diff --git a/Sources/IoT-Simulator-Core/IoT_Simulator_Core.swift b/Sources/IoT-Simulator-Core/IoT_Simulator_Core.swift
index 0b8f75a..3c7beda 100644
--- a/Sources/IoT-Simulator-Core/IoT_Simulator_Core.swift
+++ b/Sources/IoT-Simulator-Core/IoT_Simulator_Core.swift
@@ -14,7 +14,12 @@ public actor IoTSimulatorCore {
         IoTSimulatorCore.enviroments[environment.location] = environment
     }
 
-    public static func addDevice(location: String, device: EdgeDeviceP) throws {
+    public static func addDevice(
+        location: String,
+        device: EdgeDeviceP,
+        success: sending @escaping (_ msg: Data) throws -> Void,
+        failure: sending @escaping () -> Void
+    ) throws {
         if let environment = IoTSimulatorCore.enviroments[location] {
             IoTSimulatorCore.devices["\(device.deviceID)"] = device
 
@@ -25,11 +30,9 @@ public actor IoTSimulatorCore {
             IoTSimulatorCore.env_dev[location]!.insert(device.deviceID)
 
             // schedule work
-            let task = IoTSimulatorCore.schedule(envID: environment.location, deviceID: device.deviceID) { msg in
-                print("\(msg)\n\n")
-            } failure: {
-                print("Something is wrong")
-            }
+            let task = IoTSimulatorCore.schedule(
+                envID: environment.location, deviceID: device.deviceID, success: success,
+                failure: failure)
             IoTSimulatorCore.dev_tasks["\(device.deviceID)"] = task
 
         } else {
@@ -42,6 +45,12 @@ public actor IoTSimulatorCore {
         return IoTSimulatorCore.enviroments[name]
     }
 
+    public static func addPhysicalData(environmentName: String, physicalData: PhysicalData) {
+        if let environment = getEnv(name: environmentName) {
+            environment.setPhysicalData(physicalData.type, physicalData)
+        }
+    }
+
     public static func getDev(devID: UInt128) -> EdgeDeviceP? {
         return IoTSimulatorCore.devices["\(devID)"]
     }
@@ -56,27 +65,57 @@ public actor IoTSimulatorCore {
         }
     }
 
+    public static func stopDevice(devID: UInt128) -> Bool {
+        if let task = IoTSimulatorCore.dev_tasks["\(devID)"] {
+            task.cancel()
+            return true
+        }
+        return false
+    }
 
+    public static func toggleSensor(devID: UInt128, sensorID: Int) -> Bool {
+
+        // UGLY: Should throw
+        if IoTSimulatorCore.getDev(devID: devID) == nil {
+            return false 
+        }
+
+        // FIXME: Should it throw?
+        if IoTSimulatorCore.getDev(devID: devID)!.deviceType != .EDGE_SENSOR {
+            return false
+        }
+
+        let device = IoTSimulatorCore.getDev(devID: devID)! as! EdgeDevice
+
+        // UGLY: It should throw
+        if device.sensors.count <= sensorID {
+            return false 
+        }
+
+        device.sensors[sensorID]!.faulty = !device.sensors[sensorID]!.faulty
+
+        return true
+    }
 
     private static func schedule(
         envID: sending String,
         deviceID: UInt128,
         success: sending @escaping (_ msg: Data) throws -> Void,
         failure: sending @escaping () -> Void
-    )  -> Task<(), Never> {
-        let _devID : String = "\(deviceID)"
+    ) -> Task<(), Never> {
+        let _devID: String = "\(deviceID)"
         return Task {
 
             var notCancelled: Bool = true
 
             let dev = IoTSimulatorCore.getDev(devID: _devID)!
             let env = IoTSimulatorCore.getEnv(name: envID)!
-            
+
             while notCancelled {
-                    print("Device: \(dev.deviceID)")
+                print("Device: \(dev.deviceID)")
                 do {
                     let message = try dev.work(envrionment: env)
-                    
+
                     try success(message)
                 } catch {
                     failure()
@@ -86,13 +125,13 @@ public actor IoTSimulatorCore {
                     try await Task.sleep(nanoseconds: UInt64(dev.dutyCicle) * UInt64(1E6))
                 } catch {
                     notCancelled = false
-                    
+
                 }
-                
+
             }
 
