First step to adding differential dirve

Examples/BB2B/BB2B.cs

@@ -1,39 +1,40 @@
 
 namespace RoboidControl {
 
-public class BB2B : Thing {
+    // The robot is based on a differential drive
-    readonly DifferentialDrive drive;
+    public class BB2B : DifferentialDrive {
-    readonly TouchSensor touchLeft;
+        readonly DifferentialDrive drive;
-    readonly TouchSensor touchRight;
+        readonly TouchSensor touchLeft;
+        readonly TouchSensor touchRight;
 
-    public BB2B() : base(128) { // thingType = 128
+        public BB2B(Participant owner) : base(owner) {
+            this.name = "BB2B";
+            this.wheelRadius = 0.032f;
+            this.wheelSeparation = 0.128f;
 
-        // The robot's propulsion is a differential drive
+            // Is has a touch sensor at the front left of the roboid
-        drive = new();
+            touchLeft = new(this);
+            // and other one on the right
+            touchRight = new(this);
+        }
 
-        // Is has a touch sensor at the front left of the roboid
+        public override void Update(ulong currentTimeMs, bool recurse = true) {
-        touchLeft = new(drive);
+
-        // and other one on the right
+            // The left wheel turns forward when nothing is touched on the right side
-        touchRight = new(drive);
+            // and turn backward when the roboid hits something on the right
+            float leftWheelSpeed = touchRight.touchedSomething ? -600.0f : 600.0f;
+
+            // The right wheel does the same, but instead is controlled by
+            // touches on the left side
+            float rightWheelSpeed = touchLeft.touchedSomething ? -600.0f : 600.0f;
+
+            // When both sides are touching something, both wheels will turn backward
+            // and the roboid will move backwards
+
+            this.SetWheelVelocity(leftWheelSpeed, rightWheelSpeed);
+
+            base.Update(currentTimeMs, recurse);
+        }
     }
 
-    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 leftWheelSpeed = touchRight.touchedSomething ? -600.0f : 600.0f;
-
-        // The right wheel does the same, but instead is controlled by
-        // touches on the left side
-        float rightWheelSpeed = touchLeft.touchedSomething ? -600.0f : 600.0f;
-
-        // When both sides are touching something, both wheels will turn backward
-        // and the roboid will move backwards
-
-        drive.SetWheelVelocity(leftWheelSpeed, rightWheelSpeed);
-
-        base.Update(currentTimeMs, recurse);
-    }
 }
-
-}

Examples/BB2B/Program.cs

@@ -3,7 +3,7 @@ using RoboidControl;
 
 class Program {
     static void Main() {
-        BB2B bb2b = new();
+        BB2B bb2b = new(ParticipantUDP.Isolated());
 
         while (true) {
             bb2b.Update();

