o Reading values from the soil sensor.

o Rewrote the database schema to match the new device+sensors model.
o Storing samples in the database.
o To be able to reuse BT callbacks, added a way to always to directly to the next step instead of waiting for an event.

13 files changed, 563 insertions, 170 deletions

diff --git a/app/src/main/java/io/trygvis/android/Consumer.java b/app/src/main/java/io/trygvis/android/Consumer.java
new file mode 100644
index 0000000..bf8c5e5
--- /dev/null
+++ b/app/src/main/java/io/trygvis/android/Consumer.java
@@ -0,0 +1,5 @@
+package io.trygvis.android;
+
+public interface Consumer<T> {
+    void accept(T t);
+}
diff --git a/app/src/main/java/io/trygvis/android/bt/BtCallback.java b/app/src/main/java/io/trygvis/android/bt/BtCallback.java
index 8dab149..71f7d56 100644
--- a/app/src/main/java/io/trygvis/android/bt/BtCallback.java
+++ b/app/src/main/java/io/trygvis/android/bt/BtCallback.java
@@ -4,16 +4,18 @@ import android.bluetooth.BluetoothGatt;
 import android.bluetooth.BluetoothGattCharacteristic;
 import android.bluetooth.BluetoothGattDescriptor;
 
-import static io.trygvis.android.bt.BtPromise.*;
+import static io.trygvis.android.bt.BtPromise.PromiseResult;
 
 public class BtCallback {
+    public final boolean stopOnFailure;
     public final String name;
 
-    public BtCallback(String name) {
+    public BtCallback(boolean stopOnFailure, String name) {
+        this.stopOnFailure = stopOnFailure;
         this.name = name;
     }
 
-    public PromiseResult onConnectionStateChange(BluetoothGatt gatt, int newState) {
+    public PromiseResult onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
         throw new NotOverriddenException();
     }
 
@@ -49,6 +51,10 @@ public class BtCallback {
         throw new NotOverriddenException();
     }
 
+    public PromiseResult onDirect(Object value) {
+        throw new NotOverriddenException();
+    }
+
     public void onFailure() {
         throw new NotOverriddenException();
     }
diff --git a/app/src/main/java/io/trygvis/android/bt/BtDevice.java b/app/src/main/java/io/trygvis/android/bt/BtDevice.java
index 1c7666e..d8dfefc 100644
--- a/app/src/main/java/io/trygvis/android/bt/BtDevice.java
+++ b/app/src/main/java/io/trygvis/android/bt/BtDevice.java
@@ -3,6 +3,7 @@ package io.trygvis.android.bt;
 import android.bluetooth.BluetoothDevice;
 import android.bluetooth.BluetoothGatt;
 import android.bluetooth.BluetoothGattCallback;
+import android.database.sqlite.SQLiteDatabase;
 import android.util.Log;
 
 import java.util.Date;
@@ -21,23 +22,25 @@ public class BtDevice<A extends BtDevice.BtDeviceWrapper<A>> {
     private final boolean seenBefore;
     private final Date firstSeen;
     private Date lastSeen;
+    private boolean connected;
 
     public static interface BtDeviceWrapper<A extends BtDevice.BtDeviceWrapper<A>> {
         BtDevice<A> getBtDevice();
     }
 
-    BtDevice(DefaultBtService btService, BluetoothDevice bluetoothDevice,
+    BtDevice(DefaultBtService btService, BluetoothDevice bluetoothDevice, SQLiteDatabase db,
              BtService.BtDbIntegration<A> btDbIntegration, long id, Integer rssi,
              BtScanResult scanResult, boolean seenBefore, Date firstSeen, Date lastSeen) {
         this.btService = btService;
         this.bluetoothDevice = bluetoothDevice;
-        this.tag = btDbIntegration.createTag(this);
         this.id = id;
         this.rssi = rssi;
         this.scanResult = scanResult;
         this.seenBefore = seenBefore;
         this.firstSeen = firstSeen;
         this.lastSeen = lastSeen;
+
+        this.tag = btDbIntegration.createTag(db, this);
     }
 
     public long getId() {
@@ -60,6 +63,10 @@ public class BtDevice<A extends BtDevice.BtDeviceWrapper<A>> {
         return rssi;
     }
 
+    public BtScanResult getScanResult() {
+        return scanResult;
+    }
+
     public boolean isSeenBefore() {
         return seenBefore;
     }
@@ -78,8 +85,15 @@ public class BtDevice<A extends BtDevice.BtDeviceWrapper<A>> {
 
     public synchronized boolean connect(BtPromise executor) {
         Log.i(TAG, "connect(), address=" + bluetoothDevice.getAddress());
-        BluetoothGattCallback callback = executor.asCallback();
-        gatt = bluetoothDevice.connectGatt(btService, false, callback);
+        BluetoothGattCallback callback = executor.asCallback(bluetoothDevice.getAddress());
+        gatt = bluetoothDevice.connectGatt(btService, false, new WrappingBluetoothGattCallback(callback) {
+            @Override
+            public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+                BtDevice.this.connected = newState == BluetoothGatt.STATE_CONNECTED;
+
+                super.onConnectionStateChange(gatt, status, newState);
+            }
+        });
         return true;
     }
 
@@ -90,8 +104,8 @@ public class BtDevice<A extends BtDevice.BtDeviceWrapper<A>> {
         }
     }
 
-    public BtScanResult getScanResult() {
-        return scanResult;
+    public boolean connected() {
+        return connected;
     }
 
     @Override
diff --git a/app/src/main/java/io/trygvis/android/bt/BtPromise.java b/app/src/main/java/io/trygvis/android/bt/BtPromise.java
index 55b6315..6af62c0 100644
--- a/app/src/main/java/io/trygvis/android/bt/BtPromise.java
+++ b/app/src/main/java/io/trygvis/android/bt/BtPromise.java
@@ -10,9 +10,11 @@ import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.ListIterator;
 import java.util.Queue;
 
 import io.trygvis.android.F2;
+import io.trygvis.android.F3;
 import io.trygvis.android.Function;
 
 import static io.trygvis.android.bt.BtPromise.EventType.onCharacteristicChanged;
@@ -21,6 +23,7 @@ import static io.trygvis.android.bt.BtPromise.EventType.onCharacteristicWrite;
 import static io.trygvis.android.bt.BtPromise.EventType.onConnectionStateChange;
 import static io.trygvis.android.bt.BtPromise.EventType.onDescriptorRead;
 import static io.trygvis.android.bt.BtPromise.EventType.onDescriptorWrite;
+import static io.trygvis.android.bt.BtPromise.EventType.onDirect;
 import static io.trygvis.android.bt.BtPromise.EventType.onFailure;
 import static io.trygvis.android.bt.BtPromise.EventType.onFinally;
 import static io.trygvis.android.bt.BtPromise.EventType.onReliableWriteCompleted;
@@ -28,20 +31,48 @@ import static io.trygvis.android.bt.BtPromise.EventType.onServicesDiscovered;
 
 public class BtPromise {
     private final static String TAG = BtPromise.class.getSimpleName();
-    private final Queue<BtCallback> actionQ = new ArrayDeque<>();
+    private final List<BtCallback> actionQ = new ArrayList<>();
     private final Queue<BtCallback> failureQ = new ArrayDeque<>();
     private final Queue<BtCallback> finallyQ = new ArrayDeque<>();
 
