ROS2 Foxy Fitzroy Install Guide

Follow the guide at the link below to install ROS2 Foxy Fitzroy on your NavQ running the Demo image.

FastRTPS and the microRTPS Agent

FastRTPS and the microRTPS agent are needed on NavQ in order to bridge uORB topics from PX4 to ROS2 on NavQ over a UART or UDP connection. Follow the guide below to build and install these packages.

Follow the link below for more details on microRTPS and PX4 ROS Com:

Installing FastRTPS and PX4 ROS Com on NavQ

Prerequisites

FastRTPS installation

First, we will install the FastRTPS project from eProsima. Use the following commands below to do so:

px4_ros_com installation

Next, we will build and install the necessary software that will allow us to use ROS2 to communicate with the microRTPS bridge. First, run the following commands:

Run the following commands to enable a 1GB swapfile:

Now, build the workspace:

Sourcing ROS2 bash files

In order to run all of your specific ROS2 software successfully, you must source the install/setup.bash files in each of your ROS2 workspace folders. Add the following lines to your .bashrc to do so:

Next steps

Continue to the next page to set up a systemd service that will automatically start the micrortps agent on your NavQ. The guide will also cover how to automatically start the client on the FMU.

Creating a systemd service to auto-start the microRTPS agent on NavQ

Generate a start up script for the micrortps client under /usr/local/bin

with content

Save the file and exit nano. Make the file executable

Generate a systemd service file to start the startup script at boot

with content

Save the file and exit nano. Check if the process starts

You should see an state active (running), quit with <q> Enable the systemd service file finally to be active at boot

Auto-start the microRTPS client on the FMU

Building PX4 with microRTPS

In order to use the microRTPS client on NavQ, you'll need to build PX4 with the _rtps tag for the fmuk66-v3 build target. To do this, you will need to have both the FastRTPS and Fast-RTPS-Gen packages installed. You can just follow the previous guide on your Linux development VM or computer.

Once you have successfully installed those two packages, you can navigate to your cloned PX4 repository and run the following:

Flashing your FMU with the updated binary

You will need to flash your FMU with the updated RTPS binary. If you don't know how to do this yet, follow the guide here:

Creating a startup file on the SD card

To make the microRTPS client start at boot on the FMU, you will need to have an SD card inserted. On your SD card, make a file at /etc/extras.txt and insert one of the following options:

Overview

In this section, we will guide you through the process needed to detect AprilTags on your NavQ. There are a few things that need to be done to accomplish this:

1. Install ROS2 image tools

2. Build and install AprilTag detection nodes

3. Calibrate the camera on your NavQ using a checkerboard pattern

Prerequisites

Before we start, you will need a few things:

Checkerboard

To create a checkerboard for camera calibration, download this PDF:

Desktop Setup

In order to calibrate the camera, you will need to set up your NavQ with a mouse, keyboard, and monitor. Use the included microUSB hub and HDMI connector to do so.

Installing required ROS2 software

Install the following packages with the apt package manager by running the commands below:

Once that is finished, move on to the next step.

Calibrating the camera

Hook up your NavQ to a monitor with the provided HDMI cord and connect a USB mouse + keyboard through the included microUSB hub. Open the terminal by clicking the icon at the top left of the screen and open the bash shell by running:

Have your printed checkerboard ready in a well lit environment and run the camera calibration software by running the following commands:

Now use the link in the note above to run through calibarating the camera.

Detecting AprilTags

Building apriltag_msgs

A prerequisite for the apriltag_ros node is apriltag_msgs. Clone the repo and build it by running these commands:

Make sure to source the install/setup.bash file so that apriltag_msgs can see it when being built.

Building the apriltag_ros node

First, in order to detect AprilTags, we need to build the apriltag_ros node written by christianrauch. You can clone his repository by using this git repo:

To make his repo work with ROS2 Foxy, you will need to make a small change in the CMakeLists.txt file. Go to line 26 in that file and delete the apriltag:: token in the AprilTagNode apriltag::apriltag part.

Next, you'll want to save that file and run colcon build in the apriltag_ros folder. Once it is done building, you'll want to source the install/setup.bash file. Add this line to your .bashrc:

Creating a new package to concatenate camera information to each camera frame

In order to make the apriltag_ros node work, we need to make sure that camera info messages are being sent in sync with each camera frame published by the cam2image node. We have written an example node that does just that. You can download it here:

You will need to replace the matrices in the node file to match your camera calibration parameters. The source file is located at pypysub/py_pysub/publisher_member_function.py. Once you have done that, make sure to build and install the node and source the install/setup.bash file.

