diff --git a/backend/core/api/views.py b/backend/core/api/views.py
index 756a330..1ce6325 100644
--- a/backend/core/api/views.py
+++ b/backend/core/api/views.py
@@ -183,36 +183,16 @@ def digita_gw(request):
     Digita GW endpoint implementation
     """
     identifier = request.data['DevEUI_uplink']['DevEUI']
-    try:
-        apsen = models.ApartmentSensor.objects.get(identifier=identifier)
-    except models.ApartmentSensor.DoesNotExist:
-        return Response(
-            {
-                "message": f"ApartmentSensor does not exists with given identifier {identifier}"
-            },
-            status=status.HTTP_404_NOT_FOUND,
-        )
-
+    apsen = models.ApartmentSensor.objects.get_or_create(identifier=identifier)[0]
     payload = binascii.unhexlify(request.data['DevEUI_uplink']['payload_hex'])
     decoded_payload = decode_elsys_payload(payload)
     mapping = settings.DIGITA_GW_PAYLOAD_TO_ATTRIBUTES  # type: dict
 
     for key, value in decoded_payload.items():
-        try:
-            uri = mapping[key]
-            apsenval = apsen.apartment_sensor_values.get(
-                attribute__uri=uri
-            )  # type: models.ApartmentSensorValue
-        except models.ApartmentSensorValue.DoesNotExist:
-            log.debug(
-                "ApartmentSensorValue does not exists with given URI %s (%s)", uri, key
-            )
-        except KeyError:
-            log.debug('No configured mapping to attribute for %s', key)
-            continue
+        uri = mapping.get(key, '')
+        if uri:
+            attr = models.SensorAttribute.objects.get_or_create(uri=uri, defaults={'description': key})[0]
         else:
-            apsenval.value = value
-            apsenval.save()
-            log.debug('Updated %s', apsenval)
-
+            attr = models.SensorAttribute.objects.get_or_create(description=key)[0]
+        apsen.apartment_sensor_values.create(value=value, attribute=attr)
     return Response({"message": "Updated successfully"})
diff --git a/backend/core/migrations/0017_auto_20191231_1437.py b/backend/core/migrations/0017_auto_20191231_1437.py
new file mode 100644
index 0000000..99f6281
--- /dev/null
+++ b/backend/core/migrations/0017_auto_20191231_1437.py
@@ -0,0 +1,24 @@
+# Generated by Django 2.2.8 on 2019-12-31 14:37
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0016_auto_20190130_0833'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='apartmentsensor',
+            name='apartment',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='apartment_sensors', to='core.Apartment'),
+        ),
+        migrations.AlterField(
+            model_name='apartmentsensor',
+            name='sensor',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='core.Sensor'),
+        ),
+    ]
diff --git a/backend/core/models.py b/backend/core/models.py
index a0fbf9c..1e4e25e 100644
--- a/backend/core/models.py
+++ b/backend/core/models.py
@@ -41,9 +41,8 @@ class ApartmentSensor(models.Model):
     """
 
     apartment = models.ForeignKey(
-        Apartment, related_name='apartment_sensors', on_delete=models.CASCADE
-    )
-    sensor = models.ForeignKey('Sensor', on_delete=models.DO_NOTHING)
+        Apartment, null=True, related_name='apartment_sensors', on_delete=models.SET_NULL)
+    sensor = models.ForeignKey('Sensor', null=True, on_delete=models.SET_NULL)
     identifier = models.CharField(max_length=255, unique=True)
 
     def __str__(self):
diff --git a/backend/core/tests/test_digita_gw.py b/backend/core/tests/test_digita_gw.py
index 417505c..17faa6b 100644
--- a/backend/core/tests/test_digita_gw.py
+++ b/backend/core/tests/test_digita_gw.py
@@ -11,7 +11,7 @@ def setUp(self):
         User.objects.create_user(username="nkha", password="123456")
         self.client.login(username="nkha", password="123456")
 
-    def test_invalid_gw_data(self):
+    def test_new_sensor_gw_data(self):
         # No sensor
         data = {
             "DevEUI_uplink": {
@@ -57,7 +57,8 @@ def test_invalid_gw_data(self):
         }
 
         response = self.client.post(self.url, data, format='json')
-        self.assertEqual(404, response.status_code)
+        self.assertEqual(200, response.status_code)
+        self.assertTrue(ApartmentSensor.objects.filter(identifier="A81758FFFE030CF6").exists())
 
     def test_valid_gw_data(self):
         sensor = Sensor.objects.create(name="T-800")