diff --git a/app/src/main/java/eu/ztsh/garmin/Garmin.kt b/app/src/main/java/eu/ztsh/garmin/Garmin.kt
index dc70096..aaf8f0c 100644
--- a/app/src/main/java/eu/ztsh/garmin/Garmin.kt
+++ b/app/src/main/java/eu/ztsh/garmin/Garmin.kt
@@ -5,6 +5,7 @@ import android.bluetooth.BluetoothAdapter
 import android.bluetooth.BluetoothDevice
 import android.bluetooth.BluetoothSocket
 import android.util.Log
+import com.mapbox.navigation.core.trip.session.LocationMatcherResult
 import com.mapbox.navigation.tripdata.maneuver.model.Maneuver
 import com.mapbox.navigation.tripdata.progress.model.TripProgressUpdateValue
 import eu.ztsh.garmin.data.Arrows
@@ -27,10 +28,10 @@ class Garmin(
     private lateinit var connection: ConnectThread
     private lateinit var maneuvers: ManeuverProcessingThread
     private lateinit var trips: TripProgressProcessingThread
+    private lateinit var locations: LocationMatcherProcessingThread
     private val cache = DataCache()
 
-    private val maneuversPool = Executors.newFixedThreadPool(4)
-    private val tripPool = Executors.newFixedThreadPool(4)
+    private val processingPool = Executors.newFixedThreadPool(8)
 
     fun start() {
         connection = ConnectThread()
@@ -41,6 +42,9 @@ class Garmin(
 
         trips = TripProgressProcessingThread()
         trips.start()
+
+        locations = LocationMatcherProcessingThread()
+        locations.start()
     }
 
     fun close() {
@@ -52,16 +56,38 @@ class Garmin(
         trips.interrupt()
         trips.join(0)
 
-        maneuversPool.shutdown()
-        tripPool.shutdown()
+        locations.interrupt()
+        locations.join(0)
+
+        processingPool.shutdown()
     }
 
     fun process(maneuver: Maneuver) {
-        maneuversPool.submit{maneuvers.enqueue(maneuver)}
+        processingPool.submit{maneuvers.enqueue(maneuver)}
     }
 
     fun process(tripProgressUpdateValue: TripProgressUpdateValue) {
-        maneuversPool.submit{trips.enqueue(tripProgressUpdateValue)}
+        processingPool.submit{trips.enqueue(tripProgressUpdateValue)}
+    }
+
+    fun process(locationMatcherResult: LocationMatcherResult) {
+        processingPool.submit{locations.enqueue(locationMatcherResult)}
+    }
+
+    private inner class LocationMatcherProcessingThread: ProcessingThread<LocationMatcherResult>() {
+
+        override fun mapAndSend(maybeItem: LocationMatcherResult?): LocationMatcherResult? {
+            if (maybeItem != null && cache.hasChanged(maybeItem)) {
+                send(GarminMapper.map(MapboxMapper.asSpeed(maybeItem)))
+                return maybeItem
+            }
+            return null
+        }
+
+        override fun updateCache(item: LocationMatcherResult) {
+            cache.update(item)
+        }
+
     }
 
     private inner class TripProgressProcessingThread : ProcessingThread<TripProgressUpdateValue>() {
diff --git a/app/src/main/java/eu/ztsh/garmin/data/DataCache.kt b/app/src/main/java/eu/ztsh/garmin/data/DataCache.kt
index 61bedfb..3e61688 100644
--- a/app/src/main/java/eu/ztsh/garmin/data/DataCache.kt
+++ b/app/src/main/java/eu/ztsh/garmin/data/DataCache.kt
@@ -42,7 +42,9 @@ class DataCache {
 
     // location
     fun hasChanged(locationMatcherResult: LocationMatcherResult): Boolean {
-        return locationCache == null || locationCache!! != locationMatcherResult
+        return locationCache.let { it == null
+                || it.enhancedLocation.speed != locationMatcherResult.enhancedLocation.speed
+                || it.speedLimitInfo.speed != locationMatcherResult.speedLimitInfo.speed }
     }
 
     fun update(locationMatcherResult: LocationMatcherResult) {
diff --git a/app/src/main/java/eu/ztsh/garmin/mapbox/LocationObserver.kt b/app/src/main/java/eu/ztsh/garmin/mapbox/LocationObserver.kt
index 998eebe..8dfefde 100644
--- a/app/src/main/java/eu/ztsh/garmin/mapbox/LocationObserver.kt
+++ b/app/src/main/java/eu/ztsh/garmin/mapbox/LocationObserver.kt
@@ -4,6 +4,7 @@ import com.mapbox.common.location.Location
 import com.mapbox.navigation.core.trip.session.LocationMatcherResult
 import com.mapbox.navigation.core.trip.session.LocationObserver
 import com.mapbox.navigation.ui.maps.camera.transition.NavigationCameraTransitionOptions
+import eu.ztsh.garmin.Garmin
 
 class LocationObserver(private val mapControl: MapControl) : LocationObserver {
 
@@ -31,6 +32,8 @@ class LocationObserver(private val mapControl: MapControl) : LocationObserver {
         mapControl.viewportDataSource.onLocationChanged(enhancedLocation)
         mapControl.viewportDataSource.evaluate()
 
+        Garmin.instance.process(locationMatcherResult)
+
         // if this is the first location update the activity has received,
         // it's best to immediately move the camera to the current user location
         if (!firstLocationUpdateReceived) {