Unity/DifferentialDrive.cs

@@ -0,0 +1,108 @@
+#if UNITY_5_3_OR_NEWER
+using System.Linq;
+using UnityEngine;
+
+namespace RoboidControl.Unity {
+    public class DifferentialDrive : Thing {
+
+        public WheelCollider leftWheel;
+        public WheelCollider rightWheel;
+
+        /// <summary>
+        /// Create the Unity representation
+        /// </summary>
+        /// <param name="core">The core touch sensor</param>
+        /// <returns>The Unity representation of the touch sensor</returns>
+        public static DifferentialDrive Create(RoboidControl.DifferentialDrive core) {
+            GameObject gameObj = new(core.name);
+            DifferentialDrive component = gameObj.AddComponent<DifferentialDrive>();
+            component.Init(core);
+
+            Rigidbody rb = gameObj.AddComponent<Rigidbody>();
+            rb.isKinematic = false;
+            rb.mass = 0.5f;
+
+            return component;
+        }
+
+        protected override void HandleBinary() {
+            RoboidControl.DifferentialDrive drive = core as RoboidControl.DifferentialDrive;
+            if (leftWheel == null) {
+                GameObject leftWheelObj = new GameObject("Left wheel");
+                leftWheelObj.transform.SetParent(this.transform);
+                leftWheel = leftWheelObj.AddComponent<WheelCollider>();
+                leftWheel.mass = 0.1f;
+                leftWheel.suspensionDistance = 0.01f;
+                leftWheel.suspensionSpring = new JointSpring {
+                    spring = 1000f, // Very high spring value to make it rigid
+                    damper = 100f,    // Low damping (could be adjusted for slight 'bounciness')
+                    targetPosition = 0.5f // Neutral position (middle of the suspension travel)
+                };
+                leftWheel.radius = drive.wheelRadius;
+                leftWheel.center = new Vector3(-drive.wheelSeparation / 2, 0, 0);
+            }
+            if (rightWheel == null) {
+                GameObject rightWheelObj = new GameObject("Left wheel");
+                rightWheelObj.transform.SetParent(this.transform);
+                rightWheel = rightWheelObj.AddComponent<WheelCollider>();
+                rightWheel.mass = 0.1f;
+                rightWheel.suspensionDistance = 0.01f;
+                rightWheel.suspensionSpring = new JointSpring {
+                    spring = 1000f, // Very high spring value to make it rigid
+                    damper = 100f,    // Low damping (could be adjusted for slight 'bounciness')
+                    targetPosition = 0.5f // Neutral position (middle of the suspension travel)
+                };
+                rightWheel.radius = drive.wheelRadius;
+                rightWheel.center = new Vector3(drive.wheelSeparation / 2, 0, 0);
+
+            }
+            // Thing[] children = this.GetComponentsInChildren<Thing>();
+            // if (leftWheel == null) {
+            //     leftWheel = children.FirstOrDefault(child => child.core.id == drive.leftWheel.id);
+            //     if (leftWheel == null) {
+            //         RoboidControl.Thing coreThing = new(drive.owner, 0, drive.leftWheel.id, false) {
+            //             name = "Left Wheel"
+            //         };
+            //         leftWheel = Thing.Create(coreThing);
+            //         leftWheel.transform.SetParent(this.transform);
+            //     }
+            //     WheelCollider wheel = this.GetComponent<WheelCollider>();
+            //     if (wheel == null)
+            //         wheel = this.gameObject.AddComponent<WheelCollider>();
+            //     wheel.mass = 0.1f;
+            //     wheel.suspensionDistance = 0.01f;
+            //     wheel.suspensionSpring = new JointSpring {
+            //         spring = 1000f, // Very high spring value to make it rigid
+            //         damper = 100f,    // Low damping (could be adjusted for slight 'bounciness')
+            //         targetPosition = 0.5f // Neutral position (middle of the suspension travel)
+            //     };
+            //     wheel.radius = drive.wheelRadius;
+            //     wheel.center = new Vector3(-drive.wheelSeparation / 2, 0, 0);
+            // }
+            // if (rightWheel == null) {
+            //     this.rightWheel = children.FirstOrDefault(child => child.core.id == drive.rightWheel.id);
+            //     if (this.rightWheel == null) {
+            //         RoboidControl.Thing coreThing = new(drive.owner, 0, drive.rightWheel.id, false) {
+            //             name = "Right Wheel"
+            //         };
+            //         this.rightWheel = Thing.Create(coreThing);
+            //         this.rightWheel.transform.SetParent(this.transform);
+            //     }
+            //     WheelCollider wheel = this.GetComponent<WheelCollider>();
+            //     if (wheel == null)
+            //         wheel = this.gameObject.AddComponent<WheelCollider>();
+            //     wheel.mass = 0.1f;
+            //     wheel.suspensionDistance = 0.01f;
+            //     wheel.suspensionSpring = new JointSpring {
+            //         spring = 1000f, // Very high spring value to make it rigid
+            //         damper = 100f,    // Low damping (could be adjusted for slight 'bounciness')
+            //         targetPosition = 0.5f // Neutral position (middle of the suspension travel)
+            //     };
+            //     wheel.radius = drive.wheelRadius;
+            //     wheel.center = new Vector3(drive.wheelSeparation / 2, 0, 0);
+            // }
+        }
+    }
+
+}
+#endif

Unity/Participant.cs

@@ -24,15 +24,21 @@ namespace RoboidControl.Unity {
             }
         }
 
-        private void HandleThingEvent(RoboidControl.Participant.UpdateEvent e) {
+        protected virtual void HandleThingEvent(RoboidControl.Participant.UpdateEvent e) {
             switch (e.thing) {
                 case RoboidControl.TouchSensor coreTouchSensor:
                     TouchSensor touchSensor = TouchSensor.Create(coreTouchSensor);
                     coreTouchSensor.component = touchSensor;
                     break;
+                case RoboidControl.DifferentialDrive coreDrive:
+                    DifferentialDrive differentialDrive = DifferentialDrive.Create(coreDrive);
+                    coreDrive.component = differentialDrive;
+                    break;
                 case RoboidControl.Thing coreThing:
-                    Thing thing = Thing.Create(coreThing);
+                    if (coreThing.component != null) {
-                    coreThing.component = thing;
+                        Thing thing = Thing.Create(coreThing);
+                        coreThing.component = thing;
+                    }
                     break;
             }
         }

Unity/SiteServer.cs

@@ -42,7 +42,8 @@ namespace RoboidControl.Unity {
                     participant.coreParticipant = e.participant;
                     break;
                 case ThingMsg.id:
-                    e.thing.CreateComponent();
+                    HandleThingEvent(e);
+                    //e.thing.CreateComponent();
                     break;
             }
         }

Unity/Thing.cs

@@ -48,6 +48,7 @@ namespace RoboidControl.Unity {
         protected void Init(RoboidControl.Thing core) {
             this.core = core;
             this.participant = FindAnyObjectByType<SiteServer>();
+            core.owner = this.participant.coreParticipant;
             if (core.parent != null && core.parent.component != null)
                 this.transform.SetParent(core.parent.component.transform, false);
 
@@ -105,6 +106,9 @@ namespace RoboidControl.Unity {
                     if (core.angularVelocity.distance == 0)
                         this.transform.localRotation = core.orientation.ToQuaternion();
                     break;
+                case BinaryMsg.Id:
+                    this.HandleBinary();
+                    break;
             }
         }
 
