diff --git a/aruco_pose/CMakeLists.txt b/aruco_pose/CMakeLists.txt
index b73f9b54..25386ec2 100644
--- a/aruco_pose/CMakeLists.txt
+++ b/aruco_pose/CMakeLists.txt
@@ -119,7 +119,7 @@ generate_messages(
 
 ## Generate dynamic reconfigure parameters in the 'cfg' folder
 generate_dynamic_reconfigure_options(
-  cfg/DetectorParams.cfg
+  cfg/Detector.cfg
 )
 
 ###################################
diff --git a/aruco_pose/cfg/DetectorParams.cfg b/aruco_pose/cfg/Detector.cfg
similarity index 100%
rename from aruco_pose/cfg/DetectorParams.cfg
rename to aruco_pose/cfg/Detector.cfg
diff --git a/builder/assets/examples/get_telemetry.py b/builder/assets/examples/get_telemetry.py
new file mode 100644
index 00000000..fbbfb24f
--- /dev/null
+++ b/builder/assets/examples/get_telemetry.py
@@ -0,0 +1,11 @@
+# Information: https://clover.coex.tech/en/simple_offboard.html#gettelemetry
+
+import rospy
+from clover import srv
+
+rospy.init_node('flight')
+
+get_telemetry = rospy.ServiceProxy('get_telemetry', srv.GetTelemetry)
+
+# Print drone's state
+print(get_telemetry())
diff --git a/builder/image-software.sh b/builder/image-software.sh
index 079294b9..b2c92bda 100755
--- a/builder/image-software.sh
+++ b/builder/image-software.sh
@@ -148,6 +148,7 @@ my_travis_retry pip3 install --prefer-binary rpi_ws281x
 echo_stamp "Setup Monkey"
 mv /etc/monkey/sites/default /etc/monkey/sites/default.orig
 mv /root/monkey /etc/monkey/sites/default
+sed -i 's/SymLink Off/SymLink On/' /etc/monkey/monkey.conf
 systemctl enable monkey.service
 
 echo_stamp "Install Node.js"
diff --git a/builder/standalone-install.sh b/builder/standalone-install.sh
index 5b33a357..93b5799d 100755
--- a/builder/standalone-install.sh
+++ b/builder/standalone-install.sh
@@ -54,3 +54,6 @@ python3 -m pip install --upgrade pytest # TODO: https://github.com/CopterExpress
 cd /root/catkin_ws
 source devel/setup.bash
 catkin_make run_tests && catkin_test_results
+
+# Step 5: Install packages
+catkin_make install
diff --git a/clover/launch/clover.launch b/clover/launch/clover.launch
index f3ba21cd..86b65f80 100644
--- a/clover/launch/clover.launch
+++ b/clover/launch/clover.launch
@@ -12,7 +12,6 @@
     <arg name="led" default="true"/>
     <arg name="blocks" default="false"/>
     <arg name="rc" default="true"/>
-    <arg name="shell" default="true"/>
 
     <arg name="simulator" default="false"/> <!-- flag that we are operating on a simulated drone -->
 
@@ -91,9 +90,6 @@
         <param name="use_fake_gcs" value="false"/>
     </node>
 
-    <!-- Shell access through ROS service -->
-    <node name="shell" pkg="clover" type="shell" output="screen" if="$(arg shell)"/>
-
     <!-- Update static directory -->
     <node pkg="roswww_static" name="roswww_static" type="main.py" clear_params="true">
         <param name="default_package" value="clover"/>
diff --git a/clover/launch/mavros.launch b/clover/launch/mavros.launch
index 1eea4558..cb958447 100644
--- a/clover/launch/mavros.launch
+++ b/clover/launch/mavros.launch
@@ -6,13 +6,16 @@
     <arg name="viz" default="true"/>
     <arg name="respawn" default="true"/>
     <arg name="distance_sensor_remap" default="rangefinder/range"/>
+    <arg name="usb_device" default="/dev/px4fmu"/>
+    <arg name="prefix" default="" unless="$(eval fcu_conn == 'usb')"/>
+    <arg name="prefix" default="bash -c 'while [ ! -e $(arg usb_device) ]; do sleep 1; done; $0 $@'" if="$(eval fcu_conn == 'usb')"/>
 