-    public static final PromiseResult continueDownChain = new Continue();
-    public static final PromiseResult doneWithChain = new Done();
+    private static final PromiseResult waitForNextEvent = new WaitForNextEvent();
+    private static final PromiseResult stop = new Stop();
 
-    public abstract static class PromiseResult {
+    private Boolean stopOnFailure;
+
+    public static class PromiseResult {
+        private PromiseResult() {
+        }
+
+        public static PromiseResult waitForNextEvent() {
+            return waitForNextEvent;
+        }
+
+        public static PromiseResult continueDirectly(Object value) {
+            return new ContinueDirectly(value);
+        }
+
+        public static PromiseResult stop() {
+            return stop;
+        }
+
+        public static PromiseResult detour(BtPromise promise) {
+            return new Detour(promise);
+        }
     }
 
-    private static class Continue extends PromiseResult {
+    private static class WaitForNextEvent extends PromiseResult {
     }
 
-    private static class Done extends PromiseResult {
+    private static class ContinueDirectly extends PromiseResult {
+        private final Object value;
+
+        private ContinueDirectly(Object value) {
+            this.value = value;
+        }
+    }
+
+    private static class Stop extends PromiseResult {
     }
 
     private static class Detour extends PromiseResult {
@@ -52,18 +83,32 @@ public class BtPromise {
         }
     }
 
-    public synchronized BtPromise onConnectionStateChange(F2<BluetoothGatt, Integer, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onConnectionStateChange") {
+    private boolean stopOnFailure() {
+        if(stopOnFailure != null) {
+            boolean b = stopOnFailure;
+            stopOnFailure = null;
+            return b;
+        }
+        return false;
+    }
+
+    public BtPromise ignoreFailureForNext() {
+        stopOnFailure = true;
+        return this;
+    }
+    
+    public synchronized BtPromise onConnectionStateChange(F3<BluetoothGatt, Integer, Integer, PromiseResult> callback) {
+        actionQ.add(new BtCallback(stopOnFailure(), "onConnectionStateChange") {
             @Override
-            public PromiseResult onConnectionStateChange(BluetoothGatt gatt, int newState) {
-                return callback.apply(gatt, newState);
+            public PromiseResult onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+                return callback.apply(gatt, status,newState);
             }
         });
         return this;
     }
 
     public synchronized BtPromise onServicesDiscovered(Function<BluetoothGatt, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onServicesDiscovered") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onServicesDiscovered") {
             @Override
             public PromiseResult onServicesDiscovered(BluetoothGatt gatt) {
                 return callback.apply(gatt);
@@ -73,7 +118,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onCharacteristicRead(F2<BluetoothGatt, BluetoothGattCharacteristic, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onCharacteristicRead") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onCharacteristicRead") {
             @Override
             public PromiseResult onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
                 return callback.apply(gatt, characteristic);
@@ -83,7 +128,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onCharacteristicWrite(F2<BluetoothGatt, BluetoothGattCharacteristic, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onCharacteristicWrite") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onCharacteristicWrite") {
             @Override
             public PromiseResult onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
                 return callback.apply(gatt, characteristic);
@@ -93,7 +138,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onCharacteristicChanged(F2<BluetoothGatt, BluetoothGattCharacteristic, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onCharacteristicChanged") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onCharacteristicChanged") {
             @Override
             public PromiseResult onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
                 return callback.apply(gatt, characteristic);
@@ -103,7 +148,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onDescriptorRead(F2<BluetoothGatt, BluetoothGattDescriptor, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onDescriptorRead") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onDescriptorRead") {
             @Override
             public PromiseResult onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
                 return callback.apply(gatt, descriptor);
@@ -113,7 +158,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onDescriptorWrite(F2<BluetoothGatt, BluetoothGattDescriptor, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onDescriptorWrite") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onDescriptorWrite") {
             @Override
             public PromiseResult onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
                 return callback.apply(gatt, descriptor);
@@ -123,7 +168,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onReliableWriteCompleted(Function<BluetoothGatt, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onReliableWriteCompleted") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onReliableWriteCompleted") {
             @Override
             public PromiseResult onReliableWriteCompleted(BluetoothGatt gatt) {
                 return callback.apply(gatt);
@@ -133,7 +178,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onReadRemoteRssi(F2<BluetoothGatt, Integer, PromiseResult> callback) {
-        actionQ.add(new BtCallback("onReadRemoteRssi") {
+        actionQ.add(new BtCallback(stopOnFailure(), "onReadRemoteRssi") {
             @Override
             public PromiseResult onReadRemoteRssi(BluetoothGatt gatt, int rssi) {
                 return callback.apply(gatt, rssi);
@@ -142,8 +187,18 @@ public class BtPromise {
         return this;
     }
 
+    public synchronized BtPromise onDirect(Function<Object, PromiseResult> callback) {
+        actionQ.add(new BtCallback(stopOnFailure(), "onDirect") {
+            @Override
+            public PromiseResult onDirect(Object value) {
+                return callback.apply(value);
+            }
+        });
+        return this;
+    }
+
     public synchronized BtPromise onFailure(Runnable callback) {
-        failureQ.add(new BtCallback("onFailure") {
+        failureQ.add(new BtCallback(stopOnFailure(), "onFailure") {
             @Override
             public void onFailure() {
                 callback.run();
@@ -153,7 +208,7 @@ public class BtPromise {
     }
 
     public synchronized BtPromise onFinally(Runnable callback) {
-        finallyQ.add(new BtCallback("finally") {
+        finallyQ.add(new BtCallback(stopOnFailure(), "finally") {
             @Override
             public void onFinally() {
                 callback.run();
@@ -180,12 +235,8 @@ public class BtPromise {
         return s.toString();
     }
 
