diff --git a/.idea/misc.xml b/.idea/misc.xml
index dfd2c79..b6ea2b1 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" project-jdk-name="JDK" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="JDK" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/app/src/main/java/de/asaril/bletail/BleConnectionHandler.kt b/app/src/main/java/de/asaril/bletail/BleConnectionHandler.kt
new file mode 100644
index 0000000..a413f58
--- /dev/null
+++ b/app/src/main/java/de/asaril/bletail/BleConnectionHandler.kt
@@ -0,0 +1,89 @@
+package de.asaril.bletail
+
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothManager
+import android.bluetooth.le.ScanCallback
+import android.bluetooth.le.ScanResult
+import android.content.Context
+import android.content.Intent
+import android.util.Log
+import no.nordicsemi.android.ble.callback.SuccessCallback
+
+class BleConnectionHandler(main: MainActivity) {
+
+    private var ble: UartManager? = null
+    private val activity: MainActivity = main
+
+    var connected = false
+        private set
+
+    private fun ByteArray.toHexString() = joinToString("") { "%02x".format(it) }
+
+
+    fun connect(callback: ((Boolean) -> Unit)?) {
+
+        ble = UartManager(activity)
+        ble!!.setGattCallbacks(DefaultUartManagerCallbacks())
+
+        val bluetoothManager: BluetoothManager =
+            activity.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
+        val bluetoothAdapter: BluetoothAdapter = bluetoothManager.adapter
+
+        if (!bluetoothAdapter.isEnabled) {
+            val enableIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
+            val requestEnableBt = 1
+            activity.startActivityForResult(enableIntent, requestEnableBt)
+        }
+
+        bluetoothAdapter.bluetoothLeScanner.startScan(object : ScanCallback() {
+            override fun onScanResult(callbackType: Int, result: ScanResult) {
+                super.onScanResult(callbackType, result)
+                Log.i("BLEtail", "Remote device name: " + result.device.name)
+
+                if (result.device.name == "Bluefruit52") {
+                    bluetoothAdapter.bluetoothLeScanner.stopScan(this)
+                    ble!!.connect(result.device)
+                        .retry(3, 100)
+                        .useAutoConnect(true)
+                        .done {
+                            connected = true
+                            if (callback != null) {
+                                callback(connected)
+                            }
+                        }
+                        .fail { _: BluetoothDevice, _: Int ->
+                            connected = false
+                            if (callback != null) {
+                                callback(connected)
+                            }
+                        }
+                        .enqueue()
+                }
+            }
+        })
+
+    }
+
+    fun disconnect(callback: ((Boolean) -> Unit)?) {
+        ble!!.disconnect()
+            .done {
+                connected = false
+                if (callback != null) {
+                    callback(connected)
+                }
+            }
+            .enqueue()
+    }
+
+    fun sendToBleUart(msgRaw: ByteArray) {
+        if (connected) {
+            val arr: ByteArray = CobsUtils.encode(msgRaw)
+            Log.i("BLEtail", "tx:" + arr.toHexString())
+            ble?.send(arr)
+        } else {
+            Log.w("BLEtail", "tx failed (not connected):" + msgRaw.toHexString())
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/de/asaril/bletail/MainActivity.kt b/app/src/main/java/de/asaril/bletail/MainActivity.kt
index 584ca74..2ac7afc 100644
--- a/app/src/main/java/de/asaril/bletail/MainActivity.kt
+++ b/app/src/main/java/de/asaril/bletail/MainActivity.kt
@@ -1,18 +1,9 @@
 package de.asaril.bletail
 
-import CobsUtils
-import android.bluetooth.BluetoothAdapter
-import android.bluetooth.BluetoothManager
-import android.bluetooth.le.ScanCallback
-import android.bluetooth.le.ScanResult
-import android.content.Context
-import android.content.Intent
 import android.graphics.Color
 import android.os.Bundle
 import android.text.InputType
-import android.util.Log
 import android.view.Menu
-import android.view.MenuItem
 import android.widget.EditText
 import android.widget.LinearLayout
 import android.widget.SeekBar
@@ -23,56 +14,46 @@ import kotlinx.android.synthetic.main.activity_main.*
 import org.json.JSONArray
 import org.json.JSONObject
 import java.io.File
-
+import android.view.MenuItem
+import android.view.View
 
 class MainActivity : AppCompatActivity() {
 
     private val LED_COUNT: Int = 40
 
-    private var ble: UartManager? = null
+    private var ble: BleConnectionHandler? = null
+    private var wasConnected = false
 
     private var segments: MutableList<SegmentCardView>? = null
+    private var paused = false
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
         setSupportActionBar(toolbar)
 
