InstallRPI.md

Install Ubuntu 20.04 Server for the companion computer

Build from our Raspberry Pi images

There are several 2 ways to build raspberry pi system. Easiest of courece is to download the image that we are provided.

We are tested and provided several images (https://drive.google.com/drive/folders/1ff6Cl5y6kWvpjLPnML8qoepN1H--mvBu?usp=share_link):

• Raspberry Pi Model 4B 4G RAM
• Raspberry Pi Model 3B

Build from Source(optional)

Install the image ubuntu 20.04 server for raspberry

https://cdimage.ubuntu.com/releases/focal/release/

To connect to local wifi network run:

sudo nano /etc/netplan/50-cloud-init.yaml

add this line to the file:

wifis:
  wlan0:
    optional: true
    access-points:
        "your-ssid":
            password: "pass"
    dhcp4: true

After this, open terminal and note your IP address. The the setting can be modified:

wifis:
  wlan0:
    optional: true
    dhcp4: false
    dhcp6: false
    addresses: ["your-IP-address"/24]
    nameservers:
      addresses: [10.11.12.2]
    access-points:
        "your-ssid":
            password: "pass"
    routes:
      - to: default
        via: 10.100.190.1

where 10.11.12.2 is your DNS server IP, and 10.100.190.1 is your router IP. The yaml should look like this:

We should check the sintax for the errors

sudo netplan -debug generate

To connect to desktop with Ethernet cable:

Both desktop and Raspberry Pi should have IP adresses from the range 169.254.x.x to be ready to connect via ssh. You can verify IP adresses with this commands: for Windows

ipconfig

and for Linux (may require net-tools to be installed)

ifconfig -a

other options:

ip a
ip addr show
hostname -I

We need to mofify terminal UI for the colorful visualization:

ls -la ~/ | more
 nano ~/.bashrc

uncomment the line:

force_color_prompt=yes

press "ctrl + x", press "y", press "enter", write in terminal: exit

Encrease swap file:

See this instructions for the details https://www.digitalocean.com/community/tutorials/how-to-add-swap-space-on-ubuntu-20-04

Restart the device

sudo reboot

SSH control

Install the Putty software to your desktop https://www.putty.org/

Connect to ssh with IP: 192.168.1.6

Install ROS

sudo apt update

sudo apt install git python3-pip python3-schedule i2c-tools python3-smbus -y

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/src
git clone https://github.com/TPODAvia/ROS1-installation.git
chmod +x ROS1-installation/ROS_server.sh
sudo ./ROS1-installation/ROS_server.sh

echo "source /opt/ros/noetic/setup.bash" >> ~/.bashrc
source ~/.bashrc
source /opt/ros/noetic/setup.bash
sudo apt install xterm pi-bluetooth -y
sudo apt install build-essential python3-rosdep ros-noetic-hector-slam libpcl1 ros-noetic-octomap-* -y
# sudo apt-get install ros-noetic-hector-slam -y
# sudo apt install libpcl1 ros-noetic-octomap-* -y

Enable I2C connection

sudo nano /lib/udev/rules.d/60-i2c-tools.rules

Change Mode from "0660" to "0666":

KERNEL=="i2c-[1-9]*", GROUP="i2c", MODE="0666"

Install YOLOv8 dependencies

sudo apt-get install python3-scipy ros-noetic-vision-msgs ros-noetic-geometry-msgs -y
# sudo apt-get install ros-noetic-vision-msgs -y
# sudo apt-get install ros-noetic-geometry-msgs -y

Install the workspace

cd ~/catkin_ws
catkin_make
echo "source ~/catkin_ws/devel/setup.bash" >> ~/.bashrc
source ~/.bashrc

cd ~/catkin_ws/src

git clone https://github.com/TPODAvia/yolov8_ros.git
git clone https://github.com/okalachev/vl53l1x_ros
git clone https://github.com/machinekoder/ar_track_alvar.git -b noetic-devel

git init
git remote add origin https://github.com/TPODAvia/PX4-Autonomous-Vehicle.git
git pull origin main