Running the code

To run the code, you'll need to run the following ROS nodes:

To use the package manager (apt) on the Demo image, you'll need to change your timezone.

First, you'll need to locate the correct timezone file at /usr/share/zoneinfo. There should be a folder for your country and a file in that folder for the closest city to you.

$ rm -f /etc/localtime
$ ln -sf /usr/share/zoneinfo/<country>/<city> /etc/localtime

For example, if you're in Central Time USA, you'd use the following commands:

$ rm -f /etc/localtime
$ ln -sf /usr/share/zoneinfo/America/Chicago /etc/localtime

Now, you can run sudo apt update and sudo apt upgrade to get your system up to date.

With OpenCV on NavQ, you will be able to harness a vast library of computer vision tools for use in HoverGames. OpenCV is installed out of the box on the HoverGames-BSP image and can be installed easily through the package manager on the HoverGames-Demo image. If you'd like to get a jump start on OpenCV, follow the guide below to create a program that detects red objects.

Quick Example

Let's go through a quick example of running OpenCV on the NavQ to identify a red object in an image taken on the Google Coral camera. This example will be written in Python and uses OpenCV.

Configuring Windows

Step 1 - Enable Mobile Hotspot

To enable Mobile Hotspot on Windows, go to Settings->Network & Internet->Mobile Hotspot. Next, you'll want to edit your mobile hotspot settings to set a password and SSID. Once you've done this, you can enable Mobile Hotspot. You can see a full configuration in the screenshot below.

Step 2 - Enable Port 5000/5600 in Firewall

By default, port 5000 or port 5600 is not open in the Windows firewall, so any UDP stream packets will be blocked. To enable this, go to your Windows search bar, and type "Firewall". Select "Windows Defender Firewall".

Once you open Windows Defender Firewall, you'll want to navigate to "Advanced Settings" from the menu on the left.

You will then be brought to a new window with Windows Firewall rules. To create a new rule for QGC streaming, you'll need to click "New Rule" on the right side.

You will be brought to a new window to add a rule. Select "Program" and click "Next".

At the next window, it will ask you to specify the program you are adding a rule for. Paste the following into that field and click "Next":

Once you've done this, you can click "Next" through the rest of the fields and you should be good to go.

Step 3 - Connect NavQ to new Mobile Hotspot

To connect your NavQ to your new Mobile Hotspot, follow the connecting to WiFi guide in the Gitbook here:

Step 4 - Stream to QGroundControl

Now you can stream to QGroundControl as you normally would. Follow the guide here:

Configuring Ubuntu

Step 1 - Enable Wifi Hotspot

To enable a WiFi hotspot in Ubuntu 20.04, you'll first need to go to Settings->WiFi. Then, at the top right, click the 3 dots button and select "Turn On Wi-Fi Hotspot...".

After you click that entry, this window will pop up. Enter a network name and password, and you should be good to go! Follow Steps 3 and 4 in the Windows section above to configure your NavQ.

MAVLink / MAVROS

The 8MMNavQ can control your HoverGames drone by communicating with the RDDRONE-FMUK66 over MAVROS. A UART cable will be included in the kit that connects the UART3 port on the 8MMNavQ to the TELEM2 port on the RDDRONE-FMUK66.

Prerequisites

Set up TELEM2 on the FMU

Connect to your FMU over USB and open QGroundControl. Navigate to Settings -> Parameters -> MAVLink and set these parameters:

Also, you'll need to make sure that the settings in Settings -> Parameters -> Serial look like this:

Offboard control guide

MAVROS Offboard node example

A coding guide for the ROS node we will be using is located at the link below.

This guide will help you install the ROS node outlined in the MAVROS Offboard Example.

Setting up your development environment

To start, you'll want to make sure that you have already set up a development environment for ROS. ROS has a guide on how to get a catkin workspace set up in the link below.

Once you've completed that tutorial, you'll maybe want to add an extra line to your ~/.bashrc so that your devel/setup.bash is always sourced when you open a new terminal:

This will ensure that your development environment is properly set up when you open a new shell.

Installing MAVROS specific packages

Follow the "binary installation" guide on the page below to install the necessary MAVROS packages from apt.

