Useful Support Software

These are support libraries we run on IRL drones to make life easier. E.g., simplify ssh, file access, video streaming, etc. Note that all of these are set up by default if you use the quickstart script. If instead you want to manually install them, instructions follow.

mDNS

This will make it so on any connected network, your drone hostname shows up as drone.local instead of requiring a specific IP.

sudo apt update
sudo apt install avahi-daemon avahi-utils
sudo hostnamectl set-hostname drone

And so that it starts on boot:

sudo systemctl enable avahi-daemon
sudo systemctl start avahi-daemon

From here on, instructions will assume the drone can be pinged/ssh'd at decco@drone.local. If you skip this step, replace this with the usual decco@ipaddr.

Tip

If you plan to run the frontend and want to access it easily from multiple devices, you can do the same thing on your laptop, eg name it frontend.local so anyone can pull up the drone interface.

Video stream

We use the mediamtx video server so we can easily switch between RTSP, WebRTC, HLS, etc.

Tip

If you use the open drone frontend, after setup, this stream will be automatically available in the drone interface.

Download and extract this release:

cd ~/src
mkdir video
cd video
wget https://github.com/bluenviron/mediamtx/releases/download/v1.8.1/mediamtx_v1.8.1_linux_arm64v8.tar.gz
tar -xf mediamtx_v1.8.1_linux_arm64v8.tar.gz

Change the RTSP params:

cd ~/src/video
nano mediamtx.yml

Scroll to the end and change the paths section to read:

paths:
  camera:
    runOnDemand: ffmpeg -f v4l2 -i my_video_device -pix_fmt yuv420p -c:v libx264 -preset ultrafast -tune zerolatency -b:v 1M -f rtsp rtsp://localhost:$RTSP_PORT/$MTX_PATH
    runOnDemandRestart: yes

Replace my_video_device as needed e.g. with /dev/video0/ or preferably, a symlink. It's better if the device is symlinked in case video devices get reordered on boot. Default devices (mapir, immervision, and seek cameras) get symlinks created by running the quickstart script. If adding your own device, create a symlink by:

lsusb

Output should be e.g.

Bus 001 Device 004: ID 0603:8612 Novatek Microelectronics Corp. MAPIR

Make a file drone-99.rules and copy this into it:

ACTION=="add", SUBSYSTEM=="video4linux", ATTRS{idVendor}=="0603", ATTRS{idProduct}=="8612", ATTR{index}=="0", SYMLINK+="mapir"

The symlink arg can be whatever you choose. Then create the symlink with:

sudo cp drone-99.rules /etc/udev/rules.d/
sudo udevadm control --reload-rules && sudo udevadm trigger

To test if the stream is working, run with:

./mediamtx

After confirming, set up a systemd service so the stream starts automatically on boot.

Start on Boot

cd ~/src/video
sudo cp mediamtx /usr/local/bin/
sudo cp mediamtx.yml /usr/local/etc/
sudo nano /etc/systemd/system/mediamtx.service

In the service file, paste:

[Unit]
Description=Drone Video Stream
Wants=network.target
[Service]
ExecStart=/usr/local/bin/mediamtx /usr/local/etc/mediamtx.yml
[Install]
WantedBy=multi-user.target

Now enable the service:

sudo systemctl daemon-reload
sudo systemctl enable mediamtx.service
sudo systemctl start mediamtx.service

View Stream

The easiest place to test is in our frontend, which automatically connects and displays the stream. For an alternate, you can use QGroundControl. In Application Settings, enable the video stream and set the RTSP stream to rtsp://drone.local:8554/camera like so:

File Manager

We provide a file manager service that enables easy file transfer from flight data (videos, pointclouds, logs, ROS2 mcaps). This is a service that runs on the drone but can be accessed through the browser on a device on the same network. Setup using the standalone script:

cd ~/src/open-drone-core
./scripts/steps/07-file-manager.sh

The files are then accessible at http://drone.local:9999. It should look like: