Complete rework of PID demo and underlying devices

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/ConstructorElement.kt

@@ -3,11 +3,13 @@ package space.kscience.controls.constructor
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.*
+import kotlinx.datetime.Instant
 import space.kscience.controls.api.Device
 import space.kscience.controls.manager.ClockManager
 import space.kscience.dataforge.context.ContextAware
 import space.kscience.dataforge.context.request
 import kotlin.time.Duration
+import kotlin.time.Duration.Companion.milliseconds
 
 /**
  * A binding that is used to describe device functionality
@@ -36,7 +38,7 @@ public class ConnectionConstrucorElement(
 ) : ConstructorElement
 
 public class ModelConstructorElement(
-    public val model: ModelConstructor
+    public val model: ModelConstructor,
 ) : ConstructorElement
 
 
@@ -77,15 +79,15 @@ public interface StateContainer : ContextAware, CoroutineScope {
 /**
  * Register a [state] in this container. The state is not registered as a device property if [this] is a [DeviceConstructor]
  */
-public fun <T, D : DeviceState<T>> StateContainer.state(state: D): D {
+public fun <T, D : DeviceState<T>> StateContainer.registerState(state: D): D {
     registerElement(StateConstructorElement(state))
     return state
 }
 
 /**
- * Create a register a [MutableDeviceState] with a given [converter]
+ * Create a register a [MutableDeviceState]
  */
-public fun <T> StateContainer.stateOf(initialValue: T): MutableDeviceState<T> = state(
+public fun <T> StateContainer.stateOf(initialValue: T): MutableDeviceState<T> = registerState(
     MutableDeviceState(initialValue)
 )
 
@@ -97,23 +99,53 @@ public fun <T : ModelConstructor> StateContainer.model(model: T): T {
 /**
  * Create and register a timer state.
  */
-public fun StateContainer.timer(tick: Duration): TimerState = state(TimerState(context.request(ClockManager), tick))
+public fun StateContainer.timer(tick: Duration): TimerState =
+    registerState(TimerState(context.request(ClockManager), tick))
 
+/**
+ * Register a new timer and perform [block] on its change
+ */
+public fun StateContainer.onTimer(
+    tick: Duration,
+    writes: Collection<DeviceState<*>> = emptySet(),
+    reads: Collection<DeviceState<*>> = emptySet(),
+    block: suspend (prev: Instant, next: Instant) -> Unit,
+): Job = timer(tick).onChange(writes = writes, reads = reads, onChange = block)
+
+public enum class DefaultTimer(public val duration: Duration){
+    REALTIME(5.milliseconds),
+    VERY_FAST(10.milliseconds),
+    FAST(20.milliseconds),
+    MEDIUM(50.milliseconds),
+    SLOW(100.milliseconds),
+    VERY_SLOW(500.milliseconds),
+}
+
+/**
+ * Perform an action on default timer
+ */
+public fun StateContainer.onTimer(
+    defaultTimer: DefaultTimer = DefaultTimer.FAST,
+    writes: Collection<DeviceState<*>> = emptySet(),
+    reads: Collection<DeviceState<*>> = emptySet(),
+    block: suspend (prev: Instant, next: Instant) -> Unit,
+): Job = timer(defaultTimer.duration).onChange(writes = writes, reads = reads, onChange = block)
+//TODO implement timer pooling
 
 public fun <T, R> StateContainer.mapState(
     origin: DeviceState<T>,
     transformation: (T) -> R,
-): DeviceStateWithDependencies<R> = state(DeviceState.map(origin, transformation))
+): DeviceStateWithDependencies<R> = registerState(DeviceState.map(origin, transformation))
 
 
 public fun <T, R> StateContainer.flowState(
     origin: DeviceState<T>,
     initialValue: R,
-    transformation: suspend FlowCollector<R>.(T) -> Unit
+    transformation: suspend FlowCollector<R>.(T) -> Unit,
 ): DeviceStateWithDependencies<R> {
     val state = MutableDeviceState(initialValue)
     origin.valueFlow.transform(transformation).onEach { state.value = it }.launchIn(this)
-    return state(state.withDependencies(setOf(origin)))
+    return registerState(state.withDependencies(setOf(origin)))
 }
 
 /**
@@ -123,7 +155,7 @@ public fun <T1, T2, R> StateContainer.combineState(
     first: DeviceState<T1>,
     second: DeviceState<T2>,
     transformation: (T1, T2) -> R,
-): DeviceState<R> = state(DeviceState.combine(first, second, transformation))
+): DeviceState<R> = registerState(DeviceState.combine(first, second, transformation))
 
 /**
  * Create and start binding between [sourceState] and [targetState]. Changes made to [sourceState] are automatically

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/DeviceState.kt

@@ -6,12 +6,14 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.UnitsOfMeasurement
 import kotlin.reflect.KProperty
 
 /**
  * An observable state of a device
  */
-public interface DeviceState<T> {
+public interface DeviceState<out T> {
     public val value: T
 
     public val valueFlow: Flow<T>
@@ -49,7 +51,7 @@ public interface DeviceStateWithDependencies<T> : DeviceState<T> {
 }
 
 public fun <T> DeviceState<T>.withDependencies(
-    dependencies: Collection<DeviceState<*>>
+    dependencies: Collection<DeviceState<*>>,
 ): DeviceStateWithDependencies<T> = object : DeviceStateWithDependencies<T>, DeviceState<T> by this {
     override val dependencies: Collection<DeviceState<*>> = dependencies
 }
@@ -72,6 +74,16 @@ public fun <T, R> DeviceState.Companion.map(
 
 public fun <T, R> DeviceState<T>.map(mapper: (T) -> R): DeviceStateWithDependencies<R> = DeviceState.map(this, mapper)
 
+public fun DeviceState<out NumericalValue<out UnitsOfMeasurement>>.values(): DeviceState<Double> = object : DeviceState<Double> {
+    override val value: Double
+        get() = this@values.value.value
+
+    override val valueFlow: Flow<Double>
+        get() = this@values.valueFlow.map { it.value }
+
+    override fun toString(): String = this@values.toString()
+}
+
 /**
  * Combine two device states into one read-only [DeviceState]. Only the latest value of each state is used.
  */

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/devices/Drive.kt

@@ -0,0 +1,18 @@
+package space.kscience.controls.constructor.devices
+
+import space.kscience.controls.constructor.DeviceConstructor
+import space.kscience.controls.constructor.MutableDeviceState
+import space.kscience.controls.constructor.property
+import space.kscience.controls.constructor.units.NewtonsMeters
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.numerical
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.meta.MetaConverter
+
+
+public class Drive(
+    context: Context,
+    force: MutableDeviceState<NumericalValue<NewtonsMeters>> = MutableDeviceState(NumericalValue(0)),
+) : DeviceConstructor(context) {
+    public val force: MutableDeviceState<NumericalValue<NewtonsMeters>> by property(MetaConverter.numerical(), force)
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/devices/EncoderDevice.kt