+        ble = BleConnectionHandler(this)
+
         segments = MutableList<SegmentCardView>(5, init = {
             SegmentCardView(this, it, 0, LED_COUNT - 1, Fx.Mode.THEATER_CHASE_RAINBOW, Color(), Color(), Color(), 0x0800, false)
         })
         for (s in segments!!) {
-            s.sendCallback = this::sendToBleUart
+            s.sendCallback = { bytes: ByteArray -> ble!!.sendToBleUart(bytes) }
         }
 
-
-        ble = UartManager(this)
-        ble!!.setGattCallbacks(DefaultUartManagerCallbacks())
-
-        val bluetoothManager: BluetoothManager =
-            getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
-        val bluetoothAdapter: BluetoothAdapter = bluetoothManager.adapter
-
-        if (!bluetoothAdapter.isEnabled) {
-            val enableIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
-            val requestEnableBt = 1
-            startActivityForResult(enableIntent, requestEnableBt)
-        }
-
-        bluetoothAdapter.bluetoothLeScanner.startScan(object : ScanCallback() {
-            override fun onScanResult(callbackType: Int, result: ScanResult) {
-                super.onScanResult(callbackType, result)
-                Log.i("BLEtail", "Remote device name: " + result.device.name)
-
-                if (result.device.name == "Bluefruit52") {
-                    bluetoothAdapter.bluetoothLeScanner.stopScan(this)
-                    ble!!.connect(result.device)
-                        .retry(3, 100)
-                        .useAutoConnect(true)
-                        .enqueue()
+        ble!!.connect { connected: Boolean ->
+            if (connected) {
+                val storedState = File(getExternalFilesDir(null)!!, "_stored.json")
+                val loaded = storedState.exists() and loadFile(storedState)
+                if (!loaded) {
+                    val defaultFile = File(getExternalFilesDir(null)!!, "default.json")
+                    if (defaultFile.exists()) {
+                        loadFile(defaultFile)
+                    }
                 }
             }
-        })
+            updateConnection(connected)
+        }
 
         brightness!!.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener {
             override fun onProgressChanged(var1: SeekBar, var2: Int, var3: Boolean) {
@@ -90,15 +71,49 @@ class MainActivity : AppCompatActivity() {
 
     }
 
+    override fun onResume() {
+        if (wasConnected) {
+            ble?.connect { c -> updateConnection(c) }
+        }
+        super.onResume()
+    }
+
+    override fun onPause() {
+        saveFile("_stored")
+        super.onPause()
+    }
+
+    override fun onStop() {
+        wasConnected = (ble?.connected) ?: false
+        ble?.disconnect { c -> updateConnection(c) }
+        super.onStop()
+    }
+
     override fun onDestroy() {
         segments = null
-        ble!!.disconnect()
+        ble!!.disconnect { c -> updateConnection(c) }
+        val storedState = File(getExternalFilesDir(null)!!, "_stored.json")
+        if (storedState.exists()) {
+            storedState.deleteOnExit()
+        }
         super.onDestroy()
     }
 
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
         // Inflate the menu; this adds items to the action bar if it is present.
         menuInflater.inflate(R.menu.main_menu, menu)
+
+        val connected = (ble != null) and (ble!!.connected)
+        menu.findItem(R.id.action_connection).apply {
+            if (connected) {
+                icon = getDrawable(R.drawable.ic_bluetooth_connected_black_24dp)
+                title = getString(R.string.disconnect)
+            } else {
+                icon = getDrawable(R.drawable.ic_bluetooth_disabled_black_24dp)
+                title = getString(R.string.connect)
+            }
+        }
+
         return true
     }
 
@@ -107,28 +122,30 @@ class MainActivity : AppCompatActivity() {
         val m = Fx.setNumSegments_msg.newBuilder()
         m.numSegments = count
         r.setNumSegments = m.build()
-        sendToBleUart(r.build().toByteArray())
+        if (ble != null) {
+            ble!!.sendToBleUart(r.build().toByteArray())
 
-        val segLength: Int = LED_COUNT / count
-        val segmentListLayout = findViewById<LinearLayout>(R.id.segmentList)
+            val segLength: Int = LED_COUNT / count
+            val segmentListLayout = findViewById<LinearLayout>(R.id.segmentList)
 
