Common Software Tasks

The various subheadings of this document are linked in other pages. This page is meant as a reference for commonly performed tasks.

Password-Free Access

For password free access to the Orin, follow these steps:

1. Ensure that you have an SSH key in ~/.ssh
   1. If not, run ssh-keygen -t ed25519 -C <yourCommentHere>
2. With the USB connected, run ssh-copy-id lis@192.168.55.1
3. Make sure that the ssh-agent is on: eval `ssh-agent`
4. Add your key to the agent: ssh-add
5. Ensure that you can access the device without a password: ssh lis@192.168.55.1

Wi-Fi Setup

SSH into the Orin. The following is a reference for commands that you can use with nmcli:

To see available Wi-Fi networks: nmcli device wifi list

To connect to a network with simple auth (open or WPA2/WPA3 password): sudo nmtui -> Activate Connection, or:

sudo nmcli connection add type wifi \ 
con-name "NetworkName" \
ssid "SSID" \
wifi-sec.psk "password" \
wifi-sec.key-mgmt "wpa-psk"

To connect to a more complicated network (eduroam/epfl):

sudo nmcli connection add type wifi \
con-name "epfl" \
ssid "epfl" \
wifi-sec.key-mgmt wpa-eap \
802-1x.eap ttls \
802-1x.phase2-auth mschapv2 \
802-1x.identity "YourUsername" \
802-1x.password "YourPassword" \
802-11-wireless.bssid "AA:BB:CC:DD:EE:FF"

Replace YourUsername, YourPassword with your GASPAR credentials. You can find the bssid of your local router by nmcli device wifi list. Use that instead of AA:BB:CC:DD:EE:FF.

To activate a connection, you can either use sudo nmtui, or:

nmcli con up <Name>

Get IP of Computer

You can get the internet protocol address of a Linux computer by running ifconfig and looking for the four numbers after inet under the interface that you care about. Wireless interfaces typically begin with w, and ethernet interfaces typically begin with e.

On most networks, you can usually use hostname.local in place of the IP address if the two computers are on the same network. Replace hostname with the hostname of the computer. You can get the hostname by running: hostname or hostnamectl on the computer.

Wireless Connection to QGroundControl

This is done with mavproxy mavproxy.py --master="/dev/ttyACM0" --baudrate 115200 --out="udp:<ipofhost>:14550".

Rescue Unreachable Device

If you do not know the IP address of a drone, you can try these steps to find it's IP:

1. Try restarting everything first.
2. Try running avahi-resolve -n hostname.local while on the same network.
3. Try running avahi-resolve -n hostname-2.local. Sometimes, the original hostname gets reserved and this becomes a fallback. If this works, you can run avahi-publish in the background with the original hostname to force it to work.
4. Connect to the recovery port using a USB-C cable. You should be able to SSH into the device at 192.168.55.1 and use ifconfig to find the IP.
   1. Then, you can use avahi-resolve -a <ip> to find the mDNS hostname.

VNC/Remote Desktop Setup

On the host computer, go to terminal and type gvncviewer nxt1.local where nxt1 is the hostname of the Orin on which is on the same network as the host computer. Then input the password 'orin'. This will allow you do remote desktop into the Orin. You can also replace nxt1.local with the full IP address of the orin e.g. gvncviewer 192.168.55.1.

ROS Package Management

The ansible setup automatically installs convenient bash aliases for managing the ROS packages systemd service on both host computers and drones. These aliases simplify common systemctl operations:

Available Aliases

• ros_status - Check the status of the ros_packages service (systemctl --user status ros_packages)
• ros_start - Start the ros_packages service (systemctl --user start ros_packages)
• ros_stop - Stop the ros_packages service (systemctl --user stop ros_packages)
• ros_restart - Restart the ros_packages service (systemctl --user restart ros_packages)

Log Viewing Function

• ros_logs [arguments] - View logs from the ros_packages service with optional journalctl arguments

Examples:

ros_logs                    # View all logs
ros_logs -f                 # Follow logs in real-time
ros_logs --this-boot        # Show logs from current boot only
ros_logs -n 50              # Show last 50 lines
ros_logs --since "1 hour ago"  # Show logs from last hour

Updating Drone Software

Use the drones_update.yml playbook to update and rebuild the ROS packages on drones:

cd ansible/

# Regular update (incremental build)
ansible-playbook -i inventory.ini drones_update.yml

# Clean build (removes build/ and install/ directories first)
ansible-playbook -i inventory.ini drones_update.yml -e clean_build=true

The clean build option is useful when: - Switching between branches with significant changes - Resolving build cache issues - After updating message definitions or package dependencies - Troubleshooting package discovery problems

Data Logging with ROS Bag

The SwarmNXT system automatically records flight data using the standard ROS 2 bag recording functionality. This section covers how to configure and use the logging system.

Logging Overview

The system uses ros2 bag record integrated into the drone launch files to automatically capture: - Drone planner commands - Custom application topics

All data is stored in MCAP format for efficient storage and playback.

Configuring Logged Topics

Topics to log are configured in the Ansible inventory file ansible/group_vars/all:

# Configure which topics to record
drone_rosbag_topics: 
  - "/{{ ns }}/*"                    # All topics in drone namespace
  - "/agent_[0-9]+/*"                # All topics in/out by the planner/mapper
  - "/fmu/*"                         # All topics in/out of the FC
  - "/depth/*"                       # All topics in/out of depth estimator
  - "/tf"                            # Transforms

Recorded Data Location

Bag files are automatically saved to: - Location: $ROS_LOG_DIR/bag/ on each drone - Format: MCAP (.mcap files) - Size limit: 1 GiB per file (automatically splits)

Viewing Recorded Data

After running the post-flight script, you can open the bags with Foxglove or just run them from the terminal.

Common Issues

Ansible Stuck

There are a few reasons that ansible can be stuck. Sometimes, the wrong BECOME password is provided. This may result in a long time without any feedback.

If the password is correct, it is possible that the host or target went to sleep or shutdown in the middle of a play. This can result in Ansible trying to use a dead ssh session. In this case, try deleting the ~/.ansible/cp folder and restarting the play.