@@ -0,0 +1,20 @@
+package space.kscience.controls.constructor.devices
+
+import space.kscience.controls.constructor.DeviceConstructor
+import space.kscience.controls.constructor.DeviceState
+import space.kscience.controls.constructor.property
+import space.kscience.controls.constructor.units.Degrees
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.numerical
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.meta.MetaConverter
+
+/**
+ * An encoder that can read an angle
+ */
+public class EncoderDevice(
+    context: Context,
+    position: DeviceState<NumericalValue<Degrees>>
+) : DeviceConstructor(context) {
+    public val position: DeviceState<NumericalValue<Degrees>> by property(MetaConverter.numerical<Degrees>(), position)
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/devices/LimitSwitch.kt

@@ -1,4 +1,4 @@
-package space.kscience.controls.constructor.library
+package space.kscience.controls.constructor.devices
 
 import space.kscience.controls.constructor.DeviceConstructor
 import space.kscience.controls.constructor.DeviceState
@@ -7,7 +7,6 @@ import space.kscience.controls.constructor.registerAsProperty
 import space.kscience.controls.constructor.units.Direction
 import space.kscience.controls.constructor.units.NumericalValue
 import space.kscience.controls.constructor.units.UnitsOfMeasurement
-import space.kscience.controls.constructor.units.compareTo
 import space.kscience.controls.spec.DevicePropertySpec
 import space.kscience.controls.spec.DeviceSpec
 import space.kscience.controls.spec.booleanProperty

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/devices/LinearDrive.kt

@@ -0,0 +1,38 @@
+package space.kscience.controls.constructor.devices
+
+import space.kscience.controls.constructor.*
+import space.kscience.controls.constructor.models.PidParameters
+import space.kscience.controls.constructor.models.PidRegulator
+import space.kscience.controls.constructor.units.Meters
+import space.kscience.controls.constructor.units.NewtonsMeters
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.numerical
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.MetaConverter
+
+public class LinearDrive(
+    drive: Drive,
+    start: LimitSwitch,
+    end: LimitSwitch,
+    position: DeviceState<NumericalValue<Meters>>,
+    pidParameters: PidParameters,
+    context: Context = drive.context,
+    meta: Meta = Meta.EMPTY,
+) : DeviceConstructor(context, meta) {
+
+    public val position: DeviceState<NumericalValue<Meters>> by property(MetaConverter.numerical(), position)
+
+    public val drive: Drive by device(drive)
+    public val pid: PidRegulator<Meters, NewtonsMeters>  = model(
+        PidRegulator(
+            context = context,
+            position = position,
+            output = drive.force,
+            pidParameters = pidParameters
+        )
+    )
+
+    public val startLimit: LimitSwitch by device(start)
+    public val endLimit: LimitSwitch by device(end)
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/devices/StepDrive.kt

@@ -0,0 +1,61 @@
+package space.kscience.controls.constructor.devices
+
+import kotlinx.coroutines.launch
+import space.kscience.controls.constructor.*
+import space.kscience.controls.constructor.units.Degrees
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.plus
+import space.kscience.controls.constructor.units.times
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.meta.MetaConverter
+import kotlin.math.max
+import kotlin.math.min
+import kotlin.math.roundToInt
+import kotlin.time.DurationUnit
+
+/**
+ * A step drive
+ *
+ * @param speed ticks per second
+ * @param target target ticks state
+ * @param writeTicks a hardware callback
+ */
+public class StepDrive(
+    context: Context,
+    speed: MutableDeviceState<Double>,
+    target: MutableDeviceState<Int> = MutableDeviceState(0),
+    private val writeTicks: suspend (ticks: Int, speed: Double) -> Unit,
+) : DeviceConstructor(context) {
+
+    public val target: MutableDeviceState<Int> by property(MetaConverter.int, target)
+
+    public val speed: MutableDeviceState<Double> by property(MetaConverter.double, speed)
+
+    private val positionState = stateOf(target.value)
+
+    public val position: DeviceState<Int> by property(MetaConverter.int, positionState)
+
+    private val ticker = onTimer { prev, next ->
+        val tickSpeed = speed.value
+        val timeDelta = (next - prev).toDouble(DurationUnit.SECONDS)
+        val ticksDelta: Int = target.value - position.value
+        val steps: Int = when {
+            ticksDelta > 0 -> min(ticksDelta, (timeDelta * tickSpeed).roundToInt())
+            ticksDelta < 0 -> max(ticksDelta, (timeDelta * tickSpeed).roundToInt())
+            else -> return@onTimer
+        }
+        launch {
+            writeTicks(steps, tickSpeed)
+            positionState.value += steps
+        }
+    }
+}
+
+/**
+ * Compute a state using given tick-to-angle transformation
+ */
+public fun StepDrive.angle(
+    zero: NumericalValue<Degrees>,
+    step: NumericalValue<Degrees>,
+): DeviceState<NumericalValue<Degrees>> = position.map { zero + it * step }
+

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/library/DoubleInRangeState.kt

@@ -1,57 +0,0 @@
-package space.kscience.controls.constructor.library
-
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.map
-import space.kscience.controls.constructor.DeviceState
-import space.kscience.controls.constructor.MutableDeviceState
-import space.kscience.controls.constructor.map
-
-/**
- *  A state describing a [Double] value in the [range]
- */
-public open class DoubleInRangeState(
-    private val input: DeviceState<Double>,
-    public val range: ClosedFloatingPointRange<Double>,
-) : DeviceState<Double> {
-
-    override val valueFlow: Flow<Double> get() = input.valueFlow.map { it.coerceIn(range) }
-
-    override val value: Double get() = input.value.coerceIn(range)
-
-    /**
-     * A state showing that the range is on its lower boundary
-     */
-    public val atStart: DeviceState<Boolean> = input.map { it <= range.start }
-
-    /**
-     * A state showing that the range is on its higher boundary
-     */
-    public val atEnd: DeviceState<Boolean> = input.map { it >= range.endInclusive }
-
-    override fun toString(): String = "DoubleRangeState(value=${value},range=$range)"
-}
-
-public class MutableDoubleInRangeState(
-    private val mutableInput: MutableDeviceState<Double>,
-    range: ClosedFloatingPointRange<Double>
-) : DoubleInRangeState(mutableInput, range), MutableDeviceState<Double> {
-    override var value: Double
-        get() = super.value
-        set(value) {
-            mutableInput.value = value.coerceIn(range)
-        }
-}
-
-public fun MutableDoubleInRangeState(
-    initialValue: Double,
-    range: ClosedFloatingPointRange<Double>
-): MutableDoubleInRangeState = MutableDoubleInRangeState(MutableDeviceState(initialValue),range)
-
-
-public fun DeviceState<Double>.coerceIn(
-    range: ClosedFloatingPointRange<Double>
-): DoubleInRangeState = DoubleInRangeState(this, range)
-
-public fun MutableDeviceState<Double>.coerceIn(
-    range: ClosedFloatingPointRange<Double>
-): MutableDoubleInRangeState = MutableDoubleInRangeState(this, range)