-    BtBluetoothGattCallback asCallback() {
-        return new BtBluetoothGattCallback(actionQ, failureQ, finallyQ);
-    }
-
-    public PromiseResult toDetour() {
-        return new Detour(this);
+    BtBluetoothGattCallback asCallback(String address) {
+        return new BtBluetoothGattCallback(address, actionQ, failureQ, finallyQ);
     }
 
     enum EventType {
@@ -200,16 +251,18 @@ public class BtPromise {
 
         onReadRemoteRssi,
 
+        onDirect,
         onFailure,
         onFinally,
     }
 
     private static PromiseResult callCallback(EventType key, BluetoothGatt gatt,
                                               BluetoothGattCharacteristic characteristic,
-                                              BluetoothGattDescriptor descriptor, int newState, BtCallback btCallback) {
+                                              BluetoothGattDescriptor descriptor, int status, int newState,
+                                              BtCallback btCallback, Object value) {
         switch (key) {
             case onConnectionStateChange:
-                return btCallback.onConnectionStateChange(gatt, newState);
+                return btCallback.onConnectionStateChange(gatt, status, newState);
             case onServicesDiscovered:
                 return btCallback.onServicesDiscovered(gatt);
             case onCharacteristicRead:
@@ -225,6 +278,8 @@ public class BtPromise {
             case onReliableWriteCompleted:
                 return btCallback.onReliableWriteCompleted(gatt);
 
+            case onDirect:
+                return btCallback.onDirect(value);
             case onFailure:
                 btCallback.onFailure();
                 return null;
@@ -239,23 +294,27 @@ public class BtPromise {
 
     static class BtBluetoothGattCallback extends BluetoothGattCallback {
 
-        private ArrayDeque<BtCallback> actionQ;
+        private final String address;
+        private List<BtCallback> actionQ;
+        private ListIterator<BtCallback> it;
         private ArrayDeque<BtCallback> failureQ;
         ArrayDeque<BtCallback> finallyQ;
-//        private ArrayDeque<BtCallback> initialActionQ;
         private List<String> events = new ArrayList<>();
 
-        private BtBluetoothGattCallback(Queue<BtCallback> actionQ, Queue<BtCallback> failureQ, Queue<BtCallback> finallyQ) {
-            this.actionQ = new ArrayDeque<>(actionQ);
+        private BtBluetoothGattCallback(String address, List<BtCallback> actionQ, Queue<BtCallback> failureQ, Queue<BtCallback> finallyQ) {
+            this.address = address;
+            this.actionQ = new ArrayList<>(actionQ);
             this.failureQ = new ArrayDeque<>(failureQ);
             this.finallyQ = new ArrayDeque<>(finallyQ);
+            this.it = actionQ.listIterator();
         }
 
-        void onEvent(EventType key, String values, BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, BluetoothGattDescriptor descriptor, int status, int newState) {
+        void onEvent(EventType key, String values, BluetoothGatt gatt, BluetoothGattCharacteristic characteristic,
+                     BluetoothGattDescriptor descriptor, int status, int newState, Object value) {
             boolean success = status == BluetoothGatt.GATT_SUCCESS;
             events.add(key + "(" + values + "), success=" + success);
 
-            Log.i(TAG, key + "(" + values + "), success=" + success);
+            Log.i(TAG, "event: " + key + "(" + values + "), success=" + success);
 
             if (!success) {
                 doFailure();
@@ -264,31 +323,33 @@ public class BtPromise {
 
             BtCallback btCallback;
             synchronized (this) {
-                if (actionQ.isEmpty()) {
+                if (!it.hasNext()) {
                     Log.d(TAG, "All Bluetooth actions are done");
 
                     doFinally();
                     return;
                 }
 
+                btCallback = it.next();
+                Log.i(TAG, "Executing bt action: " + btCallback.name);
                 try {
                     Thread.sleep(1000);
                 } catch (InterruptedException e) {
                     // ignore
                 }
-                btCallback = actionQ.remove();
-                Log.i(TAG, "Executing bt action: " + btCallback.name);
             }
 
             try {
-                PromiseResult result = callCallback(key, gatt, characteristic, descriptor, newState, btCallback);
+                PromiseResult result = callCallback(key, gatt, characteristic, descriptor, status, newState, btCallback,
+                        value);
 
-                if (result instanceof Done) {
-                    Log.i(TAG, "The chain is done.");
+                if (result instanceof Stop) {
+                    Log.i(TAG, "The chain want to stop.");
                     doFinally();
                 } else if (result instanceof Detour) {
                     Log.i(TAG, "Adding detour");
                     BtPromise promise = ((Detour) result).promise;
+                    events.add("detour " + promise.actionQ.size());
                     if (!promise.failureQ.isEmpty()) {
                         Log.i(TAG, "Ignoring " + promise.failureQ.size() + " items from the failure Q");
                     }
@@ -296,12 +357,19 @@ public class BtPromise {
                         Log.i(TAG, "Ignoring " + promise.finallyQ.size() + " items from the finally Q");
                     }
 
-                    for (BtCallback callback : promise.actionQ) {
-                        actionQ.addFirst(callback);
+                    synchronized (this) {
+                        for (BtCallback cb : promise.actionQ) {
+                            it.add(cb);
+                        }
                     }
+                } else if (result instanceof ContinueDirectly) {
+                    value = ((ContinueDirectly) result).value;
+                    onEvent(onDirect, "value=" + value, null, null, null, BluetoothGatt.GATT_SUCCESS, 0,
+                            value);
+                    return;
                 }
 
-                if (actionQ.isEmpty()) {
+                if (!it.hasNext()) {
                     Log.i(TAG, "The queue is empty");
                 }
             } catch (NotOverriddenException e) {
@@ -313,14 +381,15 @@ public class BtPromise {
         private void doFailure() {
             StringBuilder msg = new StringBuilder();
 
+            msg.append("Address: ").append(address).append("\n");
             msg.append("Expected events: \n");
             for (BtCallback cb : actionQ) {
-                msg.append("  ").append(cb.name).append("\n");
+                msg.append("-  ").append(cb.name).append("\n");
             }
 
             msg.append("Actual events: \n");
             for (String event : events) {
-                msg.append("  ").append(event).append("\n");
+                msg.append("-  ").append(event).append("\n");
             }
 
             Log.w(TAG, msg.toString());
@@ -329,7 +398,7 @@ public class BtPromise {
 
             for (BtCallback callback = failureQ.poll(); callback != null; callback = failureQ.poll()) {
                 try {
-                    callCallback(onFailure, null, null, null, 0, callback);
+                    callCallback(onFailure, null, null, null, 0, 0, callback, null);
                 } catch (NotOverriddenException e) {
                     return;
                 }
@@ -345,7 +414,7 @@ public class BtPromise {
 
             for (BtCallback callback = finallyQ.poll(); callback != null; callback = finallyQ.poll()) {
                 try {
-                    callCallback(onFinally, null, null, null, 0, callback);
+                    callCallback(onFinally, null, null, null, 0, 0, callback, null);
                 } catch (NotOverriddenException e) {
                     return;
                 }
@@ -358,42 +427,42 @@ public class BtPromise {
 
         @Override
         public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
-            onEvent(onConnectionStateChange, "status=" + status + ", newState=" + newState, gatt, null, null, status, newState);
+            onEvent(onConnectionStateChange, "status=" + status + ", newState=" + newState, gatt, null, null, status, newState, null);
         }
 
