added general notes

docs/notes/notes_intel_realsense.txt

@@ -0,0 +1,44 @@
+Installing Intel RealSense drivers:
+###################################
+echo 'deb http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial main' || sudo tee /etc/apt/sources.list.d/realsense-public.list
+sudo add-apt-repository "deb http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial main"
+sudo apt-get update
+sudo apt-get install librealsense2-dev
+sudo apt-get install librealsense2-dkms # enter a key for installing driver when asked (in my case the pw was realsense2019bt)
+sudo apt-get install librealsense2-utils
+
+Check if drivers were installed sucessfully:
+modinfo uvcvideo | grep "version:" # -> this should report the realsense camera driver
+
+
+# Installing the ROS package (assuming ros base is installed):
+Install dependencies:
+sudo apt-get install ros-kinetic-cv-bridge -y
+sudo apt-get install ros-kinetic-image-transport
+sudo apt-get install ros-kinetic-tf -y
+sudo apt-get install ros-kinetic-diagnostic-updater -y
+sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
+sudo apt-get update
+sudo apt-get install ros-kinetic-ddynamic-reconfigure -y
+
+# clone github repo:
+git clone https://github.com/IntelRealSense/realsense-ros.git
+cd realsense-ros/
+git checkout `git tag | sort -V | grep -P "^\d+\.\d+\.\d+" | tail -1`
+mkdir -p ~/realsense_catkin_ws/src/realsense
+mv * ~/realsense_catkin_ws/src/realsense/
+
+cd ~/realsense_catkin_ws/src/
+catkin_init_workspace
+cd .. 
+catkin_make clean
+catkin_make -DCATKIN_ENABLE_TESTING=False -DCMAKE_BUILD_TYPE=Release
+catkin_make install
+echo "source ~/realsense_catkin_ws/devel/setup.bash" >> ~/.bashrc
+source ~/.bashrc
+
+Test with:
+roslaunch realsense2_camera rs_camera.launch
+
+Possible issue:
+The camera requires a USB 3 port to provide full resolution streams

docs/notes/notes_ros_messages.txt

@@ -0,0 +1,56 @@
+Creating ros package with catkin and adding custom messages:
+############################################################
+1. Create a workspace:
+----------------------
+$ mkdir catkin_ws
+$ cd catkin_ws
+$ mkdir src
+$ catkin_make
+$ source devel/setup.bash
+
+2. Create the package:
+----------------------
+$ cd catkin_ws/src
+$ catkin_create_pkg <package_name> std_msgs rospy roscpp
+$ cd ..
+$ catkin_make # this build the package
+
+3. Create the custom messages:
+------------------------------
+$ cd catkin_ws/src/<package_name>
+$ mkdir msg
+$ cd msg
+$ echo "int64 num" > Num.msg
+Then edit the package.xml file and add the following:
+  <build_depend>message_generation</build_depend>
+  <exec_depend>message_runtime</exec_depend>
+
+Also edit CMakeLists.txt and to the find_package() function add:
+ message_generation
+and to the catkin_package() add:
+ CATKIN_DEPENDS message_runtime
+
+Then, find add_message_files() (uncomment if necessary) and change it to the following:
+add_message_files(
+  FILES
+  Num.msg
+)
+
+Finally, uncomment the generate_messages() function such that it reads:
+ generate_messages(
+   DEPENDENCIES
+   std_msgs
+ )
+
+To build the new messages do the following:
+$ cd catkin_ws
+$ catkin_make # builds the new messages
+$ catkin_make install
+
+As the last step, source the setup.bash:
+$ . install/setup.bash
+
+Now the new messages should be available and you can find them with
+$ rosmsg list
+
+Don't forget to source the setup.bash everytime you want to use the messages!