Drone Skyways

ROS Installation

• Ensure that your onboard computer supports 64-bit Ubuntu 20.04, either server or desktop.

• Download ROS 1 (Noetic) and ROS 2 (Foxy) from the links given below.

  ROS 1 (Noetic): http://wiki.ros.org/noetic/Installation/Ubuntu

  ROS 2 (Foxy): https://docs.ros.org/en/foxy/Installation/Ubuntu-Install-Debians.html

Note: ROS 1 installation is required only on onboard computer (or for development). For running a Ground Station, only ROS 2 is required.

• Install catkin and colcon build systems.

sudo apt install python3-catkin-tools -y
sudo apt install python3-colcon-common-extensions -y

• Install ros1_bridge for ROS 2 - ROS 1 message conversions

sudo apt install ros-foxy-ros1-bridge

• Install MAVROS for ROS 1 communication with PX4 Autopilot.

sudo apt install ros-noetic-mavros ros-noetic-mavros-extras

• After this install GeographicLib Datasets.

wget https://raw.githubusercontent.com/mavlink/mavros/master/mavros/scripts/install_geographiclib_datasets.sh
sudo bash install_geographiclib_datasets.sh

NOTE: In case you are unable to install GeographicLib Datasets, check you clock. Time on the computer should be proper. You can set time using this command.

sudo date -s "$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z"

Environment Setup

• Create two workspaces, one for ROS 1 and another for ROS 2.

mkdir -p catkin_ws/src
mkdir -p colcon_ws/src

• Clone the repository and checkout the ros-1 branch in catkin_ws/src and follow these instructions to build your workspace.

source /opt/ros/noetic/setup.bash
cd ~/catkin_ws/src
git clone https://github.com/Shobuj-Paul/skyways.git
cd skyways
git checkout ros-1
cd ../..
catkin build

• Clone the repository and checkout ros-2 branch (default branch so you can leave as it is) in colcon_ws/src and follow these instructions to build your workspace.

source /opt/ros/foxy/setup.bash
cd ~/colcon_ws/src
git clone https://github.com/Shobuj-Paul/skyways.git
cd skyways
git checkout ros-2
cd ../..
colcon build --symlink-install

• Next we need to create aliases for easy sourcing of workspaces. Bash scripts for these have been created in the scripts folder. Change the workspace names and paths accordingly if you have created them in a different directory.

• Add these aliases to your ~/.bashrc file. With this you will be able to source your workspaces (both overlay and underlay) with commands noetic (for ROS 1 and catkin_ws) and foxy (for ROS 2 and colcon_ws).

alias foxy='source ~/colcon_ws/src/skyways/scripts/foxy.sh'
alias noetic='source ~/catkin_ws/src/skyways/scripts/noetic.sh'

• Set an environment variable in your ~/.bashrc file to avoid explicity mentioning it everytime you run you client or control codes.

export DRONE_ID="<name of your drone>"

You can check your variable using this command.

echo $DRONE_ID

Drone Flight Setup

This manual setup is no longer necessary, you can follow the instructions given in the next part to automate this process.

• Make sure that the onboard computer has permission to read and write to /dev/ttyACM0 port. If that is not the case, you can set permission using the following command.

sudo chmod 777 /dev/ttyACM0

This is done manually and is not permanent, each login requires you to do this manually. It is better to add yourself to dialout group.

usermod -a -G dialout $USER
sudo adduser $USER

For Nvidia development boards this alone does not work. You need to set udev rules.

sudo echo 'ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="09cb", OWNER=$USER, MODE="0777", GROUP="nvidia"' >> /etc/udev/rules.d/50-usb.rules

Logout and login again for changes to take effect.

• Open up 4 terminal windows.
• Source ROS 1. Start MAVROS connection to PX4. Make sure the PX4 controller (Pixhawk or Cube) is connected via serial to USB port on the onboard computer.

noetic
roslaunch skyways px4.launch ID:=$DRONE_ID fcu_url:="/dev/ttyACM0"

• Source ROS 1. Run your control code.

noetic
rosrun skyways setpoint_mission $DRONE_ID

• Source ROS 1. Source ROS 2. Run ros1_bridge.

noetic
foxy
ros2 run ros1_bridge dynamic_bridge --bridge-all-topics

• Source ROS 2. Run ROS 2 client for sending flight request.

foxy
ros2 run skyways drone_client $DRONE_ID

Drone Flight Setup on Startup

• Enable automatic login on Ubuntu from settings.
• Add terminal as a start up process in Startup Applications with the following command.

gnome-terminal

• Add the following line to the end of your ~/.bashrc file.

source ~/colcon_ws/src/skyways/scripts.startup.sh

• Reboot. You can check on your Ground Station PC whether the topics are broadcasted via this command.

foxy
ros2 topic list

Ground Station Command

• Clone the repository in a ROS 2 workspace on your ground station and build.

source /opt/ros/foxy/setup.bash
mkdir -p colcon_ws/src
cd colcon_ws/src
git clone https://github.com/Shobuj-Paul/skyways.git
cd skyways
git checkout ros-2
cd ../..
colcon build --symlink-install

• You can log waypoints from the drone using the following command

ros2 run skyways waypoint_logger <Drone ID>

• Start the ROS 2 server on Ground Station.

foxy
ros2 run skyways drone_server

Development

• All online flight behaviors need to be programmed in ROS 1 package.
• All offline flight planning needs to programmed in ROS 2 package, within the drone_server.cpp file, void data(const std::shared_ptr<skyways::srv::DataPacket::Request> request, std::shared_ptr<skyways::srv::DataPacket::Response> response) function.

Network

• To set up Wifi hotspot with Alfa Wifi router, connect the router and run the following command.

nmcli dev wifi hotspot ifname wlx00c0ca980d57 ssid alfa password "abcd1234"