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/library/Drive.kt

@@ -1,102 +0,0 @@
-package space.kscience.controls.constructor.library
-
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.delay
-import kotlinx.coroutines.isActive
-import kotlinx.coroutines.launch
-import space.kscience.controls.api.Device
-import space.kscience.controls.constructor.MutableDeviceState
-import space.kscience.controls.constructor.propertyAsState
-import space.kscience.controls.manager.clock
-import space.kscience.controls.spec.*
-import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.context.Factory
-import space.kscience.dataforge.meta.MetaConverter
-import space.kscience.dataforge.meta.double
-import space.kscience.dataforge.meta.get
-import kotlin.math.pow
-import kotlin.time.Duration.Companion.milliseconds
-import kotlin.time.DurationUnit
-
-/**
- * A classic drive regulated by force with encoder
- */
-public interface Drive : Device {
-    /**
-     * Get or set drive force or momentum
-     */
-    public var force: Double
-
-    /**
-     * Current position value
-     */
-    public val position: Double
-
-    public companion object : DeviceSpec<Drive>() {
-        public val force: MutableDevicePropertySpec<Drive, Double> by Drive.mutableProperty(
-            MetaConverter.double,
-            Drive::force
-        )
-
-        public val position: DevicePropertySpec<Drive, Double> by doubleProperty { position }
-    }
-}
-
-/**
- * A virtual drive
- */
-public class VirtualDrive(
-    context: Context,
-    private val mass: Double,
-    public val positionState: MutableDeviceState<Double>,
-) : Drive, DeviceBySpec<Drive>(Drive, context) {
-
-    private val dt = meta["time.step"].double?.milliseconds ?: 5.milliseconds
-    private val clock = context.clock
-
-    override var force: Double = 0.0
-
-    override val position: Double get() = positionState.value
-
-    public var velocity: Double = 0.0
-        private set
-
-    private var updateJob: Job? = null
-
-    override suspend fun onStart() {
-        updateJob = launch {
-            var lastTime = clock.now()
-            while (isActive) {
-                delay(dt)
-                val realTime = clock.now()
-                val dtSeconds = (realTime - lastTime).toDouble(DurationUnit.SECONDS)
-
-                //set last time and value to new values
-                lastTime = realTime
-
-                // compute new value based on velocity and acceleration from the previous step
-                positionState.value += velocity * dtSeconds + force / mass * dtSeconds.pow(2) / 2
-                propertyChanged(Drive.position, positionState.value)
-
-                // compute new velocity based on acceleration on the previous step
-                velocity += force / mass * dtSeconds
-            }
-        }
-    }
-
-    override suspend fun onStop() {
-        updateJob?.cancel()
-    }
-
-    public companion object {
-        public fun factory(
-            mass: Double,
-            positionState: MutableDeviceState<Double>,
-        ): Factory<Drive> = Factory { context, _ ->
-            VirtualDrive(context, mass, positionState)
-        }
-    }
-}
-
-public fun Drive.stateOfForce(initialForce: Double = 0.0): MutableDeviceState<Double> =
-    propertyAsState(Drive.force, initialForce)

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/library/PidRegulator.kt

@@ -1,74 +0,0 @@
-package space.kscience.controls.constructor.library
-
-import kotlinx.coroutines.delay
-import kotlinx.coroutines.isActive
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
-import space.kscience.controls.constructor.DeviceState
-import space.kscience.controls.constructor.MutableDeviceState
-import space.kscience.controls.constructor.state
-import space.kscience.controls.constructor.stateOf
-import space.kscience.controls.manager.clock
-import space.kscience.dataforge.context.Context
-import kotlin.time.Duration
-import kotlin.time.DurationUnit
-
-
-/**
- * Pid regulator parameters
- */
-public data class PidParameters(
-    val kp: Double,
-    val ki: Double,
-    val kd: Double,
-    val timeStep: Duration,
-)
-
-/**
- * A PID regulator
- */
-public class PidRegulator(
-    context: Context,
-    private val position: DeviceState<Double>,
-    public var pidParameters: PidParameters, // TODO expose as property
-    output: MutableDeviceState<Double> = MutableDeviceState(0.0),
-) : Regulator<Double>(context) {
-
-    override val target: MutableDeviceState<Double> = stateOf(0.0)
-    override val output: MutableDeviceState<Double> = state(output)
-
-    private var lastPosition: Double = target.value
-
-    private var integral: Double = 0.0
-
-    private val mutex = Mutex()
-
-    private var lastTime = clock.now()
-
-    private val updateJob = launch {
-        while (isActive) {
-            delay(pidParameters.timeStep)
-            mutex.withLock {
-                val realTime = clock.now()
-                val delta = target.value - position.value
-                val dtSeconds = (realTime - lastTime).toDouble(DurationUnit.SECONDS)
-                integral += delta * dtSeconds
-                val derivative = (position.value - lastPosition) / dtSeconds
-
-                //set last time and value to new values
-                lastTime = realTime
-                lastPosition = position.value
-
-                output.value = pidParameters.kp * delta + pidParameters.ki * integral + pidParameters.kd * derivative
-            }
-        }
-    }
-}
-
-//
-//public fun DeviceGroup.pid(
-//    name: String,
-//    drive: Drive,
-//    pidParameters: PidParameters,
-//): PidRegulator = install(name.parseAsName(), PidRegulator(drive, pidParameters))

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/library/Regulator.kt

@@ -1,17 +0,0 @@
-package space.kscience.controls.constructor.library
-
-import space.kscience.controls.constructor.DeviceConstructor
-import space.kscience.controls.constructor.DeviceState
-import space.kscience.controls.constructor.MutableDeviceState
-import space.kscience.dataforge.context.Context
-
-
-/**
- * A regulator with target value and current position
- */
-public abstract class Regulator<T>(context: Context) : DeviceConstructor(context) {
-
-    public abstract val target: MutableDeviceState<T>
-
-    public abstract val output: DeviceState<T>
-}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/library/StepDrive.kt