-    <node pkg="mavros" type="mavros_node" name="mavros" required="false" clear_params="true" respawn="$(arg respawn)" unless="$(eval fcu_conn == 'none')" respawn_delay="1" output="screen">
+    <node pkg="mavros" type="mavros_node" name="mavros" launch-prefix="$(arg prefix)" required="false" clear_params="true" respawn="$(arg respawn)" unless="$(eval fcu_conn == 'none')" respawn_delay="1" output="screen">
         <!-- UART connection -->
         <param name="fcu_url" value="/dev/ttyAMA0:921600" if="$(eval fcu_conn is None or fcu_conn == 'uart')"/>
 
         <!-- USB connection -->
-        <param name="fcu_url" value="/dev/px4fmu" if="$(eval fcu_conn == 'usb')"/>
+        <param name="fcu_url" value="$(arg usb_device)" if="$(eval fcu_conn == 'usb')"/>
 
         <!-- sitl before PX4 1.9.0 -->
         <param name="fcu_url" value="udp://@$(arg fcu_ip):14557" if="$(eval fcu_conn == 'udp')"/>
diff --git a/clover/test/basic.py b/clover/test/basic.py
index bc3646b5..283180ed 100755
--- a/clover/test/basic.py
+++ b/clover/test/basic.py
@@ -33,19 +33,3 @@ def test_web_video_server(node):
         # Python 3
         import urllib.request as urllib
     urllib.urlopen("http://localhost:8080").read()
-
-def test_shell(node):
-    execute = rospy.ServiceProxy('exec', srv.Execute)
-    execute.wait_for_service(5)
-
-    res = execute(cmd='echo foo')
-    assert res.code == 0
-    assert res.output == 'foo\n'
-
-    res = execute(cmd='foo')
-    assert res.code == 32512
-    assert res.output == ''
-
-    res = execute(cmd='ls foo')
-    assert res.code == 512
-    assert res.output == ''
diff --git a/clover/www/clover_version b/clover/www/clover_version
new file mode 120000
index 00000000..ac5ca460
--- /dev/null
+++ b/clover/www/clover_version
@@ -0,0 +1 @@
+/etc/clover_version
\ No newline at end of file
diff --git a/clover/www/index.html b/clover/www/index.html
index 676b48e5..fbae51c8 100644
--- a/clover/www/index.html
+++ b/clover/www/index.html
@@ -13,15 +13,15 @@
 
 <div class="version"></div>
 
-<script src="js/roslib.js"></script>
 <script type="text/javascript">
 	document.querySelector("#wvs").href = location.protocol + '//' + location.hostname + ':8080';
 	document.querySelector("#butterfly").href = location.protocol + '//' + location.hostname + ':57575';
 
 	// Determine image version
-	var ros = new ROSLIB.Ros({ url: 'ws://' + location.hostname + ':9090' });
-	var exec = new ROSLIB.Service({ ros: ros, name : '/exec', serviceType : 'clover/Execute' });
-	exec.callService(new ROSLIB.ServiceRequest({ cmd: 'cat /etc/clover_version' }), function(result) {
-		document.querySelector('.version').innerHTML = 'Version: ' + result.output;
+	fetch('clover_version').then(function(response) {
+		if (response.status !== 200) return;
+		response.text().then(function(text) {
+			document.querySelector('.version').innerHTML = 'Version: ' + text;
+		});
 	});
 </script>
diff --git a/clover_blocks/src/clover_blocks b/clover_blocks/src/clover_blocks
index fdd49601..4000df8e 100755
--- a/clover_blocks/src/clover_blocks
+++ b/clover_blocks/src/clover_blocks
@@ -11,7 +11,8 @@
 from __future__ import print_function
 
