientation.ToQuaternion();
 
         }
+
+        /// <summary>
+        /// Handle a Binary event
+        /// </summary>
         protected virtual void HandleBinary() { }
 
     }

Unity/TouchSensor.cs

@@ -4,52 +4,36 @@ using UnityEngine;
 namespace RoboidControl.Unity {
 
 	/// <summary>
-	/// The Unity representation of the TouchSensor
+	/// The Unity representation of a Roboid Control touch sensor
 	/// </summary>
 	public class TouchSensor : Thing {
 
-		// public SiteServer participant;
 		/// <summary>
 		/// The core touch sensor
 		/// </summary>
-		public RoboidControl.TouchSensor coreSensor {
-			get => base.core as RoboidControl.TouchSensor;
-			set => base.core = value;
-		}
-
-		SphereCollider touchCollider = null;
+		public RoboidControl.TouchSensor coreSensor => base.core as RoboidControl.TouchSensor;
 
 		/// <summary>
-		/// Start the Unity represention
+		/// Create the Unity representation of the touch sensor
 		/// </summary>
-		protected virtual void Start() {
-			if (core == null) {
-				participant = FindAnyObjectByType<SiteServer>();
-				SetCoreThing(new RoboidControl.TouchSensor(participant.site));
-			}
-			touchCollider = GetComponent<SphereCollider>();
-		}
-
-		/// <summary>
-		/// Create the Unity representation
-		/// </summary>
-		/// <param name="core">The core touch sensor</param>
+		/// <param name="coreSensor">The core touch sensor</param>
 		/// <returns>The Unity representation of the touch sensor</returns>
-		public static TouchSensor Create(RoboidControl.TouchSensor core) {
+		/// This uses a 'TouchSensor' resource when available for the Unity representation.
+		/// If this is not available, a default representation is created.
+		public static TouchSensor Create(RoboidControl.TouchSensor coreSensor) {
+			TouchSensor touchSensor;
 			GameObject prefab = (GameObject)Resources.Load("TouchSensor");
 			if (prefab != null) {
 				// Use resource prefab when available
 				GameObject gameObj = Instantiate(prefab);
-				TouchSensor component = gameObj.GetComponent<TouchSensor>();
-				if (component != null)
-					component.core = core;
-				return component;
+				touchSensor = gameObj.GetComponent<TouchSensor>();
+				touchSensor.Init(coreSensor);
 			}
 			else {
-				// Fallback implementation
-				GameObject gameObj = new(core.name);
-				TouchSensor component = gameObj.AddComponent<TouchSensor>();
-				component.Init(core);
+				// Default implementation
+				GameObject gameObj = new(coreSensor.name);
+				touchSensor = gameObj.AddComponent<TouchSensor>();
+				touchSensor.Init(coreSensor);
 
 				Rigidbody rb = gameObj.AddComponent<Rigidbody>();
 				rb.isKinematic = true;
@@ -57,30 +41,33 @@ namespace RoboidControl.Unity {
 				SphereCollider collider = gameObj.AddComponent<SphereCollider>();
 				collider.radius = 0.01f;
 				collider.isTrigger = true;
-				return component;
 			}
+			return touchSensor;
 		}
 
+		/// <summary>
+		/// Handle touch trigger collider enter event
+		/// </summary>
+		/// <param name="other">The collider which entered our trigger collider</param>
 		private void OnTriggerEnter(Collider other) {
-			// Debug.Log("Touch?");
-			if (other.isTrigger) {
-				// Debug.Log($"   was trigger {other.name}");
+			// Don't detect trigger colliders
+			if (other.isTrigger)
 				return;			
-			}
-			if (this.transform.root == other.transform.root) {
-				Debug.Log($"   was myself {other.name}");
+			// Don't touch yourself
+			if (this.transform.root == other.transform.root)
 				return;			
-			}
 
-			Debug.Log($"*** {this} Touch");
 			this.coreSensor.touchedSomething = true;
-			this.core.updateQueue.Enqueue(new RoboidControl.Thing.UpdateEvent(BinaryMsg.Id));
+			this.core.updateQueue.Enqueue(new RoboidControl.Thing.CoreEvent(BinaryMsg.Id));
 		}
+		/// <summary>
+		/// Handl touch trigger collider exit event
+		/// </summary>
+		/// <param name="other">The collider which exited our trigger collider </param>
 		private void OnTriggerExit(Collider other) {
 			if (other.isTrigger)
 				return;
 
-			Debug.Log($"*** {this} Touch end");
 			this.coreSensor.touchedSomething = false;
 		}
 	}