cd ~/catkin_ws
source /opt/ros/noetic/setup.bash
sudo rosdep init

Now we need to delete gazebo-related package because it's not neeeded here

sudo rm -r src/px4_sim
sudo rm -r src/world_sim
sudo rm -r src/mavros_humantracking

rosdep update
rosdep install --from-paths src --ignore-src -y

sudo /usr/bin/python3 -m pip install -r ~/catkin_ws/src/requirements.txt
sudo /usr/bin/python3 -m pip install -r ~/catkin_ws/src/yolov8_ros/requirements.txt

cd ~/catkin_ws
source devel/setup.bash
catkin_make -j1

Install QGroundControl

cd
sudo /opt/ros/noetic/lib/mavros/install_geographiclib_datasets.sh

WIFI setup

cd ~/catkin_ws/src/swarms/
sudo wifi-hotspot.sh

I2C communication setup

Setting 9250 IMU module with I2C

Flash Arduino via ssh

Setting Raspberry Pi with Arduino

Custom image building for the Ubuntu Server

For Linux users there are really simple instructions on the internet how to do it but for Windows users there are some "hacks" how we can create an image backup for our companion computer

Go to the cmd and type:

"C:\Program Files\Oracle\VirtualBox\VBoxManage" internalcommands createrawvmdk -filename "c:/Hard Disks/sdcard.vmdk" -rawdisk "\\.\PHYSICALDRIVE1"

Go to Ubuntu: install GParted

sudo apt install gparted

Resize image there

Switch back to Windows and install "win32 disk imager". It's a simple way to create backup file.

Remember to check "Read Only Allocated Partitions"

Delete disk location

To delete the link to an SD card in VirtualBox, you can follow these steps:

• Open the VirtualBox Disk Manager.

• Locate the sdcard.vmdk file in the list.

• Select the sdcard.vmdk file and click on the "Remove" or "Delete" button.

From cmd excecute this line of code:

"C:\Program Files\Oracle\VirtualBox\VBoxManage" closemedium "C:\Hard Disks\sdcard.vmdk" --delete

Always On mode

To disable the sleep mode and allow automatic login in Ubuntu using the terminal, follow the steps below:

1. Disable Sleep Mode

To disable the sleep mode in Ubuntu, you can use the systemctl command to mask the sleep, suspend, hibernate, and hybrid-sleep targets. This essentially links these unit files to /dev/null, making it impossible for the system to start them Source 2.

You can execute the following command:

sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target

Keep in mind that this command will completely disable sleep mode, meaning your system will stay awake indefinitely until you manually put it to sleep or shut it down.

2. Enable Automatic Login

To enable automatic login, you'll need to edit the custom.conf file in the /etc/gdm3/ directory. Here is how you can do it:

First, open the file using a text editor such as nano.

sudo nano /etc/gdm3/custom.conf

Find the section in the file labeled [daemon]. In this section, uncomment (or add if it's not there) the line AutomaticLoginEnable=true and the line AutomaticLogin=[your username], replacing [your username] with your actual username.

Here is how it should look:

[daemon]
AutomaticLoginEnable=true
AutomaticLogin=john_doe

After making the changes, press Ctrl+X to exit and Y to save the changes. Then, restart your system for the changes to take effect.

Please note that enabling automatic login can pose a security risk as anyone who can access your computer will be able to turn it on and have immediate access to your files and data.

3. Handle Lid Close Action

In some cases, you might want to change the action that Ubuntu takes when the laptop lid is closed. To do this, you can edit the /etc/systemd/logind.conf file Source 9.

Open the file using a text editor:

sudo nano /etc/systemd/logind.conf

Find the line that starts with #HandleLidSwitch=suspend and change it to HandleLidSwitch=ignore. This will make Ubuntu do nothing when the laptop lid is closed.

Here is how it should look:

HandleLidSwitch=ignore

To prevent Ubuntu from going into suspend mode and turning on the lock screen, you can use the following steps:

4. Disable Automatic Lock Screen

To disable the automatic lock screen, you need to change the settings of the GNOME desktop. You can do this using the gsettings command. The following command will disable the lock screen:

gsettings set org.gnome.desktop.session idle-delay 0
gsettings set org.gnome.desktop.screensaver lock-enabled false

This command will prevent the lock screen from appearing due to inactivity Source 2.

5. Disable Lock Screen Upon Suspend

In addition to disabling the automatic lock screen, you may also want to disable the lock screen that appears after your system wakes up from suspend. You can do this with the following gsettings command:

gsettings set org.gnome.desktop.screensaver ubuntu-lock-on-suspend false

This command will prevent the lock screen from appearing after suspend Source 2.

After making the change, save and close the file, then restart the systemd-logind service by running:

sudo reboot

Please keep in mind that these changes should be made carefully as they can significantly alter the behavior of your system. Always make sure to backup any files you edit in case you need to revert the changes. Again, please note that disabling the lock screen and suspend mode can pose a security risk. Anyone with access to your computer will be able to use it without having to enter a password. Please use these commands responsibly.

6. Watchdog

To enable the watchdog timer on your Raspberry Pi running Ubuntu 22.04, you can follow the steps below:

1. Activate the hardware watchdog on your Raspberry Pi. In your config.txt file, add the following line to enable the watchdog:

dtparam=watchdog=on

You can edit this file using the nano editor with the command sudo nano /boot/config.txt, then add the line above at the end of the file and save it Source 7.

2. Reboot your Raspberry Pi. After the reboot, you can check if the watchdog is enabled by running the command ls -al /dev/watchdog*. You should see output similar to this:

crw------- 1 root root  10, 130 May 19 07:09 /dev/watchdog
crw------- 1 root root 253,   0 May 19 07:09 /dev/watchdog0

This indicates that the watchdog is enabled Source 7.

3. Install the watchdog software package with the command sudo apt-get install watchdog Source 1.

4. Configure the watchdog package. Edit the configuration file /etc/watchdog.conf and uncomment or add the following lines:

max-load-1 = 24
min-memory = 1
watchdog-device = /dev/watchdog
watchdog-timeout=15

You can edit this file using the nano editor with the command sudo nano /etc/watchdog.conf, then make the changes and save the file Source 7.

5. Start the watchdog service with the command sudo systemctl start watchdog and enable it to start at boot with the command sudo systemctl enable watchdog Source 7.

6. Verify that the watchdog service is running with the command sudo systemctl status watchdog. If it's running correctly, you should see output indicating that the service is active Source 1.

With these steps, you should have successfully enabled the watchdog timer on your Raspberry Pi running Ubuntu 22.04. The watchdog timer will help to automatically reboot the system in case it freezes.

Ubuntu Server uses Netplan to manage its connections.

To create an access point using Netplan, you can do the following:

1. Install Network Manager

sudo apt update
sudo apt install network-manager

2. Disable cloud-init

sudo bash -c "echo 'network: {config: disabled}' > /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg"

3. Create a Netplan configuration

sudo nano /etc/netplan/50-cloud-init.yaml

Then add the following configuration:

network:
  version: 2
  renderer: NetworkManager
  ethernets:
    eth0:
      dhcp4: true
      optional: true
  wifis:
    wlan0:
      dhcp4: true
      optional: true
      access-points:
        "Raspberry":
          password: "12345678"
          mode: ap
        "Additional_WIFI_Name_1":
          password: "12345678"
        "Additional_WIFI_Name_2":
          password: "12345678"

You can change the access point name "Raspberry" and the password to your liking.

Then save the file using CTRL+X.

4. Apply the Netplan configuration

Finally, use use the following commands to apply your new configuration:

sudo netplan generate
sudo netplan apply
sudo reboot

A new wireless access point should be created. It has DHCP and DNS enabled by default, and if the Pi has internet access over Ethernet, it'll be shared over the WiFi hotspot as well.

5. To enable/disable Wifi

Run this command:

The command template is look like this:

sudo nmcli c up/down your_wifi_name

This command is used to activate a hotspot connection:

sudo nmcli c up netplan-wlan0-Raspberry

To switch to others WiFi connection - run this

sudo nmcli c up Additional_WIFI_Name_1

sudo nmcli c down Additional_WIFI_Name_1

6. To display a list of visible Wi-Fi networks:

nmcli d wifi list

nmcli connection show netplan-wlan0-Raspberry

7. Bash script

The connections control can be wrapped to the bash script. The example are provided in the bash folder.