-        for (i in 0 until count) {
-            segments!![i].start = segLength * i
-            segments!![i].end = if (i == count - 1) {
-                LED_COUNT - 1
-            } else {
-                (segLength * (i + 1) - 1)
+            for (i in 0 until count) {
+                segments!![i].start = segLength * i
+                segments!![i].end = if (i == count - 1) {
+                    LED_COUNT - 1
+                } else {
+                    (segLength * (i + 1) - 1)
+                }
+                segments!![i].sendSetSegment()
             }
-            segments!![i].sendSetSegment()
-        }
 
-        while (segmentListLayout.childCount > count) {
-            val ind = segmentListLayout.childCount - 1
-            segmentListLayout.removeViewAt(ind)
-        }
-        while (segmentListLayout.childCount < count) {
-            val ind = segmentListLayout.childCount
-            segmentListLayout.addView(segments!![ind], ind)
+            while (segmentListLayout.childCount > count) {
+                val ind = segmentListLayout.childCount - 1
+                segmentListLayout.removeViewAt(ind)
+            }
+            while (segmentListLayout.childCount < count) {
+                val ind = segmentListLayout.childCount
+                segmentListLayout.addView(segments!![ind], ind)
+            }
         }
     }
 
@@ -141,8 +158,9 @@ class MainActivity : AppCompatActivity() {
                 val r: Fx.Root.Builder = Fx.Root.newBuilder()
                 r.halt = Fx.halt_msg.newBuilder().build()
                 val msgRaw = r.build().toByteArray()
-                sendToBleUart(msgRaw)
-                ble!!.disconnect()
+                ble?.sendToBleUart(msgRaw)
+                ble?.disconnect(null)
+                finish()
             }
         }
         builder.setNegativeButton("Cancel") { dialog, _ -> dialog.cancel() }
@@ -154,7 +172,7 @@ class MainActivity : AppCompatActivity() {
         val m = Fx.setBrightness_msg.newBuilder()
         m.brightness = value
         r.setBrightness = m.build()
-        sendToBleUart(r.build().toByteArray())
+        ble?.sendToBleUart(r.build().toByteArray())
     }
 
     fun segCountClick(item: MenuItem) {
@@ -169,13 +187,6 @@ class MainActivity : AppCompatActivity() {
         )
     }
 
-    fun sendToBleUart(msgRaw: ByteArray) {
-        val arr: ByteArray = CobsUtils.encode(msgRaw)
-        fun ByteArray.toHexString() = joinToString("") { "%02x".format(it) }
-        Log.i("BLEtail", "tx:" + arr.toHexString())
-        ble?.send(arr)
-    }
-
 
     fun serialize(): JSONObject {
         val j = JSONObject()
@@ -189,21 +200,32 @@ class MainActivity : AppCompatActivity() {
         return j
     }
 
-    fun deserialize(j: JSONObject) {
+    fun deserialize(j: JSONObject): Boolean {
         brightness.progress = j.getInt("brightness")
         val jsegs = j.getJSONArray("segments")
-        updateSegmentCards(jsegs.length())
-        for (i in 0 until jsegs.length()) {
+        val segNum = jsegs.length()
+        if (segNum < 1) {
+            return false
+        }
+        updateSegmentCards(segNum)
+        for (i in 0 until segNum) {
             val jseg = jsegs[i] as JSONObject
             val idx = jseg.getInt("index")
             assert(idx < segments!!.size)
             segments!![idx].deserialize(jseg)
         }
+        return true
     }
 
-    private fun loadFile(file: File) {
+    private fun loadFile(file: File): Boolean {
         val j = JSONObject(file.readText())
-        deserialize(j)
+        val loaded = deserialize(j)
+        if ((!loaded) and (file.name == "_stored.json")) {
+            // remove broken stored state
+            file.delete()
+            return false
+        }
+        return loaded
     }
 
     private fun saveFile(filename: String) {
@@ -240,5 +262,99 @@ class MainActivity : AppCompatActivity() {
         builder.show()
     }
 