@@ -1,33 +0,0 @@
-package space.kscience.controls.constructor.library
-
-import space.kscience.controls.constructor.DeviceState
-import space.kscience.controls.constructor.MutableDeviceState
-import space.kscience.controls.constructor.combineState
-import space.kscience.controls.constructor.property
-import space.kscience.controls.constructor.units.*
-import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.meta.MetaConverter
-
-/**
- * A step drive regulated by [input]
- */
-public class StepDrive(
-    context: Context,
-    public val step: NumericalValue<Degrees>,
-    public val zero: NumericalValue<Degrees> = NumericalValue(0.0),
-    direction: Direction = Direction.UP,
-    input: MutableDeviceState<Int> = MutableDeviceState(0),
-    hold: MutableDeviceState<Boolean> = MutableDeviceState(false)
-) : Transmission<Int, NumericalValue<Degrees>>(context) {
-
-    override val input: MutableDeviceState<Int> by property(MetaConverter.int, input)
-
-    public val hold: MutableDeviceState<Boolean> by property(MetaConverter.boolean, hold)
-
-    override val output: DeviceState<NumericalValue<Degrees>> = combineState(
-        input, hold
-    ) { input, hold ->
-        //TODO use hold parameter
-        zero + input * direction.coef * step
-    }
-}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/library/Transmission.kt

@@ -1,33 +0,0 @@
-package space.kscience.controls.constructor.library
-
-import space.kscience.controls.constructor.DeviceConstructor
-import space.kscience.controls.constructor.DeviceState
-import space.kscience.controls.constructor.MutableDeviceState
-import space.kscience.controls.constructor.flowState
-import space.kscience.dataforge.context.Context
-
-
-/**
- * A model for a device that converts one type of physical quantity to another type
- */
-public abstract class Transmission<T, R>(context: Context) : DeviceConstructor(context) {
-    public abstract val input: MutableDeviceState<T>
-    public abstract val output: DeviceState<R>
-
-    public companion object {
-        /**
-         * Create a device that is a hard connection between two physical quantities
-         */
-        public suspend fun <T, R> direct(
-            context: Context,
-            input: MutableDeviceState<T>,
-            transform: suspend (T) -> R
-        ): Transmission<T, R> {
-            val initialValue = transform(input.value)
-            return object : Transmission<T, R>(context) {
-                override val input: MutableDeviceState<T> = input
-                override val output: DeviceState<R> = flowState(input, initialValue) { emit(transform(it)) }
-            }
-        }
-    }
-}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/models/Inertia.kt

@@ -0,0 +1,104 @@
+package space.kscience.controls.constructor.models
+
+import space.kscience.controls.constructor.*
+import space.kscience.controls.constructor.units.*
+import space.kscience.dataforge.context.Context
+import kotlin.math.pow
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.DurationUnit
+
+/**
+ * A model for inertial movement. Both linear and angular
+ */
+public class Inertia<U : UnitsOfMeasurement, V : UnitsOfMeasurement>(
+    context: Context,
+    force: DeviceState<Double>, //TODO add system unit sets
+    inertia: Double,
+    public val position: MutableDeviceState<NumericalValue<U>>,
+    public val velocity: MutableDeviceState<NumericalValue<V>>,
+    timerPrecision: Duration = 10.milliseconds,
+) : ModelConstructor(context) {
+
+    init {
+        registerState(position)
+        registerState(velocity)
+    }
+
+    private val movementTimer = timer(timerPrecision)
+
+    private var currentForce = force.value
+
+    private val movement = movementTimer.onChange { prev, next ->
+        val dtSeconds = (next - prev).toDouble(DurationUnit.SECONDS)
+
+        // compute new value based on velocity and acceleration from the previous step
+        position.value += NumericalValue(velocity.value.value * dtSeconds + currentForce / inertia * dtSeconds.pow(2) / 2)
+
+        // compute new velocity based on acceleration on the previous step
+        velocity.value += NumericalValue(currentForce / inertia * dtSeconds)
+        currentForce = force.value
+    }
+
+    public companion object {
+        /**
+         * Linear inertial model with [force] in newtons and [mass] in kilograms
+         */
+        public fun linear(
+            context: Context,
+            force: DeviceState<NumericalValue<Newtons>>,
+            mass: NumericalValue<Kilograms>,
+            position: MutableDeviceState<NumericalValue<Meters>>,
+            velocity: MutableDeviceState<NumericalValue<MetersPerSecond>> = MutableDeviceState(NumericalValue(0.0)),
+        ): Inertia<Meters, MetersPerSecond> = Inertia(
+            context = context,
+            force = force.values(),
+            inertia = mass.value,
+            position = position,
+            velocity = velocity
+        )
+//
+//
+//        public fun linear(
+//            context: Context,
+//            force: DeviceState<NumericalValue<Newtons>>,
+//            mass: NumericalValue<Kilograms>,
+//            initialPosition: NumericalValue<Meters>,
+//            initialVelocity: NumericalValue<MetersPerSecond> = NumericalValue(0),
+//        ): Inertia<Meters, MetersPerSecond> = Inertia(
+//            context = context,
+//            force = force.values(),
+//            inertia = mass.value,
+//            position = MutableDeviceState(initialPosition),
+//            velocity = MutableDeviceState(initialVelocity)
+//        )
+
+        public fun circular(
+            context: Context,
+            force: DeviceState<NumericalValue<NewtonsMeters>>,
+            momentOfInertia: NumericalValue<KgM2>,
+            position: MutableDeviceState<NumericalValue<Degrees>>,
+            velocity: MutableDeviceState<NumericalValue<DegreesPerSecond>> = MutableDeviceState(NumericalValue(0.0)),
+        ): Inertia<Degrees, DegreesPerSecond> = Inertia(
+            context = context,
+            force = force.values(),
+            inertia = momentOfInertia.value,
+            position = position,
+            velocity = velocity
+        )
+//
+//        public fun circular(
+//            context: Context,
+//            force: DeviceState<NumericalValue<NewtonsMeters>>,
+//            momentOfInertia: NumericalValue<KgM2>,
+//            initialPosition: NumericalValue<Degrees>,
+//            initialVelocity: NumericalValue<DegreesPerSecond> = NumericalValue(0),
+//        ): Inertia<Degrees, DegreesPerSecond> = Inertia(
+//            context = context,
+//            force = force.values(),
+//            inertia = momentOfInertia.value,
+//            position = MutableDeviceState(initialPosition),
+//            velocity = MutableDeviceState(initialVelocity)
+//        )
+    }
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/models/PidRegulator.kt