Unity/Wheel.cs

@@ -2,6 +2,10 @@
 using UnityEngine;
 
 namespace RoboidControl.Unity {
+
+    /// <summary>
+    /// The Unity representation of a Roboid Control wheel
+    /// </summary>
     public class Wheel : Motor {
         /// <summary>
         /// Create the Unity representation
@@ -23,14 +27,6 @@ namespace RoboidControl.Unity {
                 GameObject gameObj = new(core.name);
                 Wheel component = gameObj.AddComponent<Wheel>();
                 component.Init(core);
-                // component.wheelCollider = gameObj.AddComponent<WheelCollider>();
-                // component.wheelCollider.mass = 0.1f;
-                // component.wheelCollider.suspensionDistance = 0.01f;
-                // component.wheelCollider.suspensionSpring = new JointSpring {
-                //     spring = 100f, // Very high spring value to make it rigid
-                //     damper = 10f,    // Low damping (could be adjusted for slight 'bounciness')
-                //     targetPosition = 0.5f // Neutral position (middle of the suspension travel)
-                // };
                 Debug.Log("Create " + core.name);
                 return component;
             }
@@ -61,14 +57,6 @@ namespace RoboidControl.Unity {
                 SphereCollider collider = gameObj.AddComponent<SphereCollider>();
                 collider.radius = 0.00001f;
                 collider.material = slidingWheel;
-                // component.wheelCollider = gameObj.AddComponent<WheelCollider>();
-                // component.wheelCollider.mass = 0.1f;
-                // component.wheelCollider.suspensionDistance = 0.01f;
-                // component.wheelCollider.suspensionSpring = new JointSpring {
-                //     spring = 100f, // Very high spring value to make it rigid
-                //     damper = 10f,    // Low damping (could be adjusted for slight 'bounciness')
-                //     targetPosition = 0.5f // Neutral position (middle of the suspension travel)
-                // };
                 Debug.Log("Create placeholder Wheel ");
                 return component;
             }

src/Thing.cs

@@ -26,6 +26,7 @@ namespace RoboidControl {
             public const byte ControlledMotor = 0x06;
             public const byte UncontrolledMotor = 0x07;
             public const byte Servo = 0x08;
+            public const byte IncrementalEncoder = 0x19;
             // Other
             public const byte Roboid = 0x09;
             public const byte HUmanoid = 0x0A;
@@ -137,7 +138,7 @@ namespace RoboidControl {
                 if (_name != value) {
                     _name = value;
                     nameChanged = true;
-                    this.updateQueue.Enqueue(new UpdateEvent(NameMsg.Id));
+                    this.updateQueue.Enqueue(new CoreEvent(NameMsg.Id));
                 }
             }
         }
@@ -152,7 +153,7 @@ namespace RoboidControl {
             set {
                 if (_modelUrl != value) {
                     _modelUrl = value;
-                    this.updateQueue.Enqueue(new UpdateEvent(ModelUrlMsg.Id));
+                    this.updateQueue.Enqueue(new CoreEvent(ModelUrlMsg.Id));
                 }
             }
         }
@@ -187,7 +188,7 @@ namespace RoboidControl {
                     value.AddChild(this);
                 }
                 this.hierarchyChanged = true;
-                this.updateQueue.Enqueue(new UpdateEvent(ThingMsg.id));
+                this.updateQueue.Enqueue(new CoreEvent(ThingMsg.id));
             }
         }
 
@@ -282,7 +283,7 @@ namespace RoboidControl {
                 if (_position != value) {
                     _position = value;
                     positionUpdated = true;
-                    updateQueue.Enqueue(new UpdateEvent(PoseMsg.Id));
+                    updateQueue.Enqueue(new CoreEvent(PoseMsg.Id));
                 }
             }
         }
@@ -320,7 +321,7 @@ namespace RoboidControl {
                 if (_linearVelocity != value) {
                     _linearVelocity = value;
                     linearVelocityUpdated = true;
-                    updateQueue.Enqueue(new UpdateEvent(PoseMsg.Id));
+                    updateQueue.Enqueue(new CoreEvent(PoseMsg.Id));
                 }
             }
         }
@@ -339,7 +340,7 @@ namespace RoboidControl {
                 if (_angularVelocity != value) {
                     _angularVelocity = value;
                     angularVelocityUpdated = true;
-                    updateQueue.Enqueue(new UpdateEvent(PoseMsg.Id));
+                    updateQueue.Enqueue(new CoreEvent(PoseMsg.Id));
                 }
             }
         }
@@ -395,13 +396,13 @@ namespace RoboidControl {
             }
         }
 
