diff --git a/app/src/androidTest/java/pl/rmakowiecki/smartalarmcore/ExampleInstrumentedTest.java b/app/src/androidTest/java/pl/rmakowiecki/smartalarmcore/ExampleInstrumentedTest.java
deleted file mode 100644
index 8d5763c..0000000
--- a/app/src/androidTest/java/pl/rmakowiecki/smartalarmcore/ExampleInstrumentedTest.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package pl.rmakowiecki.smartalarmcore;
-
-import android.content.Context;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import static org.junit.Assert.*;
-
-/**
- * Instrumentation test, which will execute on an Android device.
- *
- * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
- */
-@RunWith(AndroidJUnit4.class)
-public class ExampleInstrumentedTest {
-    @Test
-    public void useAppContext() throws Exception {
-        // Context of the app under test.
-        Context appContext = InstrumentationRegistry.getTargetContext();
-
-        assertEquals("pl.rmakowiecki.smartalarmcore", appContext.getPackageName());
-    }
-}
diff --git a/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmActivity.kt b/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmActivity.kt
index eb1ca6a..0347806 100644
--- a/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmActivity.kt
+++ b/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmActivity.kt
@@ -8,6 +8,7 @@ import android.util.Log
 import pl.rmakowiecki.smartalarmcore.peripheral.beam.BeamBreakDetectorPeriphery
 import pl.rmakowiecki.smartalarmcore.peripheral.camera.CameraPeripheryContract
 import pl.rmakowiecki.smartalarmcore.peripheral.motion.MotionSensorPeriphery
+import pl.rmakowiecki.smartalarmcore.peripheral.soundalarm.SoundAlarmPeriphery
 import pl.rmakowiecki.smartalarmcore.remote.AlarmBackendContract
 import pl.rmakowiecki.smartalarmcore.setup.UsbSetupProviderContract
 
@@ -17,7 +18,6 @@ class AlarmActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-//        printWifiNetworkStatus() test
         alarmController = initSystemController()
     }
 