         @Override
         public void onServicesDiscovered(BluetoothGatt gatt, int status) {
-            onEvent(onServicesDiscovered, "status=" + status, gatt, null, null, status, 9);
+            onEvent(onServicesDiscovered, "status=" + status, gatt, null, null, status, 9, null);
         }
 
         @Override
         public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
-            onEvent(onCharacteristicRead, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0);
+            onEvent(onCharacteristicRead, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0, null);
         }
 
         @Override
         public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
-            onEvent(onCharacteristicWrite, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0);
+            onEvent(onCharacteristicWrite, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0, null);
         }
 
         @Override
         public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
-            onEvent(onCharacteristicChanged, "characteristic=" + characteristic.getUuid(), gatt, characteristic, null, BluetoothGatt.GATT_SUCCESS, 0);
+            onEvent(onCharacteristicChanged, "characteristic=" + characteristic.getUuid(), gatt, characteristic, null, BluetoothGatt.GATT_SUCCESS, 0, null);
         }
 
         @Override
         public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
-            onEvent(onDescriptorRead, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0);
+            onEvent(onDescriptorRead, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0, null);
         }
 
         @Override
         public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
-            onEvent(onDescriptorWrite, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0);
+            onEvent(onDescriptorWrite, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0, null);
         }
 
         @Override
         public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
-            onEvent(onReliableWriteCompleted, "status=" + status, gatt, null, null, status, 0);
+            onEvent(onReliableWriteCompleted, "status=" + status, gatt, null, null, status, 0, null);
         }
 
         @Override
diff --git a/app/src/main/java/io/trygvis/android/bt/BtService.java b/app/src/main/java/io/trygvis/android/bt/BtService.java
index fb11027..ff2c68c 100644
--- a/app/src/main/java/io/trygvis/android/bt/BtService.java
+++ b/app/src/main/java/io/trygvis/android/bt/BtService.java
@@ -33,7 +33,7 @@ public interface BtService<A extends BtDevice.BtDeviceWrapper<A>> {
     <T> T runTx(Function<SQLiteDatabase, T> action);
 
     public static interface BtDbIntegration<A extends BtDevice.BtDeviceWrapper<A>> {
-        A createTag(BtDevice<A> a);
+        A createTag(SQLiteDatabase db, BtDevice<A> a);
     }
 
     public static class BtServiceListenerBroadcastReceiver extends BroadcastReceiver {
diff --git a/app/src/main/java/io/trygvis/android/bt/DefaultBtService.java b/app/src/main/java/io/trygvis/android/bt/DefaultBtService.java
index 80a195a..cc7d484 100644
--- a/app/src/main/java/io/trygvis/android/bt/DefaultBtService.java
+++ b/app/src/main/java/io/trygvis/android/bt/DefaultBtService.java
@@ -289,7 +289,7 @@ public class DefaultBtService<A extends BtDevice.BtDeviceWrapper<A>> extends Ser
 
             Log.i(TAG, "New device: " + address + ", seenBefore=" + seenBefore);
             cursor.close();
-            return new BtDevice<>(this, bluetoothDevice, btDbIntegration, id, rssi, scanResult,
+            return new BtDevice<>(this, bluetoothDevice, db, btDbIntegration, id, rssi, scanResult,
                     seenBefore, firstSeen, lastSeen);
         });
 
diff --git a/app/src/main/java/io/trygvis/android/bt/WrappingBluetoothGattCallback.java b/app/src/main/java/io/trygvis/android/bt/WrappingBluetoothGattCallback.java
new file mode 100644
index 0000000..8d790d1
--- /dev/null
+++ b/app/src/main/java/io/trygvis/android/bt/WrappingBluetoothGattCallback.java
@@ -0,0 +1,60 @@
+package io.trygvis.android.bt;
+
+import android.bluetooth.BluetoothGatt;
+import android.bluetooth.BluetoothGattCallback;
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.bluetooth.BluetoothGattDescriptor;
+
+class WrappingBluetoothGattCallback extends BluetoothGattCallback {
+
+    private final BluetoothGattCallback wrapped;
+
+    public WrappingBluetoothGattCallback(BluetoothGattCallback wrapped) {
+        this.wrapped = wrapped;
+    }
+
+    @Override
+    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+        wrapped.onConnectionStateChange(gatt, status, newState);
+    }
+
+    @Override
+    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
+        wrapped.onServicesDiscovered(gatt, status);
+    }
+
+    @Override
+    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
+        wrapped.onCharacteristicRead(gatt, characteristic, status);
+    }
+
+    @Override
+    public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
+        wrapped.onCharacteristicWrite(gatt, characteristic, status);
+    }
+
+    @Override
+    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+        wrapped.onCharacteristicChanged(gatt, characteristic);
+    }
+
+    @Override
+    public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
+        wrapped.onDescriptorRead(gatt, descriptor, status);
+    }
+
+    @Override
+    public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
+        wrapped.onDescriptorWrite(gatt, descriptor, status);
+    }
+
+    @Override
+    public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
+        wrapped.onReliableWriteCompleted(gatt, status);
+    }
+
+    @Override
+    public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
+        wrapped.onReadRemoteRssi(gatt, rssi, status);
+    }
+}
diff --git a/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java b/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java
index a2723d5..3ff6e66 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java
@@ -9,12 +9,17 @@ import android.content.ComponentName;
 import android.content.ContentValues;
 import android.content.Intent;
 import android.content.ServiceConnection;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
 import android.os.IBinder;
 import android.util.Log;
 
 import java.util.ArrayList;
 import java.util.Comparator;
+import java.util.Date;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
 
@@ -25,15 +30,24 @@ import io.trygvis.android.bt.BtService;
 import io.trygvis.android.bt.DefaultBtService;
 import io.trygvis.bluetooth.TrygvisIoUuids;
 
-import static io.trygvis.android.bt.BtPromise.continueDownChain;
-import static io.trygvis.android.bt.BtPromise.doneWithChain;
+import static io.trygvis.android.bt.BtPromise.PromiseResult.continueDirectly;
+import static io.trygvis.android.bt.BtPromise.PromiseResult.detour;
+import static io.trygvis.android.bt.BtPromise.PromiseResult.stop;
+import static io.trygvis.android.bt.BtPromise.PromiseResult.waitForNextEvent;
 import static io.trygvis.android.bt.BtService.BtServiceListenerBroadcastReceiver;
+import static io.trygvis.bluetooth.TrygvisIoUuids.CLIENT_CHARACTERISTIC_CONFIG;
 import static io.trygvis.soilmoisture.SmDevice.GetSensorCountRes;
+import static io.trygvis.soilmoisture.SmDevice.GetValueRes;
 import static io.trygvis.soilmoisture.SmDevice.SmCmdCode.GET_SENSOR_COUNT;
+import static io.trygvis.soilmoisture.SmDevice.SmCmdCode.GET_VALUE;
+import static io.trygvis.soilmoisture.SmDevice.createGetSensorCountReq;
+import static io.trygvis.soilmoisture.SmDevice.createGetValueReq;
+import static io.trygvis.soilmoisture.SmDevice.parseResponse;
+import static java.lang.String.valueOf;
+import static java.lang.System.currentTimeMillis;
 
 public class DefaultSoilMoistureService extends Service implements SoilMoistureService {
     private final static String TAG = DefaultSoilMoistureService.class.getSimpleName();
-    private final static int DEFAULT_WARNING_LEVEL = 750;
 
     private final IBinder binder = new LocalBinder<>(this);
 