 import rospy
-import os
+import os, sys
+import traceback
 import threading
 import re
 import uuid
@@ -116,7 +117,12 @@ def run(req):
                 rospy.loginfo('Program forced to stop')
             except Exception as e:
                 rospy.logerr(str(e))
-                error_pub.publish(str(e))
+                traceback.print_exc()
+                etype, value, tb = sys.exc_info()
+                fmt = traceback.format_exception(etype, value, tb)
+                fmt.pop(1) # remove 'clover_blocks' file frame
+                exc_info = ''.join(fmt)
+                error_pub.publish(str(e) + '\n\n' + exc_info)
 
             rospy.loginfo('Program terminated')
             running_lock.release()
diff --git a/clover_simulation/CMakeLists.txt b/clover_simulation/CMakeLists.txt
index 7ee6b14e..a4a6a2b0 100644
--- a/clover_simulation/CMakeLists.txt
+++ b/clover_simulation/CMakeLists.txt
@@ -52,7 +52,7 @@ target_compile_options(throttling_camera PRIVATE -std=c++11)
 add_dependencies(throttling_camera ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
 
 install(DIRECTORY launch DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION})
-install(DIRECTORY meshes DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION})
+install(DIRECTORY models DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION})
 install(DIRECTORY resources DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION})
 
 catkin_install_python(PROGRAMS scripts/aruco_gen
diff --git a/docs/en/copterhack2021.md b/docs/en/copterhack2021.md
index 136d455b..cd8d9670 100644
--- a/docs/en/copterhack2021.md
+++ b/docs/en/copterhack2021.md
@@ -1,6 +1,6 @@
 # CopterHack 2021
 
-CopterHack 2021 is a team competition for the development of open source projects for the Clover quadcopter platform.
+CopterHack 2021 is a team competition for the development of open source projects for the Clover quadcopter platform. Fifty-four teams from 12 countries took part in the competition.
 
 All information about the event can be found on the official website: https://coex.tech/copterhack.
 
diff --git a/docs/en/programming.md b/docs/en/programming.md
index a55e802c..fd72298b 100644
--- a/docs/en/programming.md
+++ b/docs/en/programming.md
@@ -34,7 +34,15 @@ Read more in the [GPS connection](gps.md) article.
 
 > **Info** For studying Python programming language, see [tutorial](https://www.learnpython.org/en/Welcome).
 
-After you've configured your positioning system, you can start writing programs for autonomous flights. Use the [SSH connection to the Raspberry Pi](ssh.md) to run your scripts. In order to run a Python script use the `python3` command:
+After you've configured your positioning system, you can start writing programs for autonomous flights. Use the [SSH connection to the Raspberry Pi](ssh.md) to run your scripts.
+
+Before the first flight it's recommended to check the Clover's configuration with [selfcheck.py utility](selfcheck.md):
+
+```bash
+rosrun clover selfcheck.py
+```
+
+In order to run a Python script use the `python3` command:
 
 ```bash
 python3 flight.py
diff --git a/docs/en/snippets.md b/docs/en/snippets.md
index ce52b430..6c8d2127 100644
--- a/docs/en/snippets.md
+++ b/docs/en/snippets.md
@@ -359,3 +359,28 @@ calibrate_gyro()
 ```
 
 > **Note** In process of calibration the drone should not be moved.
+
+<!-- markdownlint-disable MD044 -->
+
+### # {#aruco-detect-enabled}
+
+<!-- markdownlint-enable MD044 -->
+
+Enable and disable [ArUco markers recognition](aruco_marker.md) dynamically (for example, for saving CPU resources):
+
+```python
+import rospy
+import dynamic_reconfigure.client
+
+# ...
+
+client = dynamic_reconfigure.client.Client('aruco_detect')
+
+# Turn markers recognition off
+client.update_configuration({'enabled': False})
+
+rospy.sleep(5)
+
+# Turn markers recognition on
+client.update_configuration({'enabled': True})
+```
diff --git a/docs/ru/copterhack2021.md b/docs/ru/copterhack2021.md
index ee0446bf..0b93a3b3 100644
--- a/docs/ru/copterhack2021.md
+++ b/docs/ru/copterhack2021.md
@@ -1,6 +1,6 @@
 # CopterHack 2021
 
-CopterHack 2021 – это командный конкурс по разработке проектов с открытым исходным кодом для платформы квадрокоптера "Клевер".
+CopterHack 2021 – это командный конкурс по разработке проектов с открытым исходным кодом для платформы квадрокоптера "Клевер". В конкурсе приняло участие 54 команды из 12 стран.
 
