Channeling imagination

The Arduino Designer: an Eclipse programming platform for kids

MlanieBats
neko.1

A small computer for little fingers with big aspirations.

Children are curious by nature:
they explore, question, wonder, and by doing so, learn. From the
moment of their birth, likely even before, humans are meant to
learn new things. When we are curious about something new, we want
to explore it.

A good way to discover is to explore by yourself, trying,
working through successes and failures. In this way, kids learn
causes and effects.

Today, the world is made of computers. At home, in TVs, DVD
players, coffee machines, electronic toys, pet robots, cars,
planes, phones…the list is endless. Nowadays kids are used to
playing with tablets and computers. They are curious to understand
how a video game is created, how computers work and all about
anything electronic.

In our connected world, one of the things kids have to learn is
electronics. The idea of learning electronics for them is mostly to
understand that they can use sensors to listen to the environment
and actuators with which they can interact. We expect that they
understand that these modules are connected to a platform which
contains software.

Open Hardware

The problem with electronic devices is that most of the time
they are composed of very tiny components, which are not easy to be
manipulated by kids. It is also very easy to make a bad connection
and damage your electronic module or component.

LittleBits is an open source library of electronic modules that
snap together with tiny magnets. There is no soldering, no wiring,
and no programming required. The devices is really great for
helping to foster an understanding of electronics without any
programming knowledge, and to make kids perceive and grasp the
connection between software and hardware modules.

Nowadays, it is really easy to get good material to learn
electronics thanks to the open hardware initiative. The most famous
open hardware platform is Arduino. With Arduino you get a piece of
hardware, but also documentation and a development environment that
fits together with the hardware.

The Arduino board is like a small computer that can be
programmed as often as needed. As a computer, it provides I/O
interaction, through digital and analog pins. Arduino can sense the
environment by receiving input from a variety of sensors and can
affect its surroundings by controlling lights, motors, and other
actuators.

The microcontroller on the board is an Atmel AVR microcontroller
and is usually programmed using the Arduino programming language
and the Arduino development environment. In fact, the Arduino
language is just C++ using a specific Arduino library and syntaxic
sugar that makes it much easier than normal C++.

What’s great about Arduino is that it is cheap and really easy
to find. There are many efficient providers available online, for
example AdaFruit, DFRobot, SeeedStudio, and SnootLab. They provide
an incredible amount of modules! Order and two days later you will
receive your new toy at home.

Learn
programming

Programming is all around us! For this reason, to fully
understand our world, our kids also have to learn coding. Many
different initiatives are arising to teach programming to kids:
Programatoo, Devoxx4Kids, Greenlight, Coding Goûter, either based
on open source software or proprietary software. The most famous,
TurtleLogo is for the older ones. More recently, Scratch has become
more popular. These tools use different approaches to teach
programming.

In TurtleLogo kids write text to move a small turtle cursor in
order to draw shapes. No graphical UI, very simple language. They
learn the concepts of programming and understand that a program is
just a sequence of instructions.

In Scratch you drag and drop elements from a palette to animate
a character. This tool is a complete IDE which allows kids to
create cartoons, video games, movies and provides a more graphical
UI. Kids have to assemble puzzle pieces which are instructions to
describe a program.

These tools are great to learn what programming is. There are
other kinds of tools that allow kids to program the real world by
interacting with sensors and actuators. Open source tools like
Scratch4Arduino or Ardublock provide UIs for simple programming of
the Arduino platform. Thanks to these tools, kids can develop a
small program, upload and run it on hardware platforms and so
interact with the real world.

Simplified Eclipse for kids

Eclipse is one of the most famous IDEs, with millions of users
all over the world. So we could imagine that kids could use it also
to learn programming. But if we give them the original Eclipse IDE,
the UI and the default available languages (such as Java or C) are
too complex for kids to discover programming.

Arduino Designer is born from our desire to give
kids a tool to code the real world and from our aspiration to make
Eclipse accessible to them.
The idea was to develop a
new software to allow kids to create small programs for
Arduino.

Our first action was to simplify the Eclipse UI, the project
lifecycle and to provide a graphical block language to be able to
develop simple programs and run them on electronic modules. The
purpose is to provide a simple dedicated tool which gives the
possibility to discover the effects a software program can have on
electronic modules.

The UI of the Arduino Designer defines no menu, just one toolbar
with 4 different buttons to : manage the project, define the
hardware modules used and to define the software that would be
uploaded on the hardware platform.

A dashboard helps children by indicating what is the next
step in the development process. There are three steps to
follow:

  1. Describe the hardware platform and the
    connected hardware modules: the child must define the hardware
    platform they are using and the different sensors and actuators he
    connects to the Arduino. This is done by defining
    platforms, modules and wires thanks to
    the tools available in the palette of the Hardware
    representation.

  2. Describe the software: Kids write the sketch
    (in Arduino speak, a program) that describes the behavior that the
    hardware platform should have. This description is done using
    a simple graphical block-based
    language. With this graphical language, it is possible to create
    instructions like
    while, repeat or if instructions, which introduces kids to the basic
    control structures of most programming languages. It is also
    possible to use functions like
    delay, to reference hardware modules, to create variables and constants and use some mathematical
    operators
    . The language
    included in the first prototype remains close to the text-based
    Arduino language, providing a direct connection between the
    graphical representation and the textual representation of a
    program.