             print("Bye, Bye, \(dev.deviceID)\n\n")
-            
+
         }
     }
 
diff --git a/Tests/IoT-Simulator-CoreTests/IoTCore-Tests.swift b/Tests/IoT-Simulator-CoreTests/IoTCore-Tests.swift
index 09344c7..4303aa7 100644
--- a/Tests/IoT-Simulator-CoreTests/IoTCore-Tests.swift
+++ b/Tests/IoT-Simulator-CoreTests/IoTCore-Tests.swift
@@ -58,8 +58,22 @@ import MessageUtils
         privateKey: privateKey
     )
 
-    try IoTSimulatorCore.addDevice(location: "Delta", device: dev)
-    try IoTSimulatorCore.addDevice(location: "Delta", device: dev2)
+    try IoTSimulatorCore.addDevice(location: "Delta", device: dev, success: { msg in 
+                print(msg)
+                let _signedMessage = try! deserializeV1(serializedData: msg)
+                print(_signedMessage.toString())
+            }, 
+            failure: {
+                print("Something went wrong")
+            })
+    try IoTSimulatorCore.addDevice(location: "Delta", device: dev2, success: { msg in 
+                print(msg)
+                let _signedMessage = try! deserializeV1(serializedData: msg)
+                print(_signedMessage.toString())
+            }, 
+            failure: {
+                print("Something went wrong")
+            })
 
     sleep(15)
 
@@ -102,7 +116,18 @@ import MessageUtils
             privateKey: privateKey
         )
 
-        try IoTSimulatorCore.addDevice(location: "Delta", device: dev)
+        try IoTSimulatorCore.addDevice(
+            location: "Delta", 
+            device: dev,
+            success: { msg in 
+                print(msg)
+                let _signedMessage = try! deserializeV1(serializedData: msg)
+                print(_signedMessage.toString())
+            }, 
+            failure: {
+                print("Something went wrong")
+            }
+        )
     }
 
     let _sleep = 15
@@ -116,3 +141,65 @@ import MessageUtils
     
 
 }
+
+@Test func stressLoop2() async throws {
+
+    let devices: UInt128 = 1
+
+    let env = PhysicalEnvironment("Delta")
+    let truth = PhysicalData(.Temperature, 22)
+
+    env.setPhysicalData(DataType.Temperature, truth)
+
+    IoTSimulatorCore.addEnv(environment: env)
+
+    let signKeyPath = "./Private/privateKey.pem"
+
+    let privateKey = try pem2_P256key(filePath: signKeyPath)
+
+    for i: UInt128 in 0..<devices {
+
+        let dev: EdgeDevice = EdgeDevice(
+            deviceID: i,
+            dataType: .Temperature,
+            disconnected: false,
+            location: Location(x: 20, y: 10, z: 0),
+            dutyCicle: 200 + UInt.random(in: 200...1000),
+            sensors: [
+                0: RealSensor(
+                    sensorID: 0, sensorType: .Temperature, faulty: false, meanNoise: 1, stdNoise: 3,
+                    quantizationBits: 3),
+                1: RealSensor(
+                    sensorID: 1, sensorType: .Temperature, faulty: false, meanNoise: 1, stdNoise: 3,
+                    quantizationBits: 3),
+                2: RealSensor(
+                    sensorID: 2, sensorType: .Temperature, faulty: false, meanNoise: 1, stdNoise: 3,
+                    quantizationBits: 3),
+            ],
+            privateKey: privateKey
+        )
+
+        try IoTSimulatorCore.addDevice(location: "Delta", device: dev, success: { msg in 
+                print(msg)
+                let _signedMessage = try! deserializeV1(serializedData: msg)
+                print(_signedMessage.toString())
+            }, 
+            failure: {
+                print("Something went wrong")
+            })
+    }
+
+    let _sleep = 15
+
+    for i in 0..<_sleep {
+        print("Hi, at \(i)s\n\n")
+        sleep(1)
+
+        IoTSimulatorCore.toggleSensor(devID: 0, sensorID: 0)
+
+    }
+    print("NUKE EM ALLLLLLLLLL!!!!!\n\n")
+    IoTSimulatorCore.nukeAll()
+    
+
+}