Creating a new package

To create our first ROS package, we will want to navigate to our catkin workspace's src folder and run the following command:

This command will create a new package folder named offb and will add the dependencies roscpp, mavros_msgs, and geometry_msgs to the 'CMakeLists.txt' and 'package.xml' files. Next, you'll want to take the code from the PX4 MAVROS example and create a file named offb_node.cpp in the src/ folder in the offb package. Your directory structure should now look like this:

Editing CMakeLists

In order to build your ROS package, you'll need to make some edits to CMakeLists.txt so the catkin build system knows where your source files are. Two edits need to be made.

The first edit is to add your executable to CMakeLists. Your executable should be named offb_node.cpp. Uncomment line 136 to add it:

The second edit is link your target libraries (roscpp, mavros_msgs, and geographic_msgs). Uncomment lines 149-151 to do so:

And that's all you need to do for now to set up your workspace!

Building your ROS node

To build your ROS node, return to the root of your catkin_ws/ directory and run:

Running your ROS node

To run our ROS node, we need to make sure that MAVROS is running. On the NavQ, run the following command:

This will start roscore and the mavros node with a pointer to the UART port /dev/ttymxc2 at a 921600 baud rate. To run the ROS node we created, run the following in an ssh terminal:

and your drone should take off to an altitude of 2 meters!

We have pages for several common software packages. Click the links below or follow the guide on the left of your screen.

ROS on NavQ

ROS on NavQ will allow you to interface with sensors, control your drone using MAVROS, and more. To get started, follow the install guide below and then continue to the next sections.

Install guide by OS

HoverGames-Demo image

To install ROS, you need to be on the Demo image. You can follow the guide for installing ROS Noetic Ninjemys at

HoverGames-BSP image

ROS Melodic is automatically installed on the HoverGames-BSP image. It includes MAVROS by default. You will need to do a little bit of setup, though, once you first boot your image.

Run the following commands to enable ROS on the HoverGames-BSP image:

You'll also want to download the following script and run it to install GPS geoids:

Now, you can continue with the ROS tutorials for setting up a build environment and installing your first package. We will go over this in the .

Taking a picture

To take a picture on your NavQ using GStreamer, run the following command:

To take video, you can run the following pipeline:

Gazebo is one of several simulators that work with PX4 and ROS.

Simulation is important in order to test code without risk of damaging real hardware. It can be critical in uncovering faults that would otherwise be very difficult to trigger. This is not a tutorial on Gazebo, but a list of some resources to get started.

• PX4.io Gazebo developer guide https://dev.px4.io/v1.9.0/en/simulation/gazebo.html

• Youtube videos e.g.

• Read about .

• Try out , which is a fun way to learn both Gazebo and ROS. (smile)

Please refer to the following pyeIQ documentation:

Note that eIQ support is only included on imx-image-full-imx8mpevk.wic pre-built image [1]. *** THIS IMAGE is only for 8M Plus!

Please take a look on switch_image application, we are using TFLite 2.1.0. This application offers a graphical interface for users to run an object classification demo using either CPU or NPU.

# pyeiq --run switch_image

We also have a TFLite example out of pyeIQ, please refer to instructions below. Details can be found on i.MX Linux User's Guide [2].

# cd /usr/bin/tensorflow-lite-2.1.0/examples

# ./label_image -m mobilenet_v1_1.0_224_quant.tflite -i grace_hopper.bmp -l labels.txt

The i.MX Linux User's Guide [2] also provides instructions on how to get our latest Linux BSP [1] up and running. *** NOTE FOR 8M Plus only!

[1]:

[2]:

Prerequisites

Devices required

In this guide, we need a few things:

1. NavQ Companion Computer mounted with Google Coral Camera attached

2. Laptop/Phone with QGroundControl Installed

3. Both NavQ and mobile device connected to the same WiFi network

Setting up QGroundControl

In QGroundControl, click the Q logo in the top left, and configure the video section as seen in the image below:

This will set up your QGroundControl instance to receive the UDP video stream from the NavQ.

Connecting your NavQ to your router and getting IPs

Follow the WiFi setup guide using connman in the Quick Start guide to connect your NavQ to the same router as your mobile device. You will need to use the serial console to do this. Once you have your NavQ connected, you can run ifconfig in the serial console to find the IP address of your NavQ.

You can SSH into the NavQ to run the GStreamer pipeline once you have the IP.

Running the GStreamer pipeline

With your NavQ on, SSH into it by using the IP address you noted when connected to the serial console. Once you're successfully SSHed in, you should note the IP address that you logged in from as seen here:

This is the IP of your computer that you should be sending the video stream to.

To run the GStreamer pipeline, run the following command:

Once you run that command, you should be able to see the video stream from your NavQ on QGroundControl!