RPi Getting started

The single-board computer has gained a lot of fame in recent years and is used in a variety of projects. This mini-computer can be used in a great variety of ways, especially because of its size and features. Especially for experimental set-ups or software and hardware tests, the quick set-up and dismantling is very advantageous. This article is all about setting up and getting started with this computer.

The models

Since the first model came on the market in 2012 and the credit card-sized computer wowed the world, there is now a wider range of Pis. Each Pi has a screen connector, audio outputs, LAN and USB, as well as GPIO (general purpose input/output) pins. Some boards also have a ribbon connector for a display and a camera. With each new model, the computer’s performance increases and adds small innovations. The Raspberry Pi 4, for example, has Gigabit Lan, Wlan on two frequency bands and Bluetooth 5.0, so it is already equipped for many communication paths, whereas the Raspberry Pi 1 and 2 only had LAN. The following table provides a rough overview of the equipment:

| | RPi 4B | RPi 3B+ | RPi 3B | RPi 2B | RPi 1 | | ----------------- | --------------------------- | --------------------------------- | --------------------------- | ---------------------- | ---------------------- | | size | 85.6 × 56mm | 85.6 × 56mm | 85.6 × 56mm | 85.6 × 56mm | 85.6 × 56mm | | SOC | BCM2711 | BCM2837 | BCM2836 | BCM2835 | | CPU | ARM Cortex-A72 (ARMv8-A) | ARM Cortex-A53 (ARMv8-A) | ARM Cortex-A53 (ARMv8-A) | ARM Cortex-A7 (ARMv7) | ARM1176JZF-S | | CPU Cores | 4 | 4 | 4 | 1 | | CPU clock | 4x 1500 MHz | 4x 1400 MHz | 4x 1200 MHz | 4x 900 MHz | 1x 700 MHz | | RAM | 1024 MB, 2048 MB or 4096 MB | 1024 MB | 1024 MB | 512 MB | | USB | 2x USB3.0, 2x USB2.0 | 4x USB2.0 | 4x USB2.0 | 4x USB2.0 | | Video | 2x Micro-HDMI | 1x HDMI | 1x HDMI | 1x HDMI | | Audio | HDMI (digital) | 3.5mm jacks, HDMI (digital) | 3.5mm jacks, HDMI (digital) | 3.5mm jacks | | Network | 10/100/1000 MBit | 10/100/1000 MBit (max. 300Mbit/s) | 10/100 MBit | 10/100 MBit | | Wlan | 2.4/5 GHz WLAN ac | 2.4/5 GHz WLAN ac | 2.4 GHz WLAN b/g/n | no | no | | Bluetooth | 5.0 | 4.2 | no | no | | GPIO | 40 pins | 40 pins | 40 pins | 26 pins | | Power consumption | max. 7.6 W | max. 7 W | max. 4 W | max. 4 W | max. 4 W | | Power Source | 5V USB-C, min. 3.0 A | 5V Micro USB, min. 2.5 A | 5V Micro USB, min. 2.5 A | 5V Micro USB, min. 2 A | 5V Micro USB, min. 2 A |

Different operating systems are available for all models and projects of various types are possible. For more computing power or high connectivity, the newer models are recommended; for small projects and tinkering, an older model is usually sufficient.

The right operating system

For each application and specialisation, there is already one or two operating systems designed for it. RetroPi is recommended for retro gaming on the TV, LibreElec for a film library and Raspbian for a home computer for work. In the end, everyone has to find out for themselves which operating system is the right one. In another article, we listed the most popular and best operating systems for Raspberry Pis and explained what they can be used for.

For this article, we will use Ubuntu Server as the operating system.

Getting started with the Raspberry Pi

Writing the operating system to the SD card

Easier than ever for many operating systems is writing the operating system to the SD card. Using the Rpi Imager 🔗 tool, a wide range of operating systems can be selected, downloaded and installed directly. For this example, we install Ubuntu Server 32Bit on a RaspberryPi 3B+.

Preparation before the first start

Before the first start, some settings can already be made. This includes the wifi connection: to do this, we open the file ‘network-config’ and add the network point:

wifis:
  wlan0:
  dhcp4: true
  optional: true
  access-points:
    <wifi network name>:
      password: "<wifi password>"

The network name must be in inverted commas. If no connection is found at the first start, simply reboot with sudo reboot.

the first start

Insert the SD card into the Raspberry Pi. If you are using an HDMI screen and USB keyboard, make sure they are connected before powering up. After the boot process the login screen appears, with “ubuntu” as password and login ID you can log in directly. Welcome to the first user account on your new Ubuntu. From here on you can install a graphical user interface or stay in the terminal.

Another variant is the ‘headless’ mode. Here, no peripherals such as a screen or input devices are connected to the computer and it is usually used for servers. The computer can then be controlled and managed via a (relatively) secure connection (in another article we will show how to strengthen this secure connection). This offers the advantage of needing fewer computer peripherals and being able to operate several servers simultaneously from one computer without changing the workstation or connections. This mode is already provided for in the Ubuntu Server version and is ready to start immediately. After inserting the SD card and connecting it to the router via LAN, the Raspberry can be connected to the power supply. To access it now, we use SSH (a communication protocol between computers) and need the IP address of our Raspberry in the local network. We can find the IP address via our terminal:

arp -na | grep -i "b8:27:eb" #rpi 4 has "dc:a6:32"

If the command is not available on your system, install it with the net-tools package after: sudo apt install net-tools and use the command again. Windows can also use arp, the command here is: arp -a | findstr b8-27-eb. The return looks something like this ? (xx.xx.xx.x) at b8:27:eb:yy:yy:yy [ether] on wlp2s0, where the x is the IP address on the local network. We will use this again in a moment. If no address is found, it is possible that the Raspberry has not yet been able to log on to the network. Just try again after a few minutes or restart the Raspberry in an emergency.

In Ubuntu and Mac OS an SSH client is installed by default, for Windows this must be installed later. You can then call SSH directly in a terminal:

ssh ubuntu@<RaspberryPi IP address>

The connection must then be confirmed by typing ‘yes’. The requested password is also ‘ubuntu’. The successful connection via SSH can be recognised in the terminal by the updated user name and the computer address. It is possible that Ubuntu Server uses an alternative algorithm, e.g. diffie-hellmann; you can use this simply with ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 <IP address>.

After the first start, it is recommended to change the password to protect access from attackers. Ubuntu even forces this on the first start. Then download the latest updates and start having fun with the new server.

sudo apt update && sudo apt upgrade -y

More tips to make your RaspberryPi (and other computers) more secure can be found in another article of ours.

Install a desktop environment

In the headless variant, the server only has a terminal but no graphical user interface. If you want to use the Raspberry as a computer with a screen, there are packages for installing an interface. Two lightweight ones are xubuntu or lubuntu:

sudo apt install xubuntu-desktop #choose only one
sudo apt install lubuntu-desktop

After the installation, reboot and you will be taken directly to the graphical user interface (reboot: sudo reboot).

All information about RaspberryPis and its community can also be found at RaspberryPi.org 🔗.