@@ -0,0 +1,73 @@
+package space.kscience.controls.constructor.models
+
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import space.kscience.controls.constructor.*
+import space.kscience.controls.constructor.units.*
+import space.kscience.controls.manager.clock
+import space.kscience.dataforge.context.Context
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.DurationUnit
+
+
+/**
+ * Pid regulator parameters
+ */
+public data class PidParameters(
+    val kp: Double,
+    val ki: Double,
+    val kd: Double,
+    val timeStep: Duration = 10.milliseconds,
+)
+
+/**
+ * A PID regulator
+ *
+ * @param P units of position values
+ * @param O units of output values
+ */
+public class PidRegulator<P : UnitsOfMeasurement, O : UnitsOfMeasurement>(
+    context: Context,
+    private val position: DeviceState<NumericalValue<P>>,
+    public var pidParameters: PidParameters, // TODO expose as property
+    output: MutableDeviceState<NumericalValue<O>> = MutableDeviceState(NumericalValue(0.0)),
+    private val convertOutput: (NumericalValue<P>) -> NumericalValue<O> = { NumericalValue(it.value) },
+) : ModelConstructor(context) {
+
+    public val target: MutableDeviceState<NumericalValue<P>> = stateOf(NumericalValue(0.0))
+    public val output: MutableDeviceState<NumericalValue<O>> = registerState(output)
+
+    private val updateJob = launch {
+        var lastPosition: NumericalValue<P> = target.value
+
+        var integral: NumericalValue<P> = NumericalValue(0.0)
+
+        val mutex = Mutex()
+
+        val clock = context.clock
+
+        var lastTime = clock.now()
+
+        while (isActive) {
+            delay(pidParameters.timeStep)
+            mutex.withLock {
+                val realTime = clock.now()
+                val delta: NumericalValue<P> = target.value - position.value
+                val dtSeconds = (realTime - lastTime).toDouble(DurationUnit.SECONDS)
+                integral += delta * dtSeconds
+                val derivative = (position.value - lastPosition) / dtSeconds
+
+                //set last time and value to new values
+                lastTime = realTime
+                lastPosition = position.value
+
+                output.value =
+                    convertOutput(pidParameters.kp * delta + pidParameters.ki * integral + pidParameters.kd * derivative)
+            }
+        }
+    }
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/models/RangeState.kt

@@ -0,0 +1,68 @@
+package space.kscience.controls.constructor.models
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import space.kscience.controls.constructor.DeviceState
+import space.kscience.controls.constructor.MutableDeviceState
+import space.kscience.controls.constructor.map
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.UnitsOfMeasurement
+
+/**
+ *  A state describing a [T] value in the [range]
+ */
+public open class RangeState<T : Comparable<T>>(
+    private val input: DeviceState<T>,
+    public val range: ClosedRange<T>,
+) : DeviceState<T> {
+
+    override val valueFlow: Flow<T> get() = input.valueFlow.map { it.coerceIn(range) }
+
+    override val value: T get() = input.value.coerceIn(range)
+
+    /**
+     * A state showing that the range is on its lower boundary
+     */
+    public val atStart: DeviceState<Boolean> = input.map { it <= range.start }
+
+    /**
+     * A state showing that the range is on its higher boundary
+     */
+    public val atEnd: DeviceState<Boolean> = input.map { it >= range.endInclusive }
+
+    override fun toString(): String = "DoubleRangeState(value=${value},range=$range)"
+}
+
+public class MutableRangeState<T : Comparable<T>>(
+    private val mutableInput: MutableDeviceState<T>,
+    range: ClosedRange<T>,
+) : RangeState<T>(mutableInput, range), MutableDeviceState<T> {
+    override var value: T
+        get() = super.value
+        set(value) {
+            mutableInput.value = value.coerceIn(range)
+        }
+}
+
+public fun <T : Comparable<T>> MutableRangeState(
+    initialValue: T,
+    range: ClosedRange<T>,
+): MutableRangeState<T> = MutableRangeState<T>(MutableDeviceState(initialValue), range)
+
+public fun <U : UnitsOfMeasurement> MutableRangeState(
+    initialValue: Double,
+    range: ClosedRange<Double>,
+): MutableRangeState<NumericalValue<U>> = MutableRangeState(
+    initialValue = NumericalValue(initialValue),
+    range = NumericalValue<U>(range.start)..NumericalValue<U>(range.endInclusive)
+)
+
+
+public fun <T : Comparable<T>> DeviceState<T>.coerceIn(
+    range: ClosedFloatingPointRange<T>,
+): RangeState<T> = RangeState(this, range)
+
+
+public fun <T : Comparable<T>> MutableDeviceState<T>.coerceIn(
+    range: ClosedFloatingPointRange<T>,
+): MutableRangeState<T> = MutableRangeState(this, range)

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/models/Reducer.kt

@@ -0,0 +1,25 @@
+package space.kscience.controls.constructor.models
+
+import space.kscience.controls.constructor.*
+import space.kscience.controls.constructor.units.Degrees
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.units.times
+import space.kscience.dataforge.context.Context
+
+/**
+ * A reducer device used for simulations only (no public properties)
+ */
+public class Reducer(
+    context: Context,
+    public val ratio: Double,
+    public val input: DeviceState<NumericalValue<Degrees>>,
+    public val output: MutableDeviceState<NumericalValue<Degrees>>,
+) : ModelConstructor(context) {
+    init {
+        registerState(input)
+        registerState(output)
+        transformTo(input, output) {
+            it * ratio
+        }
+    }
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/models/ScrewDrive.kt

@@ -0,0 +1,22 @@
+package space.kscience.controls.constructor.models
+
+import space.kscience.controls.constructor.DeviceState
+import space.kscience.controls.constructor.ModelConstructor
+import space.kscience.controls.constructor.map
+import space.kscience.controls.constructor.units.Meters
+import space.kscience.controls.constructor.units.Newtons
+import space.kscience.controls.constructor.units.NewtonsMeters
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.dataforge.context.Context
+
+public class ScrewDrive(
+    context: Context,
+    public val leverage: NumericalValue<Meters>,
+) : ModelConstructor(context) {
+    public fun transformForce(
+        stateOfForce: DeviceState<NumericalValue<NewtonsMeters>>,
+    ): DeviceState<NumericalValue<Newtons>> = DeviceState.map(stateOfForce) {
+        NumericalValue(it.value * leverage.value)
+    }
+
+}

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/units/NumericalValue.kt

@@ -1,5 +1,8 @@
 package space.kscience.controls.constructor.units
 
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.MetaConverter
+import space.kscience.dataforge.meta.double
 import kotlin.jvm.JvmInline
 
 
@@ -7,31 +10,46 @@ import kotlin.jvm.JvmInline
  * A value without identity coupled to units of measurements.
  */
 @JvmInline
-public value class NumericalValue<U : UnitsOfMeasurement>(public val value: Double)
+public value class NumericalValue<U : UnitsOfMeasurement>(public val value: Double): Comparable<NumericalValue<U>> {
+    override fun compareTo(other: NumericalValue<U>): Int = value.compareTo(other.value)
 
