Networking

A Raspberry Pi is like a mini-computer that's both affordable and powerful, perfect for learning how to code and for creative projects, such as making a robot car move. To use a Raspberry Pi, it and your main computer need to be able to "talk" to each other, which means they have to be on the same digital network.

How to Connect Your Raspberry Pi and Computer¶

Option 1: Joining the Same Wi-Fi Network¶

The Basics: The simplest way to link your computer with the Raspberry Pi is by connecting both to the same Wi-Fi network. This can be the Wi-Fi at your home, school, or anywhere else you have access.
Troubleshooting Tips: If you're at school or work, you might not see your Raspberry Pi on the network due to extra security measures. If this happens (known as not being able to "ping" the Raspberry Pi), don't worry; just try the next solution.

Option 2: Using a Mobile Hotspot (Recommended)¶

Creating Your Network: If the first method doesn't work, you can use your smartphone or computer to create a Wi-Fi network through a feature known as a hotspot.
- For Windows Users: Look up "How to set up a mobile hotspot in Windows 10/11" for detailed instructions.
- For Linux Users:
  - Go to the system menu at the top right.
  - Click the Wi-Fi symbol, then "All Networks".
  - Click the menu in the top-right and choose "Turn On Wi-Fi Hotspot…".
  - If asked to disconnect from your current Wi-Fi, click "Turn On" to proceed.
Pro Tip: If your Raspberry Pi struggles to connect, change the hotspot to use the 2.4GHz band for better device compatibility.

Option 3: Direct Connection Using an Ethernet Cable¶

For Setup Only: You can connect your computer to the Raspberry Pi with an Ethernet cable, perfect for initial setups. However, Wi-Fi is needed for projects like controlling a robot car.
Steps:
- Connect one end of the Ethernet cable to your computer and the other to the Raspberry Pi.
- Use a command line or terminal to type ping donkeypi.local (substitute "donkeypi.local" with your Raspberry Pi's actual name).
- If possible, enable Internet Connection Sharing (ICS) on Windows or Ubuntu. This will allow you to share your WiFi connection from your Host PC to your Raspberry Pi over ethernet.

Controlling Your Raspberry Pi Remotely¶

Once connected to the same network, you can control your Raspberry Pi from your computer, using either the command line (SSH) or a graphical interface (VNC).

SSH (Secure Shell)¶

What It Is: SSH lets you send commands to your Raspberry Pi from your computer's terminal.
How to Use It:
- Make sure both devices are on the same network.
- Open a terminal and type ssh <username>@<hostname>.local (replace with your details, like ssh donkey@donkeypi.local).

VNC (Virtual Network Computing)¶

What It Is: VNC allows you to view and interact with your Raspberry Pi's desktop from your computer, making graphical tasks easier.
Setting It Up:
- Download and install RealVNC viewer from their official website, selecting the version for your operating system.
- When installing, you can skip the sign-in step.
- Open VNC Viewer, create a new connection and type your Raspberry Pi's IP address or hostname. Use the password you set on your Raspberry Pi if prompted.

Remember: The hostname is a unique name you give your Raspberry Pi during setup. It makes finding and connecting to your Raspberry Pi easier on a network.

By following these simplified steps, you're now ready to embark on exciting projects with your Raspberry Pi, from programming to building and controlling your own robot car!

Changing WiFi Settings¶

There are two main ways to adjust the network settings: through a graphical interface (like the desktop you're accustomed to) or the command line. We'll focus on the command line for its simplicity and ease of use remotely via SSH (Secure Shell), which lets you control your Pi from another computer.

Basic Networking Commands¶

Here's a straightforward guide to some basic networking commands. Remember, the command line takes what you type literally, so precision is key.

Check NetworkManager Status
- The command systemctl status NetworkManager is essentially asking, "Is the NetworkManager service active?" NetworkManager is crucial as it handles all your network connections.
  Check NetworkManager Status
```
systemctl status NetworkManager
```
Start NetworkManager
- Using sudo systemctl start NetworkManager starts NetworkManager if it's not already running. The sudo signifies you're requesting to perform an action that requires administrator rights.
  Start NetworkManager
```
sudo systemctl start NetworkManager
```
Restart NetworkManager
- Sometimes, network connections can be finicky. Issuing sudo systemctl restart NetworkManager can help by resetting your network connections, akin to toggling WiFi on your smartphone.
  Restart NetworkManager
```
sudo systemctl restart NetworkManager
```
List Available WiFi Networks
- The command nmcli dev wifi prompts your device to list all WiFi networks within range, useful for spotting available connections.
  List Available WiFi Networks
```
nmcli dev wifi
```
Connect to a WiFi Network
- With sudo nmcli dev wifi connect "SSID" password "PASSWORD", you can connect to a specific WiFi by replacing "SSID" with the network's name and "PASSWORD" with the network's password. Keep the quotation marks if your WiFi's name or password includes spaces or special characters.
  Connect to a WiFi Network
```
sudo nmcli dev wifi connect "SSID" password "PASSWORD"
```
Check Your Connection Status
- sudo systemctl restart NetworkManager lets you verify your network connection's status, ensuring everything is functioning as intended.
  Check Your Connection Status
```
sudo systemctl restart NetworkManager
```