+    fun pauseClick(item: MenuItem) {
+        if ((ble != null) && (ble!!.connected)) {
+            this.paused = !this.paused
+            sendPause(item)
+        }
+
+    }
+
+    private fun sendPause(item: MenuItem) {
+        val r = Fx.Root.newBuilder()
+        if (paused) {
+            val m = Fx.pause_msg.newBuilder()
+            r.pause = m.build()
+            item.icon = getDrawable(android.R.drawable.ic_media_play)
+            item.title = getString(R.string.resume)
+        } else {
+            val m = Fx.resume_msg.newBuilder()
+            r.resume = m.build()
+            item.icon = getDrawable(android.R.drawable.ic_media_pause)
+            item.title = getString(R.string.pause)
+        }
+        ble?.sendToBleUart(r.build().toByteArray())
+    }
+
+    fun updateConnection(connected: Boolean) {
+        (findViewById<View?>(R.id.action_connection) as MenuItem?)?.apply {
+            if (connected) {
+                icon = getDrawable(R.drawable.ic_bluetooth_connected_black_24dp)
+                title = getString(R.string.disconnect)
+            } else {
+                icon = getDrawable(R.drawable.ic_bluetooth_disabled_black_24dp)
+                title = getString(R.string.connect)
+            }
+        }
+    }
+
+    fun connectionClick(item: MenuItem) {
+        val callback = { connected: Boolean ->
+            item.apply {
+                if (connected) {
+                    icon = getDrawable(R.drawable.ic_bluetooth_connected_black_24dp)
+                    title = getString(R.string.disconnect)
+                } else {
+                    icon = getDrawable(R.drawable.ic_bluetooth_disabled_black_24dp)
+                    title = getString(R.string.connect)
+                }
+            }
+            Unit
+        }
+
+        if (ble != null) {
+            if (ble!!.connected) {
+                ble!!.disconnect(callback)
+            } else {
+                ble!!.connect(callback)
+            }
+        }
+    }
+
+    fun stopClick(item: MenuItem) {
+        if ((ble != null) && (ble!!.connected)) {
+            paused = true
+            sendPause(item)
+
+            val r = Fx.Root.newBuilder()
+            val m = Fx.strip_off_msg.newBuilder()
+            r.stripOff = m.build()
+            ble?.sendToBleUart(r.build().toByteArray())
+        }
+
+        val storedState = File(getExternalFilesDir(null)!!, "_stored.json")
+        if (storedState.exists()) {
+            storedState.deleteOnExit()
+        }
+    }
+
+    fun syncClick(item: MenuItem) {
+        if ((ble != null) && (ble!!.connected) && (segments != null)) {
+            var r = Fx.Root.newBuilder()
+            val m = Fx.stop_msg.newBuilder()
+            r.stop = m.build()
+            ble?.sendToBleUart(r.build().toByteArray())
+
+            for (i in 0 until segments!!.size) {
+                segments!![i].speed = segments!![0].speed
+                segments!![i].updateView()
+            }
+
+            r = Fx.Root.newBuilder()
+            val m2 = Fx.start_msg.newBuilder()
+            r.start = m2.build()
+            ble?.sendToBleUart(r.build().toByteArray())
+        }
+    }
 
 }
diff --git a/app/src/main/java/de/asaril/bletail/SegmentCardView.kt b/app/src/main/java/de/asaril/bletail/SegmentCardView.kt
index 059d620..309b707 100644
--- a/app/src/main/java/de/asaril/bletail/SegmentCardView.kt
+++ b/app/src/main/java/de/asaril/bletail/SegmentCardView.kt
@@ -266,17 +266,22 @@ class SegmentCardView : CardView {
         assert(this.index == j.getInt("index"))
         this.start = j.getInt("start")
         this.end = j.getInt("end")
-        this.mode = Fx.Mode.forNumber(j.getInt("mode"))
+
         val jcolors = j.getJSONArray("colors")
         this.colors[0] = Color.valueOf(jcolors[0] as Int)
         this.colors[1] = Color.valueOf(jcolors[1] as Int)
         this.colors[2] = Color.valueOf(jcolors[2] as Int)
         this.speed = j.getInt("speed")
+
         this.reverse = j.getBoolean("reverse")
+
+        // set mode last as this will trigger setSegment
+        this.mode = Fx.Mode.forNumber(j.getInt("mode"))
         updateView()
+        sendSetSegment()
     }
 