-public operator fun <U: UnitsOfMeasurement> NumericalValue<U>.compareTo(other: NumericalValue<U>): Int =
+}
-    value.compareTo(other.value)
+
+public fun <U : UnitsOfMeasurement> NumericalValue(
+    number: Number,
+): NumericalValue<U> = NumericalValue(number.toDouble())
 
 public operator fun <U : UnitsOfMeasurement> NumericalValue<U>.plus(
-    other: NumericalValue<U>
+    other: NumericalValue<U>,
 ): NumericalValue<U> = NumericalValue(this.value + other.value)
 
 public operator fun <U : UnitsOfMeasurement> NumericalValue<U>.minus(
-    other: NumericalValue<U>
+    other: NumericalValue<U>,
 ): NumericalValue<U> = NumericalValue(this.value - other.value)
 
 public operator fun <U : UnitsOfMeasurement> NumericalValue<U>.times(
-    c: Number
+    c: Number,
 ): NumericalValue<U> = NumericalValue(this.value * c.toDouble())
 
 public operator fun <U : UnitsOfMeasurement> Number.times(
-    numericalValue: NumericalValue<U>
+    numericalValue: NumericalValue<U>,
 ): NumericalValue<U> = NumericalValue(numericalValue.value * toDouble())
 
 public operator fun <U : UnitsOfMeasurement> NumericalValue<U>.times(
-    c: Double
+    c: Double,
 ): NumericalValue<U> = NumericalValue(this.value * c)
 
 public operator fun <U : UnitsOfMeasurement> NumericalValue<U>.div(
-    c: Number
+    c: Number,
 ): NumericalValue<U> = NumericalValue(this.value / c.toDouble())
+
+
+private object NumericalValueMetaConverter : MetaConverter<NumericalValue<*>> {
+    override fun convert(obj: NumericalValue<*>): Meta = Meta(obj.value)
+
+    override fun readOrNull(source: Meta): NumericalValue<*>? = source.double?.let { NumericalValue<Nothing>(it) }
+}
+
+@Suppress("UNCHECKED_CAST")
+public fun <U : UnitsOfMeasurement> MetaConverter.Companion.numerical(): MetaConverter<NumericalValue<U>> =
+    NumericalValueMetaConverter as MetaConverter<NumericalValue<U>>

controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/units/UnitsOfMeasurement.kt

@@ -30,8 +30,31 @@ public data object Degrees : UnitsOfAngles
 
 /**/
 
-public interface UnitsAngularOfVelocity : UnitsOfMeasurement
+public sealed interface UnitsAngularOfVelocity : UnitsOfMeasurement
 
 public data object RadiansPerSecond : UnitsAngularOfVelocity
 
 public data object DegreesPerSecond : UnitsAngularOfVelocity
+
+/**/
+public interface UnitsOfForce: UnitsOfMeasurement
+
+public data object Newtons: UnitsOfForce
+
+/**/
+
+public interface UnitsOfTorque: UnitsOfMeasurement
+
+public data object NewtonsMeters: UnitsOfTorque
+
+/**/
+
+public interface UnitsOfMass: UnitsOfMeasurement
+
+public data object Kilograms : UnitsOfMass
+
+/**/
+
+public interface UnitsOfMomentOfInertia: UnitsOfMeasurement
+
+public data object KgM2: UnitsOfMomentOfInertia

controls-visualisation-compose/src/commonMain/kotlin/NumberTextField.kt

@@ -0,0 +1,59 @@
+package space.kscience.controls.compose
+
+import androidx.compose.foundation.layout.Row
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.KeyboardArrowLeft
+import androidx.compose.material.icons.filled.KeyboardArrowRight
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.text.TextStyle
+
+@Composable
+public fun NumberTextField(
+    value: Number,
+    onValueChange: (Number) -> Unit,
+    step: Double = 0.0,
+    formatter: (Number) -> String = { it.toString() },
+    modifier: Modifier = Modifier,
+    enabled: Boolean = true,
+    textStyle: TextStyle = LocalTextStyle.current,
+    label: @Composable (() -> Unit)? = null,
+    supportingText: @Composable (() -> Unit)? = null,
+    shape: Shape = TextFieldDefaults.shape,
+    colors: TextFieldColors = TextFieldDefaults.colors(),
+) {
+    var isError by remember { mutableStateOf(false) }
+
+    Row (verticalAlignment = Alignment.CenterVertically, modifier = modifier) {
+        step.takeIf { it > 0.0 }?.let {
+            IconButton({ onValueChange(value.toDouble() - step) }, enabled = enabled) {
+                Icon(Icons.Default.KeyboardArrowLeft, "decrease value")
+            }
+        }
+        TextField(
+            value = formatter(value),
+            onValueChange = { stringValue: String ->
+                val number = stringValue.toDoubleOrNull()
+                number?.let { onValueChange(number) }
+                isError = number == null
+            },
+            isError = isError,
+            enabled = enabled,
+            textStyle = textStyle,
+            label = label,
+            supportingText = supportingText,
+            singleLine = true,
+            shape = shape,
+            colors = colors,
+            modifier = Modifier.weight(1f)
+        )
+        step.takeIf { it > 0.0 }?.let {
+            IconButton({ onValueChange(value.toDouble() + step) }, enabled = enabled) {
+                Icon(Icons.Default.KeyboardArrowRight, "increase value")
+            }
+        }
+    }
+}

controls-visualisation-compose/src/commonMain/kotlin/TimeAxisModel.kt

@@ -19,15 +19,12 @@ public class TimeAxisModel(
         val currentRange = rangeProvider()
         val rangeLength = currentRange.endInclusive - currentRange.start
         val numTicks = floor(axisLength / minimumMajorTickSpacing).toInt()
-        val numMinorTicks = numTicks * 2
         return object : TickValues<Instant> {
             override val majorTickValues: List<Instant> = List(numTicks) {
                 currentRange.start + it.toDouble() / (numTicks - 1) * rangeLength
             }
 
-            override val minorTickValues: List<Instant> = List(numMinorTicks) {
+            override val minorTickValues: List<Instant> = emptyList()
-                currentRange.start + it.toDouble() / (numMinorTicks - 1) * rangeLength
-            }
         }
     }
 

controls-visualisation-compose/src/commonMain/kotlin/koalaPlots.kt

@@ -17,6 +17,8 @@ import space.kscience.controls.api.Device
 import space.kscience.controls.api.PropertyChangedMessage
 import space.kscience.controls.api.propertyMessageFlow
 import space.kscience.controls.constructor.DeviceState
+import space.kscience.controls.constructor.units.NumericalValue
+import space.kscience.controls.constructor.values
 import space.kscience.controls.manager.clock
 import space.kscience.controls.misc.ValueWithTime
 import space.kscience.controls.spec.DevicePropertySpec
@@ -139,7 +141,7 @@ public fun XYGraphScope<Instant, Double>.PlotDeviceProperty(
 @Composable
 public fun XYGraphScope<Instant, Double>.PlotNumberState(
     context: Context,
-    state: DeviceState<out Number>,
+    state: DeviceState<Number>,
     maxAge: Duration = defaultMaxAge,
     maxPoints: Int = defaultMaxPoints,
     minPoints: Int = defaultMinPoints,
@@ -163,6 +165,19 @@ public fun XYGraphScope<Instant, Double>.PlotNumberState(
     PlotTimeSeries(points, lineStyle)
 }
 
