====== NanoPi R3S LTS Setup Instructions ======

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

[[https://armbian.com/boards/nanopi-r3s-lts|NanoPi R3S LTS - Armbian]]

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

[[https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R3S|FriendlyELEC NanoPi R3S Wiki]]

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:

<code bash>
sudo apt update
sudo apt upgrade -y
</code>

Install Java 8:

<code bash>
sudo apt install openjdk-8-jdk
</code>

I would also install a lightweight windowing system:

<code bash>
sudo apt install lxqt lightdm
</code>

To start the window manager manually:

<code bash>
sudo systemctl start lightdm
</code>

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

===== 1. Update the System =====

<code bash>
sudo apt update
sudo apt upgrade -y
</code>

===== 2. Install Java 8 =====

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

On a Debian-based Armbian installation:

<code bash>
sudo apt install openjdk-8-jdk
</code>

Verify the installation:

<code bash>
java -version
</code>

You should see output similar to:

<code>
openjdk version "1.8.0_xxx"
</code>

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

<code bash>
sudo update-alternatives --config java
</code>

===== 3. Install LXQt =====

Install the LXQt desktop and LightDM login manager:

<code bash>
sudo apt install lxqt lightdm
</code>

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

<code>
lightdm
</code>

===== 4. Enable the Desktop at Boot =====

To start the graphical desktop automatically whenever the NanoPi boots:

<code bash>
sudo systemctl enable lightdm
sudo systemctl set-default graphical.target
sudo reboot
</code>

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

===== 5. Disable the Desktop for Headless Production Mode =====

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

<code bash>
sudo systemctl disable lightdm
sudo systemctl set-default multi-user.target
sudo reboot
</code>

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

===== 6. Start the Desktop Temporarily =====

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

<code bash>
sudo systemctl start lightdm
</code>

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

===== 7. Stop the Desktop Temporarily =====

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

<code bash>
sudo systemctl stop lightdm
</code>