-    private fun updateView() {
+    fun updateView() {
         viewCol0!!.setColorFilter(colors[0].toArgb())
         viewCol1!!.setColorFilter(colors[1].toArgb())
         viewCol2!!.setColorFilter(colors[2].toArgb())
diff --git a/app/src/main/res/drawable/ic_bluetooth_connected_black_24dp.xml b/app/src/main/res/drawable/ic_bluetooth_connected_black_24dp.xml
new file mode 100644
index 0000000..c81c3a3
--- /dev/null
+++ b/app/src/main/res/drawable/ic_bluetooth_connected_black_24dp.xml
@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M7,12l-2,-2 -2,2 2,2 2,-2zM17.71,7.71L12,2h-1v7.59L6.41,5 5,6.41 10.59,12 5,17.59 6.41,19 11,14.41L11,22h1l5.71,-5.71 -4.3,-4.29 4.3,-4.29zM13,5.83l1.88,1.88L13,9.59L13,5.83zM14.88,16.29L13,18.17v-3.76l1.88,1.88zM19,10l-2,2 2,2 2,-2 -2,-2z"/>
+</vector>
diff --git a/app/src/main/res/drawable/ic_bluetooth_disabled_black_24dp.xml b/app/src/main/res/drawable/ic_bluetooth_disabled_black_24dp.xml
new file mode 100644
index 0000000..1f753a2
--- /dev/null
+++ b/app/src/main/res/drawable/ic_bluetooth_disabled_black_24dp.xml
@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M13,5.83l1.88,1.88 -1.6,1.6 1.41,1.41 3.02,-3.02L12,2h-1v5.03l2,2v-3.2zM5.41,4L4,5.41 10.59,12 5,17.59 6.41,19 11,14.41V22h1l4.29,-4.29 2.3,2.29L20,18.59 5.41,4zM13,18.17v-3.76l1.88,1.88L13,18.17z"/>
+</vector>
diff --git a/app/src/main/res/menu/main_menu.xml b/app/src/main/res/menu/main_menu.xml
index 29eacc4..d31c881 100644
--- a/app/src/main/res/menu/main_menu.xml
+++ b/app/src/main/res/menu/main_menu.xml
@@ -9,14 +9,28 @@
         android:iconTint="@android:color/secondary_text_dark"
         android:title="@string/load"
         android:onClick="loadBtnClick"
-        app:showAsAction="ifRoom" />
+        app:showAsAction="always" />
     <item
         android:id="@+id/saveBtn"
         android:title="@string/save"
         android:icon="@android:drawable/ic_menu_save"
         android:iconTint="@android:color/primary_text_dark"
         android:onClick="saveBtnClick"
-        app:showAsAction="ifRoom"/>
+        app:showAsAction="always"/>
+
+    <item
+        android:id="@+id/action_pause"
+        android:icon="@android:drawable/ic_media_pause"
+        android:onClick="pauseClick"
+        android:title="@string/pause"
+        app:showAsAction="always" />
+
+    <item
+        android:id="@+id/action_connection"
+        android:icon="@drawable/ic_bluetooth_disabled_black_24dp"
+        android:onClick="connectionClick"
+        android:title="@string/connect"
+        app:showAsAction="ifRoom" />
 
     <item
         android:id="@+id/segCountMenu"
@@ -48,8 +62,20 @@
         </menu>
     </item>
     <item
-        android:id="@+id/action_halt"
+        android:id="@+id/action_sync"
+        android:icon="@android:drawable/ic_popup_sync"
+        android:onClick="syncClick"
+        android:title="@string/action_sync"
+        app:showAsAction="collapseActionView" />
+    <item
+        android:id="@+id/action_stop"
         android:icon="@android:drawable/ic_lock_power_off"
+        android:onClick="stopClick"
+        android:title="@string/action_stop"
+        app:showAsAction="collapseActionView" />
+    <item
+        android:id="@+id/action_halt"
+        android:icon="@android:drawable/ic_delete"
         android:onClick="powerOffClick"
         android:title="@string/action_halt"
         app:showAsAction="collapseActionView" />
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index caef947..dfd58c2 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,6 +1,6 @@
 <resources>
     <string name="app_name">BLEtail</string>
-    <string name="action_halt">Halt</string>
+    <string name="action_halt">Shutdown</string>
     <string name="action_settings">Settings</string>
     <string name="seg3">3</string>
     <string name="seg5">5</string>
@@ -15,4 +15,10 @@
     <string name="brightness">Brightness</string>
     <string name="load">Load</string>
     <string name="save">Save</string>
+    <string name="connect">Connect</string>
+    <string name="disconnect">Disconnect</string>
+    <string name="pause">Pause</string>
+    <string name="resume">Resume</string>
+    <string name="action_stop">Stop (Off)</string>
+    <string name="action_sync">Sync</string>
 </resources>