+@Composable
+public fun XYGraphScope<Instant, Double>.PlotNumericState(
+    context: Context,
+    state: DeviceState<NumericalValue<*>>,
+    maxAge: Duration = defaultMaxAge,
+    maxPoints: Int = defaultMaxPoints,
+    minPoints: Int = defaultMinPoints,
+    sampling: Duration = defaultSampling,
+    lineStyle: LineStyle = defaultLineStyle,
+): Unit {
+    PlotNumberState(context, state.values(), maxAge, maxPoints, minPoints, sampling, lineStyle)
+}
+
 
 private fun List<Instant>.averageTime(): Instant {
     val min = min()

demo/constructor/src/jvmMain/kotlin/PidDemo.kt

@@ -23,17 +23,27 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.datetime.Instant
 import org.jetbrains.compose.splitpane.ExperimentalSplitPaneApi
 import org.jetbrains.compose.splitpane.HorizontalSplitPane
-import space.kscience.controls.compose.PlotDeviceProperty
+import space.kscience.controls.compose.NumberTextField
-import space.kscience.controls.compose.PlotNumberState
+import space.kscience.controls.compose.PlotNumericState
 import space.kscience.controls.compose.TimeAxisModel
-import space.kscience.controls.constructor.*
+import space.kscience.controls.constructor.DeviceConstructor
-import space.kscience.controls.constructor.library.*
+import space.kscience.controls.constructor.MutableDeviceState
+import space.kscience.controls.constructor.devices.Drive
+import space.kscience.controls.constructor.devices.LimitSwitch
+import space.kscience.controls.constructor.devices.LinearDrive
+import space.kscience.controls.constructor.models.Inertia
+import space.kscience.controls.constructor.models.MutableRangeState
+import space.kscience.controls.constructor.models.PidParameters
+import space.kscience.controls.constructor.models.ScrewDrive
+import space.kscience.controls.constructor.timer
+import space.kscience.controls.constructor.units.Kilograms
+import space.kscience.controls.constructor.units.Meters
+import space.kscience.controls.constructor.units.NumericalValue
 import space.kscience.controls.manager.ClockManager
 import space.kscience.controls.manager.DeviceManager
 import space.kscience.controls.manager.clock
 import space.kscience.controls.manager.install
 import space.kscience.dataforge.context.Context
-import space.kscience.dataforge.meta.Meta
 import java.awt.Dimension
 import kotlin.math.PI
 import kotlin.math.sin
@@ -43,67 +53,79 @@ import kotlin.time.Duration.Companion.seconds
 import kotlin.time.DurationUnit
 
 
-class LinearDrive(
-    drive: Drive,
-    start: LimitSwitch,
-    end: LimitSwitch,
-    pidParameters: PidParameters,
-    meta: Meta = Meta.EMPTY,
-) : DeviceConstructor(drive.context, meta) {
-
-    val drive by device(drive)
-    val pid by device(
-        PidRegulator(
-            context = context,
-            position = drive.propertyAsState(Drive.position, 0.0),
-            pidParameters = pidParameters
-        )
-    )
-
-    private val binding = bind(pid.output, drive.stateOfForce())
-
-    val start by device(start)
-    val end by device(end)
-}
-
-/**
- * A shortcut to create a virtual [LimitSwitch] from [DoubleInRangeState]
- */
-fun LinearDrive(
-    context: Context,
-    positionState: MutableDoubleInRangeState,
-    mass: Double,
-    pidParameters: PidParameters,
-    meta: Meta = Meta.EMPTY,
-): LinearDrive = LinearDrive(
-    drive = VirtualDrive(context, mass, positionState),
-    start = LimitSwitch(context, positionState.atStart),
-    end = LimitSwitch(context, positionState.atEnd),
-    pidParameters = pidParameters,
-    meta = meta
-)
-
 class Modulator(
     context: Context,
-    target: MutableDeviceState<Double>,
+    target: MutableDeviceState<NumericalValue<Meters>>,
     var freq: Double = 0.1,
     var timeStep: Duration = 5.milliseconds,
 ) : DeviceConstructor(context) {
     private val clockStart = clock.now()
 
-    val timer = timer(10.milliseconds)
+    private val modulation = timer(10.milliseconds).onNext {
-
-    private val modulation = timer.onNext {
         val timeFromStart = clock.now() - clockStart
         val t = timeFromStart.toDouble(DurationUnit.SECONDS)
-        target.value = 5 * sin(2.0 * PI * freq * t) +
+        target.value = NumericalValue(
-                sin(2 * PI * 21 * freq * t + 0.02 * (timeFromStart / timeStep))
+            5 * sin(2.0 * PI * freq * t) +
+                    sin(2 * PI * 21 * freq * t + 0.02 * (timeFromStart / timeStep))
+        )
     }
 }
 
 
+private val inertia = NumericalValue<Kilograms>(0.1)
+
+private val leverage = NumericalValue<Meters>(0.05)
+
 private val maxAge = 10.seconds
 
+private val range = -6.0..6.0
+
+/**
+ * The whole physical model is here
+ */
+private fun createLinearDriveModel(context: Context, pidParameters: PidParameters): LinearDrive {
+
+    //create a drive model with zero starting force
+    val drive = Drive(context)
+
+    //a screw drive to converse a rotational moment into a linear one
+    val screwDrive = ScrewDrive(context, leverage)
+
+    // Create a physical position coerced in a given range
+    val position = MutableRangeState<Meters>(0.0, range)
+
+    /**
+     * Create an inertia model.
+     * The inertia uses drive force as input. Position is used as both input and output
+     *
+     * Force is the input parameter, position is output parameter
+     *
+     */
+    val inertia = Inertia.linear(
+        context = context,
+        force = screwDrive.transformForce(drive.force),
+        mass = inertia,
+        position = position
+    )
+
+    /**
+     * Create a limit switches from physical position
+     */
+    val startLimitSwitch = LimitSwitch(context, position.atStart)
+    val endLimitSwitch = LimitSwitch(context, position.atEnd)
+
+    return context.install(
+        "linearDrive",
+        LinearDrive(drive, startLimitSwitch, endLimitSwitch, position, pidParameters)
+    )
+}
+
+
+private fun createModulator(linearDrive: LinearDrive): Modulator = linearDrive.context.install(
+    "modulator",
+    Modulator(linearDrive.context, linearDrive.pid.target)
+)
+
 @OptIn(ExperimentalSplitPaneApi::class, ExperimentalKoalaPlotApi::class)
 fun main() = application {
     val context = remember {
@@ -113,27 +135,16 @@ fun main() = application {
         }
     }
 
