NanoPi R3S LTS Setup Instructions

For the hardware, if you have no other preference, I would go with:

For the operating system image and board-specific installation information, see:

The instructions for flashing the operating system to eMMC are on the same page. See:

Section 4.4.3 - Install OS to eMMC

Once the operating system is installed and the system has booted, you should be able to connect a monitor and get a command shell.

Basic Setup

First update the system:

sudo apt update
sudo apt upgrade -y

Install Java 8:

sudo apt install openjdk-8-jdk

I would also install a lightweight windowing system:

sudo apt install lxqt lightdm

To start the window manager manually:

sudo systemctl start lightdm

You can also configure the graphical desktop to start automatically at boot, as described below.

sudo apt update
sudo apt upgrade -y

TransSECS currently requires Java 8 (or will run in Java 11)

On a Debian-based Armbian installation:

sudo apt install openjdk-8-jdk

Verify the installation:

java -version

You should see output similar to:

openjdk version "1.8.0_xxx"

If multiple Java versions are installed, select Java 8 as the default:

sudo update-alternatives --config java

Install the LXQt desktop and LightDM login manager:

sudo apt install lxqt lightdm

During installation, if prompted to select a display manager, choose:

lightdm

To start the graphical desktop automatically whenever the NanoPi boots:

sudo systemctl enable lightdm
sudo systemctl set-default graphical.target
sudo reboot

After reboot, the system should display the LXQt login screen.

If the system will normally operate without a monitor, you can disable the graphical desktop:

sudo systemctl disable lightdm
sudo systemctl set-default multi-user.target
sudo reboot

After reboot, the system will start in command-line mode only.

If the desktop is normally disabled but you need it temporarily for maintenance:

sudo systemctl start lightdm

This launches the graphical login screen without changing the boot configuration.

To stop the graphical desktop and return to command-line operation:

sudo systemctl stop lightdm