diff --git a/docs/en/camera.md b/docs/en/camera.md
index 16b68c9c..2620facd 100644
--- a/docs/en/camera.md
+++ b/docs/en/camera.md
@@ -1,12 +1,12 @@
# Working with the camera
-To work with the main camera, make sure it is enabled in file `~/catkin_ws/src/clever/clever/launch/clever.launch`:
+Make sure the camera is enabled in the `~/catkin_ws/src/clever/clever/launch/clever.launch` file:
```xml
```
-Also make sure that [correct position and orientation are indicated] for the camera (camera_frame.md).
+Also make sure that [position and orientation of the camera](camera_frame.md) is correct.
The `clever` package must be restarted after the launch-file has been edited:
@@ -14,11 +14,41 @@ The `clever` package must be restarted after the launch-file has been edited:
sudo systemctl restart clever
```
-For monitoring images from the camera, you may use rqt or [web_video_server](web_video_server.md).
+You may use rqt or [web_video_server](web_video_server.md) to view the camera stream.
+
+## Troubleshooting
+
+If the camera stream is missing, try using the [`raspistill`](https://www.raspberrypi.org/documentation/usage/camera/raspicam/raspistill.md) utility to check whether the camera works.
+
+First, stop the Clever service:
+
+```bash
+sudo systemctl stop clever
+```
+
+Then use `raspistill` to capture an image from the camera:
+
+```bash
+raspistill -o test-image.jpeg
+```
+
+If it doesn't work, check the camera cable connections and the cable itself. Replace the cable if it is damaged. Also, make sure the camera screws don't touch any components on the camera board.
+
+## Camera parameters
+
+Some camera parameters, such as image size, FPS cap, and exposure, may be configured in the `main_camera.launch` file. The list of supported parameters can be found [in the cv_camera repository](https://github.com/OTL/cv_camera#parameters).
+
+Additionally you can specify an arbitrary capture parameter using its [OpenCV code](https://docs.opencv.org/3.3.1/d4/d15/group__videoio__flags__base.html). For example, add the following parameters to the camera node to set exposition manually:
+
+```xml
+
+
+
+```
## Computer vision
-For implementation of the computer vision algorithms, it is recommended to use the [OpenCV] library that is pre-installed in [the SD card image] (image.md) (https://opencv.org).
+The [SD card image](image.md) comes with a preinstalled [OpenCV](https://opencv.org) library, which is commonly used for various comupter vision-related tasks. Additional libraries for converting from ROS messages to OpenCV images and back are preinstalled as well.
### Python
@@ -66,11 +96,11 @@ The obtained images can be viewed using [web_video_server](web_video_server.md).
To program actions of the copter upon detection of [QR codes](https://en.wikipedia.org/wiki/QR_code) you can use the [ZBar] library (http://zbar.sourceforge.net). It should be installed using pip:
-```(bash)
+```bash
sudo pip install zbar
```
-Recognizing QR codes in Python:
+QR codes recognition in Python:
```python
import cv2
@@ -100,7 +130,7 @@ def image_callback(data):
image_sub = rospy.Subscriber('main_camera/image_raw', Image, image_callback, queue_size=1)
```
-The script will take up to 100% CPU capacity. To slow down the script artificially, you can run [throttling](http://wiki.ros.org/topic_tools/throttle) of frames from the camera, for example, at 5 Hz (`main_camera.launch`):
+The script will take up to 100% CPU capacity. To slow down the script artificially, you can use [throttling](http://wiki.ros.org/topic_tools/throttle) of frames from the camera, for example, at 5 Hz (`main_camera.launch`):
```xml
+
+
+```
+
## Компьютерное зрение
Для реализации алгоритмов компьютерного зрения рекомендуется использовать предустановленную на [образ SD-карты](image.md) библиотеку [OpenCV](https://opencv.org).
diff --git a/docs/ru/copterhack2019.md b/docs/ru/copterhack2019.md
new file mode 100644
index 00000000..6e96e0bf
--- /dev/null
+++ b/docs/ru/copterhack2019.md
@@ -0,0 +1,19 @@
+# Copter Hack 2019
+
+Хакатон [Copter Hack 2018](https://copterexpress.timepad.ru/event/768108/) проходит 11–13 октября в Технополисе "Москва".
+
+Официальный сайт: https://ru.coex.tech/copterhack.
+
+Чат хакатона: https://t.me/CopterHack.
+
+Timepad: https://copterexpress.timepad.ru/event/1017592/.
+
+## Информация для участников
+
+## Лекции
+
+Лекция 1: введение – https://www.youtube.com/watch?v=cjtmZNuq7z0.
+
+Лекция 2: настройка полетного контроллера – https://www.youtube.com/watch?v=PJNDYFPZQms.
+
+Лекция 3: архитектура полетного контроллера PX4 – https://www.youtube.com/watch?v=_jl7FImq3jk.