-        public class UpdateEvent {
-            public UpdateEvent(int messageId) {
+        public class CoreEvent {
+            public CoreEvent(int messageId) {
                 this.messageId = messageId;
             }
             public int messageId; // see the communication messages
         };
-        public ConcurrentQueue<UpdateEvent> updateQueue = new();
+        public ConcurrentQueue<CoreEvent> updateQueue = new();
 
         #endregion Update
 

src/Things/DifferentialDrive.cs

@@ -18,16 +18,16 @@ namespace RoboidControl {
         /// <param name="thingId">The ID of the thing, leave out or set to zero to generate an ID</param>
         /// <param name="invokeEvent">Invoke a OnNewThing event when the thing has been created</param>
         public DifferentialDrive(Participant owner, byte thingId = 0, bool invokeEvent = true) : base(owner, Type.DifferentialDrive, thingId, invokeEvent) {
-            Motor leftWheel = new(this) {
-                name = "Left Wheel"
-            };
-            Motor rightWheel = new(this) {
-                name = "Right Wheel"
-            };
-            SetMotors(leftWheel, rightWheel);
-            sendBinary = true;
-            owner.Send(new BinaryMsg(owner.networkId, this));
-            this.updateQueue.Enqueue(new UpdateEvent(BinaryMsg.Id));
+            // Motor leftWheel = new(this) {
+            //     name = "Left Wheel"
+            // };
+            // Motor rightWheel = new(this) {
+            //     name = "Right Wheel"
+            // };
+            // SetMotors(leftWheel, rightWheel);
+            // sendBinary = true;
+            // owner.Send(new BinaryMsg(owner.networkId, this));
+            // this.updateQueue.Enqueue(new UpdateEvent(BinaryMsg.Id));
 
         }
         /// <summary>
@@ -45,31 +45,38 @@ namespace RoboidControl {
         /// These values are used to compute the desired wheel speed from the set
         /// linear and angular velocity.
         /// @sa SetLinearVelocity SetAngularVelocity
-        public void SetDriveDimensions(float wheelDiameter, float wheelSeparation) {
+        public void SetDriveDimensions(float wheelDiameter, float wheelSeparation = 0) {
             this._wheelRadius = wheelDiameter > 0 ? wheelDiameter / 2 : -wheelDiameter / 2;
-            this._wheelSeparation = wheelSeparation > 0 ? wheelSeparation : -wheelSeparation;
             this.rpsToMs = wheelDiameter * Angle.pi;
 
-            float distance = this.wheelSeparation / 2;
-            if (this.leftWheel != null)
-                this.leftWheel.position = new Spherical(distance, Direction.left);
-            if (this.rightWheel != null)
-                this.rightWheel.position = new Spherical(distance, Direction.right);
+            if (wheelSeparation > 0) {
+                wheelSeparation = wheelSeparation > 0 ? wheelSeparation : -wheelSeparation;
+                float distance = wheelSeparation / 2;
+                if (this.leftWheel != null)
+                    this.leftWheel.position = new Spherical(distance, Direction.left);
+                if (this.rightWheel != null)
+                    this.rightWheel.position = new Spherical(distance, Direction.right);
+            }
         }
 
         /// @brief Congures the motors for the wheels
         /// @param leftWheel The motor for the left wheel
         /// @param rightWheel The motor for the right wheel
         public void SetMotors(Motor leftWheel, Motor rightWheel) {
-            float distance = this.wheelSeparation / 2;
+            // float distance = this.wheelSeparation / 2;
 
             this.leftWheel = leftWheel;
-            if (this.leftWheel != null)
-                this.leftWheel.position = new Spherical(distance, Direction.left);
+            this.leftWheel.parent = this;
+            // if (this.leftWheel != null)
+            //     this.leftWheel.position = new Spherical(distance, Direction.left);
 
             this.rightWheel = rightWheel;
-            if (this.rightWheel != null)
-                this.rightWheel.position = new Spherical(distance, Direction.right);
+            this.rightWheel.parent= this;
+            // if (this.rightWheel != null)
+            //     this.rightWheel.position = new Spherical(distance, Direction.right);
+
+            owner.Send(new BinaryMsg(owner.networkId, this));
+            this.updateQueue.Enqueue(new CoreEvent(BinaryMsg.Id));
         }
 