@@ -143,6 +147,7 @@ namespace RoboidControl.Unity {
             }
         }
 
+        protected virtual void HandleBinary() {}
 
     }
 

Unity/TouchSensor.cs

@@ -36,9 +36,7 @@ namespace RoboidControl.Unity {
 		/// <param name="core">The core touch sensor</param>
 		/// <returns>The Unity representation of the touch sensor</returns>
 		public static TouchSensor Create(RoboidControl.TouchSensor core) {
-			GameObject gameObj = core.name != null ?
+			GameObject gameObj = new(core.name);
-				new(core.name) :
-				new("Touch Sensor");
 			TouchSensor component = gameObj.AddComponent<TouchSensor>();
 			component.Init(core);
 

src/Participants/SiteServer.cs

@@ -117,16 +117,7 @@ namespace RoboidControl {
             Console.WriteLine($"{this.name}: Process thing [{msg.networkId}/{msg.thingId}] {msg.thingType} {msg.parentId} ");
 
             Thing thing = sender.Get(msg.thingId);
-            if (thing == null) {
+            thing ??= ProcessNewThing(sender, msg);
-                switch (msg.thingType) {
-                    case (byte)Thing.Type.TouchSensor:
-                        new TouchSensor(sender, msg.thingId);
-                        break;
-                }
-            }
-
-            if (thing == null)
-                thing = new Thing(sender, msg.thingType, msg.thingId);
 
             if (msg.parentId != 0) {
                 thing.parent = sender.Get(msg.parentId);
@@ -139,6 +130,14 @@ namespace RoboidControl {
             }
         }
 
+        protected virtual Thing ProcessNewThing(Participant sender, ThingMsg msg) {
+            return msg.thingType switch {
+                Thing.Type.TouchSensor => new TouchSensor(sender, msg.thingId),
+                Thing.Type.DifferentialDrive => new DifferentialDrive(sender, msg.thingId),
+                _ => new Thing(sender, msg.thingType, msg.thingId),
+            };
+
+        }
 
         #endregion Receive
 

src/Things/DifferentialDrive.cs

@@ -17,7 +17,19 @@ namespace RoboidControl {
         /// <param name="owner">The owning participant</param>
         /// <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 participant, byte thingId = 0, bool invokeEvent = true) : base(participant, Type.DifferentialDrive, thingId, invokeEvent) { }
+        public DifferentialDrive(Participant owner, byte thingId = 0, bool invokeEvent = true) : base(owner, Type.DifferentialDrive, thingId, invokeEvent) {
+            Thing leftWheel = new(this) {
+                name = "Left Wheel"
+            };
+            Thing 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>
         /// Create a new child differential drive
         /// </summary>
@@ -92,17 +104,43 @@ namespace RoboidControl {
         }
 
         /// @brief The radius of a wheel in meters
-        protected float wheelRadius = 1.0f;
+        public float wheelRadius = 1.0f;
         /// @brief The distance between the wheels in meters
-        protected float wheelSeparation = 1.0f;
+        public float wheelSeparation = 1.0f;
 
         /// @brief Convert revolutions per second to meters per second
         protected float rpsToMs = 1.0f;
 
         /// @brief The left wheel
-        protected Thing leftWheel = null;
+        public Thing leftWheel = null;
         /// @brief The right wheel
-        protected Thing rightWheel = null;
+        public Thing rightWheel = null;
+
+        bool sendBinary = false;
+        public override byte[] GenerateBinary() {
+            if (!sendBinary)
+                return System.Array.Empty<byte>();
+
+            byte[] data = new byte[6];
+            byte ix = 0;
+            data[ix++] = leftWheel.id;
+            data[ix++] = rightWheel.id;
+            LowLevelMessages.SendFloat16(data, ref ix, wheelRadius);
+            LowLevelMessages.SendFloat16(data, ref ix, wheelSeparation);
+            sendBinary = false;
+            return data;
+        }
+
+        public override void ProcessBinary(byte[] data) {
+            byte ix = 0;
+            byte leftWheelId = data[ix++];
+            this.leftWheel = this.owner.Get(leftWheelId);
+            byte rightWheelId = data[ix++];
+            this.rightWheel = this.owner.Get(rightWheelId);
+            this.wheelRadius = LowLevelMessages.ReceiveFloat16(data, ref ix);
+            this.wheelSeparation = LowLevelMessages.ReceiveFloat16(data, ref ix);
+            this.updateQueue.Enqueue(new UpdateEvent(BinaryMsg.Id));
+        }
     };
 
 }  // namespace RoboidControl

src/Things/TouchSensor.cs

@@ -24,7 +24,9 @@ namespace RoboidControl {
         /// <param name="parent">The parent thing</param>
         /// <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 TouchSensor(Thing parent, byte thingId = 0, bool invokeEvent = true) : base(parent, Type.TouchSensor, thingId, invokeEvent) { }
+        public TouchSensor(Thing parent, byte thingId = 0, bool invokeEvent = true) : base(parent, Type.TouchSensor, thingId, invokeEvent) {
+            this.name = "TouchSensor";
+         }
 
         /// <summary>
         /// Value which is true when the sensor is touching something, false otherwise