  1. Upload the software to the target: And finally,
    to run the software on the hardware platform, the user simply has
    to upload the sketch to the target thanks to the upload button
    available in the toolbar or from the dashboard.

Sirius

The Arduino Designer is based on Sirius, a new
project in Eclipse to quickly define multi-view workbenches based
on DSL with dedicated representations.

During the prototype development phase, Sirius allows to quickly
develop a specific modeler dedicated to Arduino. The development is
easy, dynamic and iterative thanks to a live preview. For the kids,
they get a tooling completely adapted to the development of small
Arduino projects and simple to use.

  1. Define the language: To use Sirius to create the designer, we
    started by representing the Arduino language as an ecore
    metamodel.

  2. Specify representations: Second step, we specified the different
    representations: Dashboard, Hardware, Sketch. Then we
    mapped the different concepts defined in the metamodel to graphical
    elements and defined the tools provided by the designer palettes
    for each representation.

  1. Write generator: Next step was to develop a small generator with
    Acceleo to generate the Arduino sketch from the
    model.

    The generator creates .ino files for sketches identical to the
    one usually manually written with the Arduino IDE. As the Arduino
    language is based on C/C++, it links against AVR Libc and allows
    the use of any of its functions. The AVR Libc package provides a
    subset of the standard C library for Atmel AVR microcontrollers
    like Arduino.

  1. If we look at the generated code, we can see that Arduino
    programs are divided in two main parts. The setup()
    function is called when a sketch starts. It is used to initialize
    variables, pin modes, start some libraries, etc. The setup function
    will only run once, after each powerup or reset of the Arduino
    board. After generating the setup() function, the
    generator creates a loop() function. This function is
    called in an infinite loop, and is therefore used to implement the
    behavior of the system, typically read data from sensors, decide
    what to do, and perform actions using actuators.

  2. Cross compile code for the target: When you use the Arduino
    environment the compilation and upload actions are directly
    integrated. Here we integrate the generation and the compilation of
    .ino files in the Arduino Designer which is an Eclipse application.
    The generated files are compiled using avr-gcc which is a
    cross-compiler for the AVR chip that runs the Arduino. After
    building, a new directory has been created which contains all the
    object files.

  3. Upload the sketch on the Arduino platform: Then the upload
    action from the toolbar simply upload the software on the target by
    using avrdude. avrdude is a very handy utility for loading
    code into AVR microcontrollers. As Arduino ships with its own
    bootloader, it is possible to load and run code using only a single
    USB cable connecting the computer to the board. Usually this cable
    comes with the Arduino kit. The kids using the Arduino Designer do
    not see any of these steps as they are all integrated in the upload
    action.

Code and Examples on github

The code is available under EPL license on github: http://github/mbats/arduino

In this first prototype, we provide the hardware components
included in the DFRobot Ardublock kit which contains: ambient light
sensor, infrared sensor, sound sensor, push buttons, rotation
sensor, servo motors and we also support a fan. We also provide
some example sketches.

As usual with a new language, the first example developed was
the “Hello world” sketch and as we are programming hardware
components, it consists in blinking an LED.

int brightness;

void setup() {

brightness=0;

}

void loop() {

while ((brightness<255))

{

brightness=(brightness+1);

analogWrite(11,255-(brightness));

delay(8);

}

while ((brightness>1))

{

brightness=(brightness-1);

analogWrite(11,255-(brightness));

delay(8);

}

delay(200);

} 

As explained before, on Arduino the main program is just an
infinite loop. So the sketch will be valid only when the loop will
be closed. What we have to do to make an LED blink? What does it
mean? It just means switch the LED “on”, then keep it powered
during a certain time, after switch it to “off” and keep it like
this during a certain delay and loop.

The second available example demonstrates how to use sensors.
From the hardware point of view, we need to connect an LED and a
pressed button. The following sketch references an LED and connects
it to a push button in order to switch on/off the LED according to
whether the button is pressed or not.

Other examples demonstrate how to use the loop instructions, the
variables and mathematical operators, for instance to change the
brightness of an LED in order to get a fading light.

As you can see the Arduino Designer allows to develop
really simple projects. But thanks to these different simple
functions we are able to build more complex projects. One thing
that kids and adults enjoyed quite a bit is creating robots. So we
also provide a tutorial to create an electronic cat based on high
tech composite materials coming from trash cans, made out of
cardboard and lots of scotch tape.

 

  

The cat can:

  • Feel when you push
    its nose button, at which point it will switch on its flashing
    necklace.

  • Detect something
    close to its eyes, which will operate its servo-motored tail.

  • Hear sound, which
    will start its bubble machine. The bubble machine is composed of a
    servo that controls the bubble stick and a fan.

Join us and contribute

It is really easy thanks to Sirius to create specific designers,
you can have a look at the Sirius website to get more detailed
information about the principles of Sirius :http://www.eclipse.org/sirius.

Go to github to get the Arduino
Designer code and examples, clone it and contribute! We will be
happy to integrate your code for the modeler, other application
examples, tutorials, documentation – anything you need.

Mélanie
Bats

Mélanie Bats works as a software developer at
Obeo. In her daily work, she is mainly focused on the development
of modeling tools with Sirius (UML Designer/SysML Designer). In her
free time she is interested in Arduino stuff and contributes some
Eclipse plugins for cross compilation. She is also a free software
activist who has organized and participated in free software events
in the Toulouse area.

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