         /// @brief Directly specify the speeds of the motors
@@ -87,6 +94,18 @@ namespace RoboidControl {
                 //this.rightWheel.angularVelocity = new Spherical(speedRight, Direction.right);
             }
         }
+        /// @brief Directly specify the speeds of the motors
+        /// @param speedLeft The speed of the left wheel in degrees per second.
+        /// Positive moves the robot in the forward direction.
+        /// @param speedRight The speed of the right wheel in degrees per second.
+        /// Positive moves the robot in the forward direction.
+        public void SetWheelAngularVelocity(float angularSpeedLeft, float angularSpeedRight) {
+            // This only works when the motor is a motor with encoder
+            if (this.leftWheel is EncoderMotor leftMotor)
+                leftMotor.targetAngularSpeed = angularSpeedLeft;
+            if (this.rightWheel is EncoderMotor rightMotor)
+                rightMotor.targetAngularSpeed = angularSpeedRight;
+        }
 
         /// @copydoc RoboidControl::Thing::Update(unsigned long)
         public override void Update(ulong currentMs, bool recursive = true) {
@@ -100,9 +119,10 @@ namespace RoboidControl {
                 if (angularVelocity.direction.horizontal < 0)
                     angularSpeed = -angularSpeed;
 
-                // wheel separation can be replaced by this.leftwheel.position.distance
-                float speedLeft = (linearVelocity + angularSpeed * this.wheelSeparation / 2) / this.wheelRadius * Angle.Rad2Deg;
-                float speedRight = (linearVelocity - angularSpeed * this.wheelSeparation / 2) / this.wheelRadius * Angle.Rad2Deg;
+                // This assumes that the left wheel position has Direction.left
+                // and the right wheel position has Direction.Right...
+                float speedLeft = (linearVelocity + angularSpeed * this.leftWheel.position.distance) / this.wheelRadius * Angle.Rad2Deg;
+                float speedRight = (linearVelocity - angularSpeed * this.rightWheel.position.distance) / this.wheelRadius * Angle.Rad2Deg;
                 this.SetWheelVelocity(speedLeft, speedRight);
             }
         }
@@ -111,8 +131,8 @@ namespace RoboidControl {
         private float _wheelRadius = 0.0f;
         public float wheelRadius { get => _wheelRadius; }
         /// @brief The distance between the wheels in meters
-        private float _wheelSeparation = 0.0f;
-        public float wheelSeparation { get => _wheelSeparation; }
+        // private float _wheelSeparation = 0.0f;
+        // public float wheelSeparation { get => _wheelSeparation; }
 
         /// @brief Convert revolutions per second to meters per second
         protected float rpsToMs = 1.0f;
@@ -127,12 +147,12 @@ namespace RoboidControl {
             if (!sendBinary)
                 return System.Array.Empty<byte>();
 
-            byte[] data = new byte[6];
+            byte[] data = new byte[4];
             byte ix = 0;
             data[ix++] = leftWheel.id;
             data[ix++] = rightWheel.id;
             LowLevelMessages.SendFloat16(data, ref ix, wheelRadius);
-            LowLevelMessages.SendFloat16(data, ref ix, wheelSeparation);
+            //LowLevelMessages.SendFloat16(data, ref ix, wheelSeparation);
             sendBinary = false;
             return data;
         }
@@ -144,8 +164,8 @@ namespace RoboidControl {
             byte rightWheelId = data[ix++];
             this.rightWheel = this.owner.Get(rightWheelId) as Motor;
             this._wheelRadius = LowLevelMessages.ReceiveFloat16(data, ref ix);
-            this._wheelSeparation = LowLevelMessages.ReceiveFloat16(data, ref ix);
-            this.updateQueue.Enqueue(new UpdateEvent(BinaryMsg.Id));
+            //this._wheelSeparation = LowLevelMessages.ReceiveFloat16(data, ref ix);
+            this.updateQueue.Enqueue(new CoreEvent(BinaryMsg.Id));
         }
     };
 

