Random thoughts on having the Ubuntu Server 21.10 running on top of Raspberry PI 3, and 23.04 running on Raspberry PI Zero 2 W.

Installation

• Raspberry PI Ubuntu Page
• Tutorial on how to install Ubuntu server on your RPI

Download the appropriate image from the download page, flash it according to the tutorial, and boot it. I’m running aarch64 Ubuntu Server on my Raspberry PI 3 with 1GB of RAM, however there’s no real advantage over aarch32 and aarch32 takes up less disk space and memory, therefore I advise you to go with aarch32.

You can either use the rpi-imager tool, or flash the microsd card from cmdline:

xzcat ubuntu-23.04-preinstalled-server-armhf+raspi.img.xz |sudo dd of=/dev/XYZ bs=1M conv=fsync status=progress

Ubuntu will resize the filesystem automatically on first boot, to span over the entire microsd card.

I’d recommend not to go with Ubuntu Desktop - Raspberry PI 3 is simply not powerful enough / doesn’t have enough RAM to run Ubuntu Desktop properly - both Gnome Shell and KDE are sluggish as hell.

The default username/password is ubuntu/ubuntu, but you can only log in after cloud-init configured the user. Just wait a bit for a line that says cloud-init v xyz finished at xyz.

Networking

The network may be down since netplan refers to the eth0 interface, while you will most probably have something starting with enx7...... List your network interfaces with ip link show, then run sudo dhclient enx7...... to configure the interface for your network.

Upgrading & cleaning up

You can remove snapd:

$ sudo apt autoremove --purge snapd

Then upgrade the system:

$ sudo apt update
$ sudo apt -V dist-upgrade

If you’ll get an error during update that “Release file not valid yet”, set the timezone correctly, using timedatectl:

$ timedatectl
$ sudo timedatectl set-timezone Europe/Helsinki

Wifi

Using netplan with ubuntu works for me well: when configured properly, Raspberry PI will automatically connect to wifi on boot and you can simply ssh to it.

I have the following file /etc/netplan/00-wifi.yaml:

network:
  wifis:
    wlan0:
      dhcp4: true
      optional: true
      access-points:
        "<YOUR_AP_NAME>":
          password: "<YOUR_AP_PASSWORD>"
  version: 2
  renderer: networkd

Make sure you have the netplan.io package installed. Then, run sudo netplan --debug apply and your wifi should be up - you can verify that by running ifconfig -a.

Also see Ubuntu Netplan no NetworkManager.

Note that RPI may not see 5G networks, only 2,5G ones. Run iwlist wlan0 scan to see access points available to RPI.

Controlling GPIO

• Python: see gpiozero
• Kotlin: see ktgpio-example-app