1.7. How to connect to the ACU¶

There are various reasons to connect to the ACU, e.g.:

Download recorded rosbags (SFTP)
Change parameters (preferably VSCode or SSH)
Record manual rosbags, e.g. for calibration (SSH)
Camera calibration (SSH + VNC)
and so on…

This page will first explain how to connect to the ACU via Ethernet or WiFi. Then it will describe how to connect via

ssh
sftp
vnc
or VSCode

1.7.1. Connect to ACU via Ethernet or WiFi¶

To be able to connect to via an useful protocol, first their needs to be a connection via Ethernet or WiFi to the ACU.

1.7.1.1. Connect to ACU via Ehernet¶

Ubuntu

Click on the settings button under Settings / Network / Wired
Edit your IPv4 settings (manuel):
1. Adress: 192.168.201.<some random number>
2. Netmask: 255.255.0.0
3. Gateway: 192.168.201.1
4. DNS (if applicable / necessary): 192.168.201.1

Add the IP Adress of the ACU to the hostname file:

sudo sed -i.BAK "2i192.168.201.4   acu" /etc/hosts

Windows 7

Todo

This needs to be added. Please orientate at the general approach for the other host systems, research how to do it and add it.

Windows 10

Todo

This needs to be added. Please orientate at the general approach for the other host systems, research how to do it and add it.

Windows 11

Todo

This needs to be added. Please orientate at the general approach for the other host systems, research how to do it and add it.

Mac OS

Todo

This needs to be added. Please orientate at the general approach for the other host systems, research how to do it and add it.

1.7.1.1.1. Other IP Adresses in Ethernet Network¶

Table 1.1 Network devices with IP Adresses in Ethernet Network¶
Device	IP Adress	Username	Password
Switch	192.168.201.1	curemannheim	curemannheim
TCU	192.168.201.2
ACU	192.168.201.4	curemannheim	curemannheim
GPS	192.168.201.5
Lidar	192.168.201.6
ETAS	192.168.217.100

1.7.1.2. Connect to ACU via WiFi¶

Connect to the WiFi of the TCU:
1. SSID: Emma, Password: TCU!Emma2022
Add the IP of the ACU to the hostname file:

Linux and Mac OS:

Todo

Research which IP the ACU has over WiFi

Todo

Research how to add hostnames under Windows
Listing 1.3 Add the WiFi IP of the ACU to /etc/hosts¶
```
sudo sed -i.BAK "2ixxx.xxx.xxx.xxx   acu" /etc/hosts
```

1.7.2. Connect via Protocol to ACU¶

1.7.2.1. Prerequisites¶

Before you can connect via an Protocol to the ACU, you need to connect via WiFi or Ethernet. Also you should add the IP Address of the ACU and a respective hostname to the hostname file or your host OS. Both is described above.

1.7.2.2. Connect via SSH to ACU¶

See the prerequisites above.

Generate a ssh key pair if you haven’t already:
```
ssh-keygen
```
Copy your generated key file once to the ACU. Password: curemannheim
```
ssh-copy-id curemannheim@acu
```
Connect to the ACU via ssh:
```
ssh curemannheim@acu
```

1.7.2.3. Connect via SFTP to ACU¶

There are multiple ways to connect via SFTP to a SFTP server, e.g. a CLI or GUI. We will focus on different GUIs for different host systems.

1.7.2.3.1. Prerequisites:¶

See the prerequisites above.

Generate and copy a ssh key pair to the ACU, if you haven’t already done so.

1.7.2.3.2. Connect via SFTP to ACU via GUI¶

Ubuntu

Open the file browser (nautilus)
Click on Other locations in the sidebar at the bottom
Enter sftp://curemannheim@acu as server address and connect.

Windows

Todo

Improve SFTP Documentation for Windows.

Download and install winSCP. Or any other SFTP GUI for windows that you might like.

If there is anything better than winSCP don’t hesistate to edit this tutorial since the author of this documentation is focused on Ubuntu.
Setup the Connection to the ACU.

1.7.2.3.3. Connect via SFTP to ACU via CLI¶

Open the command line of you host system and connect to the ACU via sftp:
```
sftp curemannheim@acu
```

1.7.2.4. Connect via VNC to ACU¶

VNC can be used to connect a virtual desktop via ethernet / wifi.

See prerequisites above.

1.7.2.4.1. Connection¶

Connect to the ACU via SSH (see above).
Start a vncserver over the SSH Connection
```
./as_ros/utils/vnc.sh
```
Start your local VNC client
1. Ubuntu: e.g. remmina
2. Windows: e.g. RealVNC
3. Mac: [coming soon, please edit]
Connect to the ACU via VNC: acu:5901. curemannheim is the password. Or rather curemann. Passwords are cut after 8 characters.

1.7.2.4.2. Graphical User Interfaces within a docker container over VNC¶

If you want to open a graphical user interface from within a docker container, you have to do two things:

Allow the docker container to access the desktop: Execute utils/xhost.sh outside the container within a terminal over the VNC session.
Set the DISPLAY environment variable so that the correct display is used within the docker container bash session from where you want to start the graphical user interface.
```
export DISPLAY=:1
```
Todo

Check whether this is the right command.
Start the GUI.

1.7.2.5. Connect via VSCode to ACU¶

1.7.2.5.1. Prerequisites¶

Todo

Link correct section for VSCode setup.

You atleast have to install VSCode with the Remote - SSH Extension. It is recommended and assumed that you setup the VSCode as desribed in Visual Studio Code as standardized IDE.
Generated ssh key pair and copied you ssh key pair to the ACU, see SSH Connection above.

1.7.2.5.2. Connection¶

Click on the Remote Extension (Display with >< in a small circle) in the sidebar and choose Remote in the REMOTE EXPLORER dropdown at the top.
Hover over SSH and add a new connection: ssh curemannheim@acu. Choose the correct ssh key pair.
Connect to the ssh connection within VSCode in the current or in a new window. This may take in some minutes when you connect for the first time (in a while).
Open the workspace:
1. Either open /home/curemannheim/as_ros
2. Or install the Dev Containers extension and connect to the docker container as explained in Connect to an AS ROS container with VSCode.