src/Things/EncoderMotor.cs

@@ -0,0 +1,84 @@
+namespace RoboidControl {
+
+    /// @brief A motor with speed control
+    /// It uses a feedback loop from an encoder to regulate the speed
+    /// The speed is measured in revolutions per second.
+    class EncoderMotor : Motor {
+        public EncoderMotor(Thing parent, RelativeEncoder encoder) : base(parent) {
+            this.encoder = encoder;
+         }
+        // Upgrade an existing motor with an encoder
+        public EncoderMotor(Motor motor, RelativeEncoder encoder) : base(motor.parent) {
+            this.motor = motor;
+            this.encoder = encoder;
+         }
+
+        readonly RelativeEncoder encoder;
+        readonly Motor motor;
+
+        public override float targetSpeed {
+            get {
+                if (this.motor != null)
+                    return this.motor.targetSpeed;
+                else
+                    return base.targetSpeed;
+            }
+            set {
+                if (this.motor != null)
+                    this.motor.targetSpeed = value;
+                else
+                    base.targetSpeed = value;
+            }
+        }
+
+        private float _targetAngularSpeed; // In degrees per second
+        public virtual float targetAngularSpeed {
+            get => _targetAngularSpeed;
+            set {
+                if (value != this._targetAngularSpeed) {
+                    this._targetAngularSpeed = value;
+                    updateQueue.Enqueue(new CoreEvent(BinaryMsg.Id));
+                    owner.Send(new BinaryMsg(this));
+                }
+            }
+        }
+        /// @brief Get the actual speed from the encoder
+        /// @return The speed in angle per second
+        public virtual float actualAngularSpee {
+            get => encoder.angularSpeed;
+        }
+
+        float pidP = 0.1F;
+        float pidD = 0.0F;
+        float pidI = 0.0F;
+
+        public override void Update(ulong currentTimeMs, bool recurse = false) {
+            float actualSpeed = this.encoder.angularSpeed;
+            // Simplified rotation direction, shouldbe improved
+            // This goes wrong when the target speed is inverted and the motor axcle is still turning in the old direction
+            if (this.targetAngularSpeed < 0)
+                actualSpeed = -actualSpeed;
+
+            float deltaTime = (currentTimeMs - this.lastUpdateTime) / 1000.0f;
+
+            float error = this.targetAngularSpeed - actualSpeed;
+            float errorChange = (error - lastError) * deltaTime;
+
+            float delta = error * pidP + errorChange * pidD;
+
+            // Update the motor speed
+            if (motor != null)
+                motor.targetSpeed += delta;
+            else
+                base.targetSpeed += delta;
+            this.lastUpdateTime = currentTimeMs;
+        }
+
+        ulong lastUpdateTime = 0;
+        float lastError = 0;
+
+        // enum Direction { Forward = 1, Reverse = -1 };
+        // Direction rotationDirection;
+    };
+
+} // namespace RoboidControl

src/Things/Motor.cs

@@ -16,16 +16,16 @@ namespace RoboidControl {
 
         protected float currentTargetSpeed = 0;
 
-        private float _targetSpeed;
+        private float _targetSpeed = 0;
         /// <summary>
         /// The speed between -1 (full reverse), 0 (stop) and 1 (full forward)
         /// </summary>
-        public float targetSpeed {
+        public virtual float targetSpeed {
             get => _targetSpeed;
             set {
                 if (value != _targetSpeed) {
                     _targetSpeed = Float.Clamp(value, -1, 1);
-                    updateQueue.Enqueue(new UpdateEvent(BinaryMsg.Id));
+                    updateQueue.Enqueue(new CoreEvent(BinaryMsg.Id));
                     owner.Send(new BinaryMsg(this));
                 }
             }

src/Things/RelativeEncoder.cs

@@ -0,0 +1,40 @@
+
+namespace RoboidControl {
+
+    /// @brief An Incremental Encoder measures the rotations of an axle using a rotary
+    /// sensor. Some encoders are able to detect direction, while others can not.
+    public class RelativeEncoder : Thing {
+        /// @brief Creates a sensor which measures distance from pulses
+        /// @param pulsesPerRevolution The number of pulse edges which make a
+        /// full rotation
+        /// @param distancePerRevolution The distance a wheel travels per full
+        /// rotation
+        public RelativeEncoder(bool invokeEvent = true) : base(Type.IncrementalEncoder, invokeEvent) { }
+
+        protected float _rotationSpeed = 0;
+        /// @brief Get the rotation speed since the previous call
+        /// @param currentTimeMs The clock time in milliseconds
+        /// @return The speed in rotations per second        
+        public virtual float angularSpeed {
+            get => _rotationSpeed;
+            set {
+                if (_rotationSpeed != value) {
+                    _rotationSpeed = value;
+                    this.owner.Send(new BinaryMsg(this));
+                }
+            }
+        }
+
+        public override byte[] GenerateBinary() {
+            byte[] data = new byte[1];
+            byte ix = 0;
+            data[ix++] = (byte)(this._rotationSpeed * 127);
+            return data;
+        }
+        public override void ProcessBinary(byte[] data) {
+            this._rotationSpeed = (float)data[0] / 127;
+        }
+
+    };
+
+} // namespace RoboidControl