@@ -25,6 +25,7 @@ class AlarmActivity : AppCompatActivity() {
             BeamBreakDetectorPeriphery(),
             MotionSensorPeriphery(),
             CameraPeripheryContract.create(this),
+            SoundAlarmPeriphery(),
             AlarmBackendContract.create(this),
             UsbSetupProviderContract.create(this)
     )
diff --git a/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmController.kt b/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmController.kt
index 32c8d8e..3829244 100644
--- a/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmController.kt
+++ b/app/src/main/java/pl/rmakowiecki/smartalarmcore/AlarmController.kt
@@ -7,6 +7,7 @@ import pl.rmakowiecki.smartalarmcore.extensions.applyIoSchedulers
 import pl.rmakowiecki.smartalarmcore.extensions.logD
 import pl.rmakowiecki.smartalarmcore.peripheral.AlarmTriggerPeripheralDevice
 import pl.rmakowiecki.smartalarmcore.peripheral.camera.CameraPeripheryContract
+import pl.rmakowiecki.smartalarmcore.peripheral.soundalarm.SoundAlarmPeriphery
 import pl.rmakowiecki.smartalarmcore.remote.AlarmBackendContract
 import pl.rmakowiecki.smartalarmcore.remote.models.AlarmTriggerReason
 import pl.rmakowiecki.smartalarmcore.remote.models.SecurityIncident
@@ -16,6 +17,7 @@ class AlarmController(
         private val beamBreakDetector: AlarmTriggerPeripheralDevice,
         private val motionSensor: AlarmTriggerPeripheralDevice,
         private val camera: CameraPeripheryContract,
+        private val soundAlarmPeriphery: SoundAlarmPeriphery,
         private val backendInteractor: AlarmBackendContract,
         private val usbSetupProvider: UsbSetupProviderContract
 ) {
@@ -71,7 +73,8 @@ class AlarmController(
                                 updateAlarmTriggerState(it)
                                 if (it == TRIGGERED) {
                                     reportAlarmIncident(AlarmTriggerReason.BEAM_BREAK_DETECTOR)
-                                }
+                                    soundAlarmPeriphery.startSiren()
+                                } else soundAlarmPeriphery.stopSiren()
                             }
                     )
         }
@@ -84,10 +87,12 @@ class AlarmController(
                     .applyIoSchedulers()
                     .subscribeBy(
                             onNext = {
-                                updateAlarmTriggerState(it)
+                                //                                updateAlarmTriggerState(it)
                                 if (it == TRIGGERED) {
-                                    reportAlarmIncident(AlarmTriggerReason.MOTION_SENSOR)
-                                }
+//                                    reportAlarmIncident(AlarmTriggerReason.MOTION_SENSOR)
+                                    logD("motion sensor triggered")
+                                    soundAlarmPeriphery.startSiren()
+                                } else soundAlarmPeriphery.stopSiren()
                             }
                     )
         }
diff --git a/app/src/main/java/pl/rmakowiecki/smartalarmcore/peripheral/soundalarm/SoundAlarmPeriphery.kt b/app/src/main/java/pl/rmakowiecki/smartalarmcore/peripheral/soundalarm/SoundAlarmPeriphery.kt
new file mode 100644
index 0000000..f6e276e
--- /dev/null
+++ b/app/src/main/java/pl/rmakowiecki/smartalarmcore/peripheral/soundalarm/SoundAlarmPeriphery.kt
@@ -0,0 +1,38 @@
+package pl.rmakowiecki.smartalarmcore.peripheral.soundalarm
+
+import com.google.android.things.pio.Gpio
+import com.google.android.things.pio.PeripheralManagerService
+import pl.rmakowiecki.smartalarmcore.extensions.logE
+
+private const val PIN_NAME = "BCM21"
+
+class SoundAlarmPeriphery {
+
+    private lateinit var alarmSirenGpio: Gpio
+
+    init {
+        initAndRegisterGpioCallback()
+    }
+
+    private fun initAndRegisterGpioCallback() {
+        val service = PeripheralManagerService()
+        try {
+            alarmSirenGpio = service.openGpio(PIN_NAME)
+            alarmSirenGpio.apply {
+                setDirection(Gpio.DIRECTION_OUT_INITIALLY_LOW)
+            }
+
+        } catch (ex: Exception) {
+            ex.printStackTrace()
+            logE("GPIO exception")
+        }
+    }
+
+    fun startSiren() {
+        alarmSirenGpio.value = true
+    }
+
+    fun stopSiren() {
+        alarmSirenGpio.value = false
+    }
+}
diff --git a/app/src/main/java/pl/rmakowiecki/smartalarmcore/remote/AlarmBackendInteractor.kt b/app/src/main/java/pl/rmakowiecki/smartalarmcore/remote/AlarmBackendInteractor.kt
index 68650cb..6ec5e4e 100644
--- a/app/src/main/java/pl/rmakowiecki/smartalarmcore/remote/AlarmBackendInteractor.kt
+++ b/app/src/main/java/pl/rmakowiecki/smartalarmcore/remote/AlarmBackendInteractor.kt
@@ -133,12 +133,22 @@ class AlarmBackendInteractor(private val activity: AlarmActivity) : AlarmBackend
     }
 
     override fun uploadIncidentPhoto(photoBytes: ByteArray, uniqueIncidentId: String, photoNumber: Int): Single<Boolean> = Single.create { emitter ->
+        val photoFileName = "$uniqueIncidentId#$photoNumber.jpg"
+
         storageNode.child(CORE_DEVICE_DIRECTORY)
                 .child(IMAGES_DIRECTORY)
                 .child(getCurrentBackendUser()?.uid ?: "non_assignable_incidents")
-                .child("$uniqueIncidentId#$photoNumber.jpg")
+                .child(photoFileName)
                 .putBytes(photoBytes)
-                .addOnCompleteListener { emitter.onSuccess(it.isSuccessful) }
+                .addOnCompleteListener {
+                    databaseNode
+                            .child(getCurrentBackendUser()?.uid)
+                            .child("incidents")
+                            .child(uniqueIncidentId)
+                            .child("photos")
+                            .child("$photoNumber")
+                            .setValue(it.isSuccessful)
+                }
     }
 }