@@ -58,7 +72,7 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
             @Override
             public void onServiceConnected(ComponentName componentName, IBinder service) {
                 btService = ((LocalBinder<BtService<SmDevice>>) service).getService();
-                boolean ok = btService.initialize(DefaultSoilMoistureService.this::onNewDevice);
+                boolean ok = btService.initialize(DefaultSoilMoistureService.this::createTag);
 
                 sendBroadcast(createReady(ok));
             }
@@ -98,28 +112,16 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
             BtDevice<SmDevice> btDevice = btService.getDevice(address);
             SmDevice smDevice = btDevice.getTag();
 
+            sendBroadcast(createNewDevice(address));
+
             if (!smDevice.isProbed()) {
                 Log.i(TAG, "Probing " + address + ", name=" + btDevice.getName());
                 BtPromise executor = new BtPromise().
-                        onConnectionStateChange((gatt, newState) -> {
-                            //noinspection SimplifiableIfStatement
-                            if (newState == BluetoothGatt.STATE_CONNECTED) {
-                                Log.i(TAG, "Connected to " + address + ", getting services");
-                                return gatt.discoverServices() ? continueDownChain : doneWithChain;
-                            } else {
-                                Log.i(TAG, "Disconnected from " + address + ", trying again");
-
-                                return new BtPromise().onConnectionStateChange((gatt2, newState2) -> {
-                                    if (newState2 == BluetoothGatt.STATE_CONNECTED) {
-                                        Log.i(TAG, "Connected to " + address + ", getting services");
-                                        return continueDownChain;
-                                    }
-
-                                    Log.i(TAG, "Could still not connect to " + address + ", failing.");
-
-                                    return doneWithChain;
-                                }).toDetour();
-                            }
+                        ignoreFailureForNext().
+                        onConnectionStateChange(DefaultSoilMoistureService::defaultConnectCallback).
+                        onDirect(v -> {
+                            BluetoothGatt gatt = (BluetoothGatt) v;
+                            return gatt.discoverServices() ? waitForNextEvent() : stop();
                         }).
                         onServicesDiscovered(gatt -> {
                             Log.i(TAG, "Services discovered");
@@ -127,38 +129,37 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
                             BluetoothGattService service = gatt.getService(TrygvisIoUuids.Services.SOIL_MOISTURE_SERVICE);
 
                             if (service == null) {
-                                return doneWithChain;
+                                return stop();
                             }
 
                             BluetoothGattCharacteristic soilMoisture = service.getCharacteristic(TrygvisIoUuids.Characteristics.SOIL_MOISTURE);
 
                             if (soilMoisture == null) {
-                                return doneWithChain;
+                                return stop();
                             }
 
                             BluetoothGattDescriptor ccg = soilMoisture.getDescriptor(TrygvisIoUuids.CLIENT_CHARACTERISTIC_CONFIG);
                             ccg.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
                             gatt.setCharacteristicNotification(soilMoisture, true);
 
-                            return gatt.writeDescriptor(ccg) ? continueDownChain : doneWithChain;
+                            return gatt.writeDescriptor(ccg) ? waitForNextEvent() : stop();
                         }).
                         onDescriptorWrite((gatt, descriptor) -> {
                             Log.i(TAG, "Notifications enabled, getting sensor count");
                             BluetoothGattCharacteristic c = descriptor.getCharacteristic();
-                            c.setValue(SmDevice.createGetSensorCountReq());
-                            return gatt.writeCharacteristic(c) ? continueDownChain : doneWithChain;
+                            c.setValue(createGetSensorCountReq());
+                            return gatt.writeCharacteristic(c) ? waitForNextEvent() : stop();
                         }).
-                        onCharacteristicWrite((gatt, characteristic) -> continueDownChain).
+                        onCharacteristicWrite((gatt, characteristic) -> waitForNextEvent()).
                         onCharacteristicChanged((gatt, characteristic) -> {
-                            GetSensorCountRes getSensorCountRes = SmDevice.parseResponse(characteristic.getValue(),
+                            GetSensorCountRes getSensorCountRes = parseResponse(characteristic.getValue(),
                                     GET_SENSOR_COUNT, GetSensorCountRes.class);
 
                             Log.i(TAG, "The device has " + getSensorCountRes.count + " sensors.");
 
-                            smDevice.setIsUseful(true);
-                            smDevice.setSensorCount(getSensorCountRes.count);
+                            markDeviceAsUseful(smDevice, getSensorCountRes.count);
 
-                            return doneWithChain;
+                            return stop();
                         }).
                         onFinally(() -> {
                             btDevice.disconnect();
@@ -167,28 +168,69 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
                                 smDevice.setIsUseful(false);
                             }
 
-                            btService.runTx(db -> {
-                                if (!btDevice.isSeenBefore() && smDevice.isUseful()) {
-                                    for (SmSensor soilMonitor : smDevice.getSensors()) {
-                                        ContentValues values = new ContentValues();
-                                        values.put("bt_device", btDevice.getId());
-                                        values.put("warning_level", DEFAULT_WARNING_LEVEL);
-                                        db.insert("soil_monitor", null, values);
-                                    }
-                                }
-
-                                return null;
-                            });
-                            sendBroadcast(createNewDevice(address));
                         });
 
                 btDevice.connect(executor);
-            } else {
-                sendBroadcast(createNewDevice(address));
             }
         }
     };
 
