Tutorial beginner 2:
Switch on a LED!
Content of the tutorial:
Dear User, have you read the first tutorial?
It is important you have read it before to go on, otherwise you could not understand everything we are going to describe here.
So, let's start with the first very simple application example: how to switch on a Led.
You can find the Project I'm going to describe in the drop-down list of examples in the Devise Home header area:
Actually it is a very simple and maybe not so useful example in real world,
because there is no need to use an intelligent controller to merely switch on a Led.
Even if this Project is ready to be loaded from the examples drop-down list, now I'm going to show you how to build it completely from scratch.
So, starting from an empty project, we need to add and configure the four objects that will
compose the final Project. But before that we have also to fill the project properties.
1. Fill the Project Properties.
In this step very few things to do are required:
- Give the title of the Project, i.e. a slogan that remind you the purpose of the Project.
- Set your name and the name of your company if exists.
- Write a brief (max 80 characters) description of the Project.
2. Add the controller (Arduino Uno).
When the project is empty, or when we click in a white area of the whiteboard,
the available controllers that we can use for the project are shown in the
upper right side of the screen.
Now the controller that you have added is selected (rounded by a red rectangle) and the list of available devices that can be attached to is magically shown. Furthermore the list of properties is shown in the bottom right side of your screen.
3. Add the push button.
Let's click on the button:
Perfect! Now the button is connected to the controller: how is it connected?
Uhm, something is missing... Yes, you are right... we still need to define what
pin of the controller the button is connected to...
Of course the pin number must be the one we will really connect when we will physically cable those components. Let's set the pin number 2.
4. Add the Led.
It's time to add the Led. The procedure is the identical as the button one. You can connect a a led or a relay or whethever you like. As before, don't forget to specify the pin number of the controller the led is connected to. Let's set the pin number 13.
5. Link the button to the led.
What does it mean? Link the button to the led means that we want that the action of the button is trasferred to the led. When we push the button, the led lights on!
As before, we are now going to perform one more very simple action.
Now its time to save and download the project, but I'm sure that you know how to do it, as the procedure has been described on the previous tutorial
Once we have saved the downloaded zip file on our disk, how can we proceed to use it?
First of all we have to cable the button and the led to the controller, than we need
to load the downloaded file on Arduino. After that we can proceed with our test.
The 'bill of material' is listed below:
- 1 Arduino Uno, the controller.
- 1 Push Button.
- 1 USB cable, to connect Arduino to the PC.
- 1 Small breadboard.
- Some pieces of unipolar cable.
And the Led? No, you don't need it. Actually led itself is already present on the Arduino board and is already connected to the pin 13.
The following picture shows all the connections needed by the devices:
Of course do not forget to connect the Arduino board to your PC through a usb cable or to a power supply.
I do not think I have to provide more info about the connection among those components, it seems to be very easy to do at this level. However, for any projects you design, you can click on the hardware connections button . It provides you a complete and detailed connection schema you can print out and use to build your system.
Even if the complete documentation can be easily found on Arduino website, I will summarize the main operations needed to correctly load the files. The following instructions are applicable to all the future projects related to Arduino as well.
First you need to install the Arduino IDE! ... What? ... What is this?
Yes, unfortunately it is a mandatory step, but the good news is that you have to do it only once, only the first time!
The Arduino IDE is the application that allows you to write the programming code and to load it on Arduino. Don't worry, you don't have to write any code as you have just downloaded it, you need Arduino IDE to load the code on Arduino only!
Well, let's proceed with the installation. Here you can download the Arduino IDE
Once downloaded and installed, you can run the IDE and configure it: you have to do only two steps for now:
- select the type of Arduino: 'Arduino Uno' for this Project
- select the the USB port Arduino is attached to: something like COM10, but it could be a different number. My suggestion is to try different choices until it works.
Well, now it's time to get back to our project. We have just downloaded a zip file that is a container of other files:
- *.h file(s)
- *.ino file(s)
We should now create somewhere in the hard disk a folder that has exactly the same name of
the two files without their extention: in our example the downloaded .zip file includes two files
called sketch_dome_Uno_0.ino and sketch_dome_Uno_0.h, so create a folder called it is sketch_dome_Uno_0.
Ok, now double click on the '*.ino' file and the IDE will be opened showing the content of this file inside its screen. You can see now the Arduino source code that implements the functionalities of your project, in our case switch on a led. Without Devise Home you should have handly written this code by yourself.
If you are able to do it, you can also modify this code to change the behavior of your project... But don't worry, basically it is not required at all. The code is fully working by itself.
What you have to do now is load the program on the controller. It is as usually very simple: click on the Load buttone shown in the picture below and wait a few time, less than one minutes. If the previous steps have been correctly executed, all your work is now ready to be tested!
As said before, the purpose of this simple example is to become familiar with Devise Home and with Arduino. It is not a real useful application. If you want to learn more and go inside more and more useful applications, you can go ahead and read the next tutorial!