diff --git a/Application/src/main/java/fr/centralesupelec/students/clientble/GattConstants.java b/Application/src/main/java/fr/centralesupelec/students/clientble/GattConstants.java
index 7427c43..56414e2 100644
--- a/Application/src/main/java/fr/centralesupelec/students/clientble/GattConstants.java
+++ b/Application/src/main/java/fr/centralesupelec/students/clientble/GattConstants.java
@@ -45,6 +45,7 @@ public class GattConstants {
             "c093685d-005f-4d3c-8240-6d3020a2c608";
     public static final UUID WRITABLE_CHARACTERISTIC_UUID =
             UUID.fromString(WRITABLE_CHARACTERISTIC_UUID_STRING);
+    public static final int WRITABLE_CHARACTERISTIC_MAX_LENGTH = 20;
 
     // UUID du descripteur qui donne la configuration client d’une caractérisitique
     // (notification ou non.)
diff --git a/Application/src/main/java/fr/centralesupelec/students/clientble/SimpleDetailActivity.java b/Application/src/main/java/fr/centralesupelec/students/clientble/SimpleDetailActivity.java
index 72fd31e..2893e41 100644
--- a/Application/src/main/java/fr/centralesupelec/students/clientble/SimpleDetailActivity.java
+++ b/Application/src/main/java/fr/centralesupelec/students/clientble/SimpleDetailActivity.java
@@ -11,6 +11,7 @@ import android.content.IntentFilter;
 import android.content.ServiceConnection;
 import android.os.IBinder;
 import android.os.Bundle;
+import android.provider.SyncStateContract;
 import android.util.Log;
 import android.view.MenuItem;
 import android.view.View;
@@ -26,6 +27,7 @@ public class SimpleDetailActivity extends Activity {
     private TextView mConnectionStateView;
     private TextView mSensorValueView;
     private TextView mWritableValueView;
+    private TextView mFormView;
 
     private String mDeviceName;
     private String mDeviceAddress;
@@ -113,6 +115,7 @@ public class SimpleDetailActivity extends Activity {
         mDeviceAddressView = (TextView) findViewById(R.id.device_address);
         mDeviceAddressView.setText(mDeviceAddress);
 
+        mFormView = (TextView) findViewById(R.id.form_view);
         mConnectionStateView = (TextView) findViewById(R.id.connection_state);
         mSensorValueView = (TextView) findViewById(R.id.sensor_value);
         mWritableValueView = (TextView) findViewById(R.id.writable_value);
@@ -209,6 +212,18 @@ public class SimpleDetailActivity extends Activity {
         requestWritableValue();
     }
 
+    public void onSendClick(View view) {
+        Log.d(TAG, "onSendClick()");
+        byte [] text = mFormView.getText().toString().getBytes();
+        byte [] data = new byte[20];
+        int max = Math.min(text.length, GattConstants.WRITABLE_CHARACTERISTIC_MAX_LENGTH);
+        for (int i = 0; i < max; i++) {
+            data[i] = text[i];
+        }
+        Log.d(TAG, "envoi de: " + data.toString());
+        mBluetoothLeService.writeCharacterisitic(mWritableValueCharac, data);
+    }
+
     private void requestWritableValue() {
         BluetoothGattService privateService = mBluetoothLeService.getPrivateService();
         if (privateService == null) {
diff --git a/Application/src/main/res/layout/simple_detail_layout.xml b/Application/src/main/res/layout/simple_detail_layout.xml
index 2d74f6b..e513453 100644
--- a/Application/src/main/res/layout/simple_detail_layout.xml
+++ b/Application/src/main/res/layout/simple_detail_layout.xml
@@ -78,5 +78,21 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:onClick="onRefreshClick"
-        android:text="@string/label_refresh" />
+        android:text="@string/label_read" />
+
+    <EditText
+        android:id="@+id/form_view"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:ems="10"
+        android:hint="@string/hint_writable_value"
+        android:inputType="text"
+        android:maxLength="20" />
+
+    <Button
+        android:id="@+id/button2"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:onClick="onSendClick"
+        android:text="@string/label_write" />
 </LinearLayout>
\ No newline at end of file
diff --git a/Application/src/main/res/values/strings.xml b/Application/src/main/res/values/strings.xml
index c4398a6..c8a9805 100644
--- a/Application/src/main/res/values/strings.xml
+++ b/Application/src/main/res/values/strings.xml
@@ -35,4 +35,7 @@
     <string name="menu_scan">Scan</string>
     <string name="menu_stop">Stop</string>
     <string name="label_refresh">Update</string>
+    <string name="label_write">Write</string>
+    <string name="hint_writable_value">String to send… (max. 20 bytes)</string>
+    <string name="label_read">Read</string>
 </resources>