The hardware being used for this demonstration is the PX4 Vision Autonomy Development Kit. This platform provides a ready to fly quadcopter with a pixhawk 4 flight controller and an on board UP Core companion computer. For the purposes of the demonstration some additional setup is required which is detailed in this document.
The only hardware setup required is to install the TBS Crossfire Nano Rx.
Solder Header pins to ground, 5V and CH1 pins.
Connect Rx header pins to port marked DSM/SBUS RC on Pixhawk 4 with included cable.
Bind Rx to radio.
Run crossfire lua script on radio, select Nano Rx and change CH1 to sbus.
WiFi Telemetry Setup
By default the PX4 Vision Autonomy Devlopment Kit comes with an ESP8266 WiFi Telemetry module which is set to access point mode. This will broadcast a network which the ground station can connect to to receive telemetry. For the purposes of the demonstration the ESP8266 module needs to be in station mode instead. When in station mode the module will connect to an existing wifi network and telemetry can be passed to the ground control station through the network. This means one ground station can receive telemetry from multiple drones through the same WiFi network. Though QGroundcontrol offers a setup inteface for the module it is not functional, therefore the browser setup interface must be used.
Connect to the wireless access point created by the ESP8266 module, in the case of the PX4 Vision Autonomy Development Kit the SSID and password are both pixhawk4.
Navigate to http://192.168.4.1/ in a browser.
click on ‘Setup’.
Set the ‘WiFi Mode’ to ‘Station’, set the ‘WiFi Channel’ to 6, enter the SSID and password of the existing wifi network into ‘Station SSID’ and ‘Station Password’, all other settings can be left as default. Save these settings and reboot the drone.
The WiFi Module should now reboot in station mode and connect to the existing network, telemetry should now be visible in port 14550 in QGroundcontrol.
Assign a static IP to the WiFi Telemetry module following the instructions in the Setting up the Local Network page. The setup page can now be accessed by navigating to the new static IP in the browser.
Both the Pixhawk and the UP Core companion computer require some software setup for the demonstration.
Ubuntu Installation on UP Core
Follow the tutorial on the Ubuntu website to create a bootable Ubuntu 20.4 LTS USB Stick.
Connect a keyboard, mouse and monitor to the UP Core and insert the USB stick then connect the computer to power.
The computer will boot and give the option to try Ubuntu or install it, select install and follow the on screen setup process. Make sure to select ‘Minimal Installation’ and ‘Erase disk and install Ubuntu’.
Enabling use of the serial port in Ubuntu (IMPORTANT)
By default Ubuntu includes a modem manager which blocks the use of the serial port to communicate with the Pixhawk. This must be removed with the following terminal commands.
sudo usermod -a -G dialout $USER sudo apt-get remove modemmanager -y
By default ssh is not installed on Ubuntu 20.4 LTS. In order to avoid the need for a monitor keyboard and mouse for each drone in the swarm during development it can be installed and enabled with the following terminal commands.
sudo apt update sudo apt install openssh-server sudo ufw allow ssh