+    private void markDeviceAsUseful(SmDevice device, int sensorCount) {
+        btService.runTx(db -> {
+            device.setIsUseful(true);
+
+            // Find all already registered sensors and register the rest
+            Map<Integer, Long> indexes = new HashMap<>();
+            Cursor cursor = db.query(Tables.T_SM_SENSOR, new String[]{Tables.C_ID, Tables.C_INDEX},
+                    Tables.C_SM_DEVICE + "=?", new String[]{valueOf(device.id)}, null, null, null);
+            while (cursor.moveToNext()) {
+                indexes.put(cursor.getInt(1), cursor.getLong(0));
+            }
+
+            ContentValues values = new ContentValues();
+            values.put(Tables.C_USEFUL, true);
+            db.update(Tables.T_SM_DEVICE, values, "id=?", new String[]{valueOf(device.id)});
+
+            for (int i = 0; i < sensorCount; i++) {
+                Long id = indexes.get(i);
+
+                if (id == null) {
+                    values = new ContentValues();
+                    values.put(Tables.C_SM_DEVICE, device.id);
+                    values.put(Tables.C_INDEX, i);
+                    id = db.insert(Tables.T_SM_SENSOR, null, values);
+                }
+
+                device.addSensor(new SmSensor(device, id, (byte) i));
+            }
+
+            return null;
+        });
+    }
+
+    public static BtPromise.PromiseResult defaultConnectCallback(BluetoothGatt gatt, int status, Integer newState) {
+        Log.i(TAG, "defaultConnectCallback: status=" + status + ", newState=" + newState);
+        String address = gatt.getDevice().getAddress();
+        //noinspection SimplifiableIfStatement
+        if (status == BluetoothGatt.GATT_SUCCESS && newState == BluetoothGatt.STATE_CONNECTED) {
+            Log.i(TAG, "Connected to " + address);
+            return continueDirectly(gatt);
+        } else {
+            Log.i(TAG, "Disconnected from " + address + ", trying again");
+
+            return detour(new BtPromise().onConnectionStateChange((gatt2, status2, newState2) -> {
+                if (newState2 == BluetoothGatt.STATE_CONNECTED) {
+                    Log.i(TAG, "Connected to " + address);
+                    return continueDirectly(gatt);
+                }
+
+                Log.i(TAG, "Could still not connect to " + address + ", failing.");
+
+                return stop();
+            }));
+        }
+    }
+
     // -----------------------------------------------------------------------
     // SmDevicesManager Implementation
     // -----------------------------------------------------------------------
@@ -223,13 +265,82 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
     }
 
     // -----------------------------------------------------------------------
-    // Event creation and dispatching
+    //
     // -----------------------------------------------------------------------
 
-    private SmDevice onNewDevice(BtDevice<SmDevice> btDevice) {
-        return new SmDevice(btDevice);
+    private SmDevice createTag(SQLiteDatabase db, BtDevice<SmDevice> btDevice) {
+        Cursor cursor = db.query(Tables.T_SM_DEVICE, new String[]{Tables.C_ID}, Tables.C_BT_DEVICE + "=?",
+                new String[]{valueOf(btDevice.getId())}, null, null, null);
+
+        long id;
+        if (cursor.moveToNext()) {
+            id = cursor.getLong(0);
+        } else {
+            ContentValues values = new ContentValues();
+            values.put(Tables.C_BT_DEVICE, btDevice.getId());
+            id = db.insert(Tables.T_SM_DEVICE, null, values);
+        }
+
+        return new SmDevice(this, btDevice, id);
+    }
+
+    void handleNewSensorValueReady(SmSensor sensor, int value) {
+        long timestamp = currentTimeMillis();
+        btService.runTx(db -> {
+            ContentValues values = new ContentValues();
+            values.put(Tables.C_SM_SENSOR, sensor.getId());
+            values.put(Tables.C_TIMESTAMP, timestamp);
+            values.put(Tables.C_VALUE, value);
+            return db.insert(Tables.T_SOIL_SAMPLE, null, values);
+        });
+
+        sensor.updateLastValue(new Date(timestamp), value);
+        sendBroadcast(createNewSample(sensor));
+    }
+
+    void readCurrentValue(SmSensor sensor) {
+        BtPromise promise = new BtPromise().
+                onConnectionStateChange(DefaultSoilMoistureService::defaultConnectCallback).
+                onDirect(v -> {
+                    BluetoothGatt gatt = (BluetoothGatt) v;
+                    return gatt.discoverServices() ? waitForNextEvent() : stop();
+                }).
+                onServicesDiscovered(gatt -> {
+                    BluetoothGattService service = gatt.getService(TrygvisIoUuids.Services.SOIL_MOISTURE_SERVICE);
+                    BluetoothGattCharacteristic soilMoisture = service.getCharacteristic(TrygvisIoUuids.Characteristics.SOIL_MOISTURE);
+
+                    BluetoothGattDescriptor ccg = soilMoisture.getDescriptor(CLIENT_CHARACTERISTIC_CONFIG);
+                    ccg.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
+                    gatt.setCharacteristicNotification(soilMoisture, true);
+
+                    return gatt.writeDescriptor(ccg) ? waitForNextEvent() : stop();
+                }).
+                onDescriptorWrite((gatt, descriptor) -> {
+                    BluetoothGattCharacteristic c = descriptor.getCharacteristic();
+                    c.setValue(createGetValueReq((byte) sensor.getIndex()));
+                    return gatt.writeCharacteristic(c) ? waitForNextEvent() : stop();
+                }).
+                onCharacteristicWrite((gatt, characteristic) -> waitForNextEvent()).
+                onCharacteristicChanged((gatt, characteristic) -> {
+                    GetValueRes getSensorCountRes = parseResponse(characteristic.getValue(),
+                            GET_VALUE, GetValueRes.class);
+
+                    handleNewSensorValueReady(sensor, getSensorCountRes.value);
+
+                    gatt.disconnect();
+
+                    return stop();
+                }).
+                onFinally(() -> {
+                });
+
+        sensor.getDevice().getBtDevice().connect(promise);
     }
 
+    // -----------------------------------------------------------------------
+    // Event creation and dispatching
+    // -----------------------------------------------------------------------
+
     private Intent createReady(boolean success) {
         return new Intent(SoilMoistureListener.INTENT_NAME).
                 putExtra("event", "ready").
@@ -252,15 +363,24 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
                 putExtra("address", address);
     }
 
+    private Intent createNewSample(SmSensor sensor) {
+        return new Intent(SoilMoistureListener.INTENT_NAME).
+                putExtra("event", "newSample").
+                putExtra("address", sensor.getDevice().getBtDevice().getAddress()).
+                putExtra("index", sensor.getIndex());
+    }
+
     public static void dispatchEvent(Intent intent, SoilMoistureListener listener) {
         String event = intent.getStringExtra("event");
         Log.i(TAG, "Dispatching event " + intent.getAction() + "/" + event);
         switch (event) {
             case "ready":
-                listener.onReady(intent.getBooleanExtra("success", false));
+                listener.onReady(
+                        intent.getBooleanExtra("success", false));
                 break;
             case "newDevice":
-                listener.onNewDevice(intent.getStringExtra("address"));
+                listener.onNewDevice(
+                        intent.getStringExtra("address"));
                 break;
             case "scanStarted":
                 listener.onScanStarted();
@@ -268,6 +388,11 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
             case "scanStopped":
                 listener.onScanStopped();
                 break;
+            case "newSample":
+                listener.onNewSample(
+                        intent.getStringExtra("address"),
+                        intent.getIntExtra("index", -1));
+                break;
             default:
                 break;
         }
diff --git a/app/src/main/java/io/trygvis/soilmoisture/MainActivity.java b/app/src/main/java/io/trygvis/soilmoisture/MainActivity.java
index 7aa3534..3a88f6c 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/MainActivity.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/MainActivity.java
@@ -16,9 +16,7 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.Button;
 import android.widget.ListAdapter;
-import android.widget.ListView;
 import android.widget.ProgressBar;
 import android.widget.TextView;
 import android.widget.Toast;
@@ -209,9 +207,18 @@ public class MainActivity extends ListActivity {
         }
     }
 
