What is the Raspberry Pi

What is the Raspberry Pi Titelbild



What is a Raspberry Pi?

Hello! Glad to see that you have made it past the introduction! Being human, we’re sure you sometimes question who you are, why you are, and what the reason for existing is. Well, we don’t know the answer either. What we do know however, is that the Raspberry Pi is an awesome computer for learning to code, and not because the name reminds us of pie with raspberry flavor, at least that’s not the only reason.

This small device has a lot of interesting and practical capabilities that make life easier for programming apprentices. Apart from its slim appearance and all of the important connections it includes for electricity, display, mouse, and a tiny usb vacuum cleaner you might need for your keyboard, the Pi also has what is called a GPIO interface. This of course makes the heart of a tinkerer beat faster. When done properly, you can connect just about anything. From LEDs, to sensors, to a rocket control unit for your first Mars mission. All you need is an imagination and the correct program code. Fortunately, you’ll find all these things you need to get started in your Coding World Starter Kit.

The basic idea of the Raspberry Pi is to enable young people to learn programming. This Mini PC costs around 70€, uses open source operating systems, and runs with the Python programming language. The Pi is so successful that more than 13 million of the small computers were produced. The Python programming language is at least as great as pie with raspberry flavor because even though Python is simple and easy to learn, you can do lots of exciting things with it.

Starting and setting up the Raspberry Pi

Before you can start the engines of your Pi, you have to set it up. Following this 4-Point-Plan is the best solution for all involved persons and computers:

Put an SD-Card with Noobs already installed in the Micro-SD card Slot on your Pi. If you don’t know where to get such a Micro-SD card, visit our online platform. Connect the Pi to a display with an HDMI cable. Connect a keyboard and mouse to the Pi. Bring your Pi to life by plugging in a power plug.

When you’ve done everything correctly, all pieces are in place, and Noobs is correctly installed on the SD card, the LEDs on the Pi should blink wildly and you will see the Noobs Start Menu on the display.

Noobs isn’t the operating system we will be working with, but rather, it is the system used to install the operating system of our choice. You probably aren’t sure which system you should use, so here is a hint: You want to install Raspbian. Choose Raspbian from the list (with Enter). Choose the language you want to work with. You’re able to change language and keyboard layout with the keys 1 and 9. After you have done this, you press “i” to start the installation process of the chosen operating system. And yes, you are sure about it! The installation will take quite a few minutes (in our test we waited for exact 19 minutes and 59 seconds).

Now, Raspbian starts for the first time. You see the boot up text on your display? This shows you that Raspbian is starting. The meaning of the text isn’t relevant right now. The only important thing is how cool it looks. You and your Pi are starting for the first time, so just relax and be patient. It may take a few minutes.

At the first start you will see the desktop of Raspbian. As we said: the Raspberry Pi is a real computer, just a little bit smaller. Even though the mouse is a great thing, we will primarily work with the terminal. You can get to it by going to: Menu (the raspberry on top-left cornerO -> Accessories -> Terminal. If you just connected a keyboard, you can get to this menu point with the Windows key /between Ctrl and Alt).

sudo raspi-config

By the way, this is what a Terminal command looks like. The word “Bash” and also the “$” at the beginning of the command sign tell you that we have a terminal command here. When writing the command, make sure you leave out the “$”. So, enter the following command without “$”, so that we can adjust some things:





Configuring sudo raspi-config

At this point you can easily navigate with the arrow keys and the tab key. If you want to confirm your input, you should choose the enter key.

Please enable “SSH” under “Interfacing Options” in the menu. You will need it to use your Pi without a display. Last step, we can’t wait any longer: you also have to enable “P4 SsPI” under “Interfacing Options”. It is important for your work with the display. To enable “SPI” you have to answer the following questions with “Yes”. By doing this we are ensuring SPI also starts when we start the Pi.

Well, that was kind of strenuous, wasn’t it? Now you can reboot the Pi with all new settings whilst choosing “Finish”.

sudo reboot

If you missed something in the settings, you can use the command

sudo raspi-config

to get back to the settings menu. The default login credentials are ”pi” for the username and ”raspberry” for the password. First you have to enter the username at “raspberry pi login:” and second the password ”raspberry” at “Password”. Don’t be surprised when you don’t see any asterisks when typing the password. It’s just a safety measure. When the Pi is starting with the Desktop, you usually don’t have to log in.

How do I orient myself on the Raspberry Pi?

As all cool gangsters from films, we will also use the terminal. That’s the thing showing everything in text form and just understanding text form, too. Basically, it’s the operating system you know from normal computers, just without the graphical user interface. We use this form so that we can concentrate on our program and on our evil world conquest plans.

And also because we don’t want to think about the correct web browser.

You will find all important commands for the terminal on our Cheat-Sheet that accompanies the booklet. For the beginning of your journey, we will explain the most important commands to you and you can try them out. When you start your Pi with the Desktop you have to start the terminal first. Just choose Menu -> Accessories -> Terminal. You are starting in the home directory of your Pi. You can imagine this as a big folder. In this folder you can create new files, which contain your program code or the canteen menu for the next week. Just as your parents don’t want your room to be unorganized, you don’t want chaos in your folder. To help this, you can create sub folders as below:

mkdir testFolder

And you can change into these directories with

cd testFolder

You are entering in the folder we just created before. You can see that it is a terminal command by the $. So please don’t enter these. You can also see that you changed into another folder because the path is shown before the $ in the terminal.

And with the following command you can change again to the folder above: einfaches:

cd ..

Just changing the folder is a cool thing but there is also a terminal command to find out what is in inside the folder. We can even place everything from another folder to different files inside a folder.

ls

Now the Raspberry Pi shows you the complete content of the folder. You should also see the folder you just created in a blue typing. Is life not just so easy with the Pi?

If you want to know more about the full path of the folder you are currently in, you can just use the following command to print the full path:

pwd

Not the folder you want to be in? No problem. Just use cd and the name of the folder to change your current position.

cd otherFolder

Just be sure to use your desired folder name instead of otherFolder ;)

Wifi Connection

In the old days you established a physical connection via ethernet or a wifi stick to connect your Pi to the internet. Nowadays, however, this and bluetooth are already built into the Pi starting with Version 3. Thanks to this we can now just get started with the internet and the Pi. An internet connection is important if you need to download additional resources or even just browse the web. All you need now for the next step is a working wifi connection not to far aways from you and the data for this wifi connection. You also can configure your internet access via the desktop environment. This can be done through the wifi symbol on the top navigation bar, but we will explain how to use the terminal for this. In our method, we only need to edit a single file and restart the Pi afterwards.

sudo nano /etc/wpa_supplicant/wpa_supplicant.conf 
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
        ssid="Your_WIFI_Name"
        psk="Your_WIFI_Password"
        key_mgmt=WPA-PSK
} 

After opening the file, you should see that everything is filled up until network. In the next line we need to save the name of our wifi network. This name is also called ssid. You need to write the name between the two “”. In psk we need to save the password. The third argument we need to make with key_mgmt= is the type of network we are connecting to. If you use standard setting, WPA-PSK should be fine. If your wifi network has no password, you just can remove the line with psk in the beginning and write key_mgmt=None.

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