In this post, I'm running MAVROS in the TX2 connected to the Pixhawk 4 with PX4 and QGroundControl. First of all, we need to install ROS Melodic from the ROS official website
Configure your Ubuntu repositories to allow "restricted," "universe," and "multiverse." You can follow the Ubuntu guide for instructions on doing this.
Setup your computer to accept software from packages.ros.org.
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
First, make sure your Debian package index is up-to-date:
sudo apt update sudo apt install ros-melodic-desktop-full
Before you can use ROS, you will need to initialize rosdep. rosdep enables you to easily install system dependencies for source you want to compile and is required to run some core components in ROS.
sudo rosdep init rosdep update
It's convenient if the ROS environment variables are automatically added to your bash session every time a new shell is launched:
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc source ~/.bashrc
Up to now you have installed what you need to run the core ROS packages. To create and manage your own ROS workspaces, there are various tools and requirements that are distributed separately. For example, rosinstall is a frequently used command-line tool that enables you to easily download many source trees for ROS packages with one command.
To install this tool and other dependencies for building ROS packages, run:
sudo apt install python-rosinstall python-rosinstall-generator python-wstool build-essential
After installing ROS-melodic we need to create our catkin workspace and install MAVROS and then build everything.
jetson@desktop:~$ sudo apt-get install python-catkin-tools python-rosinstall-generator -y
Create the workspace: unneeded if you already has workspace:
jetson@desktop:~$ mkdir -p ~/catkin_ws/src jetson@desktop:~$ cd ~/catkin_ws jetson@desktop:~$ catkin init jetson@desktop:~$ wstool init src
Install MAVLink we use the Kinetic reference for all ROS distros as it's not distro-specific and up to date:
jetson@desktop:~$ rosinstall_generator --rosdistro kinetic mavlink | tee /tmp/mavros.rosinstall
Install MAVROS: get source (upstream - released):
jetson@desktop:~$ rosinstall_generator --upstream mavros | tee -a /tmp/mavros.rosinstall
Create workspace & deps:
jetson@desktop:~$ wstool merge -t src /tmp/mavros.rosinstall jetson@desktop:~$ wstool update -t src -j4 jetson@desktop:~$ rosdep install --from-paths src --ignore-src -y
Install GeographicLib datasets:
jetson@desktop:~$ sudo ./src/mavros/mavros/scripts/install_geographiclib_datasets.sh
Build source:
jetson@desktop:~$ catkin build
Make sure that you use setup.bash or setup.zsh from workspace. Else rosrun can't find nodes from this workspace.
jetson@desktop:~$ source devel/setup.bash
take it from Mavros github offcial
In this part, I will explain how to setup the JTX2 devkit to connect with the PiXHawk 4 (PX4) First, we need to locate the UART 1 in the TX2 devkit
Here's our UART 1:
and here we have the serial port header connections:
If you're running the last Jetpack(4.2.3) you don't need to change the serial device port from /dev/ttyACM to /dev/ttyTHS2, it is already done in the last jetpack. Perhaps we need to give a permission to the port /dev/ttyTHS2 and add the user to the group running these commands:
sudo stop modemmanager
sudo usermod -a -G dialout $USER
before star the software settings we need to connect the Pixhawk to the JTX2 via telem2
| PIN | Jetson TX2 | PIN | Telem 2 |
|---|---|---|---|
| 1 | GND | 6 | GND |
| 2 | RTS | Not connect | |
| 3 | NC | Not connect | |
| 4 | Rx | 2 | Tx |
| 5 | Tx | 3 | Rx |
| 6 | CTS | Not connect |
Now we are ready to go to the Pixhawk settings.
Connect the Pixhawk via usb to the PC (running Windows or Mac). Do not connect the battery. Please refer to this video to setup the pixhawk with basic settings:
https://www.youtube.com/watch?v=6Dk7oSKf4wE&t=482s
after setting the Pixhawk we have to modify some parameters. To do that open QGroundControl and go to parameters:
Now look for the tab "Mavlink" and change these parameters:
MAV_1_CONFIG = TELEM 2
MAV_2_CONFIG = TELEM 2
reboot the vehicle and go again to the mavlink tab and change these parameters:
MAV_1_MODE = Onboard
MAV_1_RATE= 921600 baud
MAV_1_FORWARD = True
if these parameters does not appears change these:
MAV_2_MODE = Onboard
MAV_2_RATE= 921600 baud
MAV_2_FORWARD = True
If everything is fine then you are going to see something like this:
after this go to the Serial Tab and change:
SER_TEL2_BAUD = 921600
After this is done reboot the vehicle and disconnect the USB cable from the Windows PC.
##Running MAVROS in the TX2 with the Pixhawk
In the TX2 run: jetson@desktop:~$ roscore
In other terminal run:
roslaunch mavros px4.launch fcu_url:="/dev/ttyTHS2:921600" gcs_url:="udp://:[email protected]:14550"