-    @Override
-    protected void onListItemClick(ListView l, View v, int position, long id) {
-        stopScan();
+    // -----------------------------------------------------------------------
+    //
+    // -----------------------------------------------------------------------
+
+    private void onDeviceClick(SmDevice device) {
+        Log.i(TAG, "onDeviceClick, device=" + device.getBtDevice().getId());
+    }
+
+    private void onSensorClick(SmSensor sensor) {
+        Log.i(TAG, "onSensorClick, device=" + sensor.getDevice().getBtDevice().getId() + "/" + sensor.getIndex());
+
+        sensor.readCurrentValue();
     }
 
     // -----------------------------------------------------------------------
@@ -223,16 +230,25 @@ public class MainActivity extends ListActivity {
         final TextView deviceAddress;
         final TextView rssi;
         final TextView info;
-        final ProgressBar spinner;
-        final Button connect;
 
         DeviceItem(View view) {
             this.deviceName = (TextView) view.findViewById(R.id.device_name);
             this.deviceAddress = (TextView) view.findViewById(R.id.device_address);
             this.rssi = (TextView) view.findViewById(R.id.device_rssi);
             this.info = (TextView) view.findViewById(R.id.device_info);
-            this.spinner = (ProgressBar) view.findViewById(R.id.device_spinner);
-            this.connect = (Button) view.findViewById(R.id.button_connect);
+        }
+    }
+
+    static class SensorItem {
+        final SmSensor sensor;
+        final TextView description;
+        final ProgressBar sensorProgress;
+
+        SensorItem(SmSensor sensor, View view) {
+            this.sensor = sensor;
+            this.description = (TextView) view.findViewById(R.id.description);
+            this.sensorProgress = (ProgressBar) view.findViewById(R.id.sensor_progress);
+            sensorProgress.setMax(1024);
         }
     }
 
@@ -254,18 +270,24 @@ public class MainActivity extends ListActivity {
             for (SmDevice d : devices) {
                 (d.isUseful() ? usefulDevices : unusefulDevices).add(d);
             }
-            List<SmSensor> monitors = new ArrayList<>();
+            List<SmSensor> sensors = new ArrayList<>();
             for (SmDevice d : devices) {
-                monitors.addAll(d.getSensors());
+                if (d.isUseful()) {
+                    sensors.addAll(d.getSensors());
+                }
             }
 
             if (groupByDevice) {
-                current.addAll(usefulDevices);
+//                current.addAll(usefulDevices);
+                for (SmDevice device : usefulDevices) {
+                    current.add(device);
+                    current.addAll(device.getSensors());
+                }
                 if (showAll) {
                     current.addAll(unusefulDevices);
                 }
             } else {
-                current.addAll(monitors);
+                current.addAll(sensors);
             }
             dataSetObservable.notifyChanged();
         }
@@ -374,50 +396,77 @@ public class MainActivity extends ListActivity {
             if (o instanceof SmDevice) {
                 return getSmDeviceView((SmDevice) o, view);
             } else if (o instanceof SmSensor) {
-                return getSoilMonitorView((SmSensor) o, view);
+                return getSoilSensorView((SmSensor) o, view);
             }
 
             throw new RuntimeException("Not implemented");
         }
 
         private View getSmDeviceView(SmDevice smDevice, View view) {
-
-            DeviceItem item;
             if (view == null) {
-                view = inflater.inflate(R.layout.listitem_device, null);
-                item = new DeviceItem(view);
-                view.setTag(item);
-                view.setClickable(false);
-            } else {
-                item = (DeviceItem) view.getTag();
+                view = inflater.inflate(R.layout.fragment_device, null);
+                view.setTag(new DeviceItem(view));
+                view.setClickable(true);
+                view.setOnClickListener(v -> onDeviceClick(smDevice));
             }
 
+            DeviceItem item = (DeviceItem) view.getTag();
+
             if (smDevice.getName() != null) {
                 item.deviceName.setText(smDevice.getName());
             } else {
                 item.deviceName.setText(R.string.unknown_device);
             }
-            item.deviceAddress.setText(smDevice.getBtDevice().getAddress());
+            String address = smDevice.getBtDevice().getAddress();
+
+            if (!smDevice.isProbed()) {
+                address += " not probed";
+            } else if (smDevice.isUseful()) {
+                address += " useful";
+            } else {
+                address += " not useful";
+            }
+
+            item.deviceAddress.setText(address);
 
             item.rssi.setText(getText(R.string.rssi) + ": " +
                     (smDevice.getBtDevice().getRssi() != 0 ? valueOf(smDevice.getBtDevice().getRssi()) : getText(R.string.unknown)));
 
-            if (smDevice.isUseful()) {
-                item.info.setText("number of sensors: " + smDevice.getSensors().size());
+            boolean useful = smDevice.isUseful();
+
+            if (useful) {
+                item.info.setText("Number of sensors: " + smDevice.getSensors().size());
             } else {
                 item.info.setText("");
             }
 
-            boolean useful = smDevice.isUseful();
-            item.spinner.setVisibility(useful ? View.GONE : View.VISIBLE);
-            item.connect.setVisibility(useful ? View.VISIBLE : View.GONE);
-            view.setClickable(useful);
+//            view.setClickable(useful);
 
             return view;
         }
 
-        private View getSoilMonitorView(SmSensor smSensor, View view) {
-            throw new RuntimeException("Not implemented");
+        private View getSoilSensorView(SmSensor smSensor, View view) {
+            if (view == null) {
+                view = inflater.inflate(R.layout.fragment_sensor, null);
+                view.setTag(new SensorItem(smSensor, view));
+                view.setClickable(true);
+                view.setOnClickListener(v -> onSensorClick(smSensor));
+            }
+
+            SensorItem item = (SensorItem) view.getTag();
+
+            Integer value = smSensor.getLastValue();
+            String text = "Connected: " + smSensor.getDevice().getBtDevice().connected();
+            text += ", value: " + (value == null ? "Unknown" : value);
+            item.description.setText(text);
+
+            if (value != null) {
+                item.sensorProgress.setProgress(value);
+            } else {
+                item.sensorProgress.setIndeterminate(true);
+            }
+
+            return view;
         }
     }
 
@@ -459,5 +508,10 @@ public class MainActivity extends ListActivity {
             deviceList.devices.add(device);
             deviceList.sort();
         }
+
+        @Override
+        public void onNewSample(String address, int sensor) {
+            deviceList.notifyDataSetChanged();
+        }
     }
 }
diff --git a/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java b/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java
index b51b3fa..4cb25f3 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java
@@ -18,16 +18,22 @@ import static io.trygvis.soilmoisture.SmDevice.SmCmdCode.SET_WARNING_VALUE;
 class SmDevice implements BtDevice.BtDeviceWrapper<SmDevice> {
     private final static String TAG = SmDevice.class.getSimpleName();
 
+    final DefaultSoilMoistureService smService;
+
     private final BtDevice<SmDevice> btDevice;
 
+    final long id;
+
     private String name;
 
     private Boolean isUseful;
 
     private List<SmSensor> sensors = new ArrayList<>();
 
-    public SmDevice(BtDevice<SmDevice> btDevice) {
+    public SmDevice(DefaultSoilMoistureService smService, BtDevice<SmDevice> btDevice, long id) {
+        this.smService = smService;
         this.btDevice = btDevice;
+        this.id = id;
         Log.i(TAG, "new device");
 
         name = btDevice.getName();
@@ -63,14 +69,21 @@ class SmDevice implements BtDevice.BtDeviceWrapper<SmDevice> {
     }
 
     public List<SmSensor> getSensors() {
+        if (!isUseful()) {
+            throw new IllegalStateException("Not a useful device");
+        }
         return sensors;
     }
 
+    void addSensor(SmSensor sensor) {
+        sensors.add(sensor);
+    }
+
     // -----------------------------------------------------------------------
-    //
+    // Message parsing and handling.
     // -----------------------------------------------------------------------
 
-    @SuppressWarnings("unchecked")
+    @SuppressWarnings({"unchecked", "StatementWithEmptyBody"})
     public static <T> T parseResponse(byte[] bytes, SmCmdCode code, Class<T> klass) {
         byte c = bytes[0];
 
@@ -78,10 +91,10 @@ class SmDevice implements BtDevice.BtDeviceWrapper<SmDevice> {
             throw new RuntimeException("Expected response of type " + code + ", got " + c);
         }
 
-        Object value = null;
         if (c == GET_SENSOR_COUNT.code) {
             return (T) new GetSensorCountRes(bytes[1]);
         } else if (c == GET_VALUE.code) {
+            return (T) new GetValueRes((bytes[2] & 0xff) << 8 | (bytes[1] & 0xff));
         } else if (c == SET_WARNING_VALUE.code) {
         } else if (c == GET_WARNING_VALUE.code) {
         } else if (c == SET_SENSOR_NAME.code) {
@@ -91,13 +104,6 @@ class SmDevice implements BtDevice.BtDeviceWrapper<SmDevice> {
         throw new RuntimeException("Unknown code: " + c);
     }
 
-    public void setSensorCount(int count) {
-        sensors = new ArrayList<>();
-        for (int index = 0; index < count; index++) {
-            sensors.add(new SmSensor(this, index));
-        }
-    }
-
     public static class GetSensorCountRes {
         public final int count;
 
@@ -106,6 +112,14 @@ class SmDevice implements BtDevice.BtDeviceWrapper<SmDevice> {
         }
     }
 
+    public static class GetValueRes {
+        public final int value;
+
+        public GetValueRes(int value) {
+            this.value = value;
+        }
+    }
+
     public static byte[] createGetSensorCountReq() {
         return new byte[]{
                 GET_SENSOR_COUNT.code
diff --git a/app/src/main/java/io/trygvis/soilmoisture/SmSensor.java b/app/src/main/java/io/trygvis/soilmoisture/SmSensor.java
index ec4b423..2a0d9cd 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/SmSensor.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/SmSensor.java
@@ -5,38 +5,57 @@ import java.util.Date;
 class SmSensor {
     private final SmDevice device;
 
-    private final int index;
+    public final long id;
+
+    public final int index;
+
+    private String name;
 
     private Date timestamp;
 
-    private int lastValue;
+    private Integer lastValue;
 
-    SmSensor(SmDevice device, int index) {
+    SmSensor(SmDevice device, long id, int index) {
         this.device = device;
+        this.id = id;
         this.index = index;
+        this.name = "Sensor #" + index;
     }
 
     public SmDevice getDevice() {
         return device;
     }
 
+    public long getId() {
+        return id;
+    }
+
     public int getIndex() {
         return index;
     }
 
-    public int getLastValue() {
-        return lastValue;
+    public String getName() {
+        return name;
     }
 
-    public void setLastValue(int lastValue) {
-        this.lastValue = lastValue;
+    public Integer getLastValue() {
+        return lastValue;
     }
 
     public Date getTimestamp() {
         return timestamp;
     }
 
-    public void setTimestamp(Date timestamp) {
+    // -----------------------------------------------------------------------
+    //
+    // -----------------------------------------------------------------------
+
+    public void readCurrentValue() {
+        device.smService.readCurrentValue(this);
+    }
+
+    void updateLastValue(Date timestamp, int lastValue) {
         this.timestamp = timestamp;
+        this.lastValue = lastValue;
     }
 }
diff --git a/app/src/main/java/io/trygvis/soilmoisture/SoilMoistureService.java b/app/src/main/java/io/trygvis/soilmoisture/SoilMoistureService.java
index 8100649..643fa08 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/SoilMoistureService.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/SoilMoistureService.java
@@ -25,7 +25,7 @@ public interface SoilMoistureService {
 
         public static final IntentFilter INTENT_FILTER = new IntentFilter(INTENT_NAME);
 
-        public void onReceive(Context context, Intent intent) {
+        public final void onReceive(Context context, Intent intent) {
             if (!intent.getAction().equals(INTENT_NAME)) {
                 return;
             }
@@ -44,5 +44,8 @@ public interface SoilMoistureService {
 
         public void onScanStopped() {
         }
+
+        public void onNewSample(String address, int sensor) {
+        }
     }
 }
diff --git a/app/src/main/java/io/trygvis/soilmoisture/Tables.java b/app/src/main/java/io/trygvis/soilmoisture/Tables.java
new file mode 100644
index 0000000..56e5041
--- /dev/null
+++ b/app/src/main/java/io/trygvis/soilmoisture/Tables.java
@@ -0,0 +1,24 @@
+package io.trygvis.soilmoisture;
+
+public class Tables {
+    public static String T_SM_DEVICE = "sm_device";
+    public static String T_SM_SENSOR = "sm_sensor";
+    public static String T_SOIL_SAMPLE = "soil_sample";
+
+    // sm_device
+    public static String C_ID = "id";
+    public static String C_BT_DEVICE = "bt_device";
+    public static String C_USEFUL = "useful";
+//    public static String C_NAME = "name";
+
+    // sm_sensor
+    public static String C_SM_DEVICE = "sm_device";
+    // name
+    public static String C_WARNING_VALUE = "warning_value";
+
+    // soil_sample
+    public static String C_SM_SENSOR = "sm_sensor";
+    public static String C_INDEX = "idx";
+    public static String C_TIMESTAMP = "timestamp";
+    public static String C_VALUE = "value";
+}