 Все информацию о мероприятии смотрите на официальном сайте: https://ru.coex.tech/copterhack.
 
diff --git a/docs/ru/programming.md b/docs/ru/programming.md
index 3acb253c..ef8fe8e8 100644
--- a/docs/ru/programming.md
+++ b/docs/ru/programming.md
@@ -32,9 +32,17 @@
 
 ## Автономный полет {#flight}
 
-> **Info** Для изучения языка программирования Python обращайтесь к [самоучителю](https://pythonworld.ru/samouchitel-python).
+> **Info** Для изучения языка программирования Python вы можете обратиться к [самоучителю](https://pythonworld.ru/samouchitel-python).
 
-После настройки системы позиционирования становится возможным написание скриптов для автономных полетов. Для выполнения скриптов [подключитесь в Raspberry Pi по SSH](ssh.md). Для того, чтобы запустить Python-скрипт, используйте команду `python3`:
+После настройки системы позиционирования становится возможным написание скриптов для автономных полетов. Для выполнения скриптов [подключитесь в Raspberry Pi по SSH](ssh.md).
+
+Перед первым полетом рекомендуется проверить конфигурацию Клевера при помощи [утилиты selfcheck.py](selfcheck.md):
+
+```bash
+rosrun clover selfcheck.py
+```
+
+Для того, чтобы запустить Python-скрипт, используйте команду `python3`:
 
 ```bash
 python3 flight.py
diff --git a/docs/ru/snippets.md b/docs/ru/snippets.md
index ec70652a..e7219bf7 100644
--- a/docs/ru/snippets.md
+++ b/docs/ru/snippets.md
@@ -377,3 +377,28 @@ calibrate_gyro()
 ```
 
 > **Note** В процессе калибровки гироскопов дрон нельзя двигать.
+
+<!-- markdownlint-disable MD044 -->
+
+### # {#aruco-detect-enabled}
+
+<!-- markdownlint-enable MD044 -->
+
+Динамически включать и отключать [распознавание ArUco-маркеров](aruco_marker.md) (например, для экономии ресурсов процессора):
+
+```python
+import rospy
+import dynamic_reconfigure.client
+
+# ...
+
+client = dynamic_reconfigure.client.Client('aruco_detect')
+
+# Turn markers recognition off
+client.update_configuration({'enabled': False})
+
+rospy.sleep(5)
+
+# Turn markers recognition on
+client.update_configuration({'enabled': True})
+```
diff --git a/redirects.json b/redirects.json
index 134dae7c..8d4a04ff 100644
--- a/redirects.json
+++ b/redirects.json
@@ -49,7 +49,8 @@
 
         { "from": "modes/", "to": "ru/modes.html" },
         { "from": "firmware/", "to": "en/firmware.html" },
-        { "from": "simple_offboard/", "to": "ru/simple_offboard.html" },
+        { "from": "simple_offboard/", "to": "en/simple_offboard.html" },
+        { "from": "offboard/", "to": "en/simple_offboard.html" },
         { "from": "camera/", "to": "ru/camera.html" },
         { "from": "snippets/", "to": "ru/snippets.html" },
         { "from": "optical_flow/", "to": "ru/optical_flow.html" },
@@ -61,6 +62,7 @@
         { "from": "camera_setup/", "to": "en/camera_setup.html" },
         { "from": "power/", "to": "en/power.html" },
         { "from": "connection/", "to": "en/connection.html" },
+        { "from": "clover_vm/", "to": "en/simulation_vm.html" },
 
         { "from": "ru/microsd_images.html", "to": "image.html" },
         { "from": "en/microsd_images.html", "to": "image.html" }