-    val clock = remember { context.clock }
-
-
     var pidParameters by remember {
-        mutableStateOf(PidParameters(kp = 2.5, ki = 0.0, kd = -0.1, timeStep = 0.005.seconds))
+        mutableStateOf(PidParameters(kp = 900.0, ki = 20.0, kd = -50.0, timeStep = 0.005.seconds))
     }
 
-    val state = remember { MutableDoubleInRangeState(0.0, -6.0..6.0) }
+    val linearDrive: LinearDrive = remember {
-
+        createLinearDriveModel(context, pidParameters)
-    val linearDrive = remember {
-        context.install(
-            "linearDrive",
-            LinearDrive(context, state, 0.05, pidParameters)
-        )
     }
 
     val modulator = remember {
-        context.install(
+        createModulator(linearDrive)
-            "modulator",
-            Modulator(context, linearDrive.pid.target)
-        )
     }
 
     //bind pid parameters
@@ -145,6 +156,8 @@ fun main() = application {
         }.collect()
     }
 
+    val clock = remember { context.clock }
+
     Window(title = "Pid regulator simulator", onCloseRequest = ::exitApplication) {
         window.minimumSize = Dimension(800, 400)
         MaterialTheme {
@@ -153,48 +166,51 @@ fun main() = application {
                     Column(modifier = Modifier.background(color = Color.LightGray).fillMaxHeight()) {
                         Row {
                             Text("kp:", Modifier.align(Alignment.CenterVertically).width(50.dp).padding(5.dp))
-                            TextField(
+                            NumberTextField(
-                                String.format("%.2f", pidParameters.kp),
+                                value = pidParameters.kp,
-                                { pidParameters = pidParameters.copy(kp = it.toDouble()) },
+                                onValueChange = { pidParameters = pidParameters.copy(kp = it.toDouble()) },
-                                Modifier.width(100.dp),
+                                formatter = { String.format("%.2f", it.toDouble()) },
-                                enabled = false
+                                step = 1.0,
+                                modifier = Modifier.width(200.dp),
                             )
                             Slider(
                                 pidParameters.kp.toFloat(),
                                 { pidParameters = pidParameters.copy(kp = it.toDouble()) },
-                                valueRange = 0f..20f,
+                                valueRange = 0f..1000f,
                                 steps = 100
                             )
                         }
                         Row {
                             Text("ki:", Modifier.align(Alignment.CenterVertically).width(50.dp).padding(5.dp))
-                            TextField(
+                            NumberTextField(
-                                String.format("%.2f", pidParameters.ki),
+                                value = pidParameters.ki,
-                                { pidParameters = pidParameters.copy(ki = it.toDouble()) },
+                                onValueChange = { pidParameters = pidParameters.copy(ki = it.toDouble()) },
-                                Modifier.width(100.dp),
+                                formatter = { String.format("%.2f", it.toDouble()) },
-                                enabled = false
+                                step = 0.1,
+                                modifier = Modifier.width(200.dp),
                             )
 
                             Slider(
                                 pidParameters.ki.toFloat(),
                                 { pidParameters = pidParameters.copy(ki = it.toDouble()) },
-                                valueRange = -10f..10f,
+                                valueRange = -100f..100f,
                                 steps = 100
                             )
                         }
                         Row {
                             Text("kd:", Modifier.align(Alignment.CenterVertically).width(50.dp).padding(5.dp))
-                            TextField(
+                            NumberTextField(
-                                String.format("%.2f", pidParameters.kd),
+                                value = pidParameters.kd,
-                                { pidParameters = pidParameters.copy(kd = it.toDouble()) },
+                                onValueChange = { pidParameters = pidParameters.copy(kd = it.toDouble()) },
-                                Modifier.width(100.dp),
+                                formatter = { String.format("%.2f", it.toDouble()) },
-                                enabled = false
+                                step = 0.1,
+                                modifier = Modifier.width(200.dp),
                             )
 
                             Slider(
                                 pidParameters.kd.toFloat(),
                                 { pidParameters = pidParameters.copy(kd = it.toDouble()) },
-                                valueRange = -10f..10f,
+                                valueRange = -100f..100f,
                                 steps = 100
                             )
                         }
@@ -204,7 +220,7 @@ fun main() = application {
                             TextField(
                                 pidParameters.timeStep.toString(DurationUnit.MILLISECONDS),
                                 { pidParameters = pidParameters.copy(timeStep = it.toDouble().milliseconds) },
-                                Modifier.width(100.dp),
+                                Modifier.width(200.dp),
                                 enabled = false
                             )
 
@@ -233,7 +249,7 @@ fun main() = application {
                     ChartLayout {
                         XYGraph<Instant, Double>(
                             xAxisModel = remember { TimeAxisModel.recent(maxAge, clock) },
-                            yAxisModel = rememberDoubleLinearAxisModel(state.range),
+                            yAxisModel = rememberDoubleLinearAxisModel((range.start - 1.0)..(range.endInclusive + 1.0)),
                             xAxisTitle = { Text("Time in seconds relative to current") },
                             xAxisLabels = { it: Instant ->
                                 androidx.compose.material3.Text(
@@ -244,20 +260,14 @@ fun main() = application {
                             },
                             yAxisLabels = { it: Double -> Text(it.toString(2)) }
                         ) {
-                            PlotNumberState(
+                            PlotNumericState(
                                 context = context,
-                                state = state,
+                                state = linearDrive.position,
                                 maxAge = maxAge,
                                 sampling = 50.milliseconds,
                                 lineStyle = LineStyle(SolidColor(Color.Blue))
                             )
-                            PlotDeviceProperty(
+                            PlotNumericState(
-                                linearDrive.drive,
-                                Drive.position,
-                                maxAge = maxAge,
-                                sampling = 50.milliseconds,
-                            )
-                            PlotNumberState(
                                 context = context,
                                 state = linearDrive.pid.target,
                                 maxAge = maxAge,
@@ -273,10 +283,6 @@ fun main() = application {
                                     }
 
                                     1 -> {
-                                        Text("Regulator position", color = Color.Black)
-                                    }
-
-                                    2 -> {
                                         Text("Regulator target", color = Color.Red)
                                     }
                                 }