Difference between revisions of "RPi Education/Manual"

From eLinux.org
Jump to: navigation, search
(Hello world: more syntaxhighlight)
Line 172: Line 172:
  <tt>Hello World!</tt>
  <tt>Hello World!</tt>
Most all code is executed in order; from top to bottom, left to right, and in English.
===Control flow statements===
*Decision-making statements (if-then, if-then-else, switch)
*Looping statements (for, while, do-while, break, continue)
*branching statements (fork join)
* '''maybe we can just link to the SDKs that are shipped with the book?'''
reusable blocks of code
are basically function containers, and yet so much more.

Revision as of 11:53, 25 April 2012

Please add any contributions to the educational user manual here. These should take the form of step-by-step guides or listings with descriptions. Alternatively, email your contribution by taking a look at this Raspberry Pi forum posting.



The objective is to educate people in computer science.


Cheap hardware with 1/2 open specifications allow the masses to learn modern computer science.

  1. Plug in your RPi to your monitor with the hdmi and usb cable
  2. Plug in your mouse and keyboard to your monitor
  3. Plug in your monitor power and turn it on.


Linux is used, it is open source, user friendly, and technically capable.

Language Selection

Beginners should select a high level language. Advanced users may select different languages combinations depending on the available libraries, programming paradigm, and optimizations.

All code is executed in binary assembled from assembly code compiled from a language sometimes in-turn compiled from other higher level languages.

There are 2 main interfaces for most all applications in linux CLI, and GUI, while GUIs are user friendly CLIs are more simple to build and can be used as building blocks for more complicated tools/toys.

It is considered good programming to use an iterative approach, using existing tools and patterns as much as possible, as such it is customary to start with a hello world:

Hello world


Bash is the language of the terminal.

  1. open the termonal application
  2. type:
echo Hello World!

That was a computer program,

If you want to learn more about the echo command you can type

man echo

(press q to quit)

Now let's make our program into runnable file:

  1. nano hi.sh
  2. echo Hello $1!
  3. [Ctrl]+[x],[y],[enter]
  4. bash hi.sh Tux

Which should ouput: Hello Tux!


Make a file called hi.py, put

print("Hello, world!")

in it and run it with python hi.py

Now a GUI version:


import pygtk
import gtk
class Whc:
        def __init__(self):
                self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
                self.window.connect("destroy", self.destroy)
                self.label = gtk.Label("Hello, World!")
        def destroy(self, widget, data=None):
def main(self):
        if __name__ == "__main__":
                base = Whc()


Create a text file called 'Hello.java' with the following content:

public class Hello {
    public static void main(String[] args) {
        System.out.println("Hello World!");

Now compile your file as follows:

javac Hello.java

To run your program:

java Hello

It should respond with Hello World!


Create a Text File called 'hello.c' which contains the following:

#include "stdio.h"
void main() {
        printf("Hello World!\n");

Now compile the file using 'cc' , like this:

cc hello.c

If all went well, there will no error messages and a new file called 'a.out' should have been created by the compiler. To run your program type:


It should report back with your message:

Hello World!


For starters the famous "Hello world!" example. Save the following code in a file called helloworld.cpp in a directory of your choice (e.g. ~/cpp). The filename can be chosen arbitrarily, but should describe the content.

 //Compile with: g++ helloworld.cpp -o helloworld
 #include <iostream>
 using namespace std;
 int main () {
     cout << "Hello world!" << endl;
     return 0;

Open a terminal and switch to the directory, which contains the saved file.

cd ~/cpp

Make sure with ls that you are in the correct directory. It should output helloworld.cpp and all other files in this directory (if any).

Now it is time to translate your code so your computer can understand it. This is called compiling.

g++ helloworld.cpp -o helloworld

If everything went ok, nothing is printed. Now run your program.


This outputs Hello world! on the command line.


A "Hello World" example in Perl.

Create a file called 'hello.pl' in a directory of your choice, with the following contents:


print "Hello World!\n";

To run your program type:

perl hello.pl

It should respond with:

Hello World!


Most all code is executed in order; from top to bottom, left to right, and in English.

Control flow statements

  • Decision-making statements (if-then, if-then-else, switch)
  • Looping statements (for, while, do-while, break, continue)
  • branching statements (fork join)


  • maybe we can just link to the SDKs that are shipped with the book?


reusable blocks of code


are basically function containers, and yet so much more.


Features, libraries, and limitations.








Useful tools and fun toys.

Theory and tools

  • Version Control: git, svn, etc
  • Iterative and Test Driven Development
  • Writing software for someone else (User Stories, Use Cases, requirements, contracts)
  • editors and IDEs: vim, gedit, eclipse, etc








Algorithms, Heuristics, Design Patterns, and Optimization.