You have the controller, you have the diode. The controller has a number of pins (holes). Where should you put the diode so that it starts blinking?

The small holes on the controller are called pins. On our controller we have 32 pins. The more pins that you have, the more elements you can controller with this microcontroller. For this video the interesting pins and 13 and GND

• #309
• 15 Nov 2016
• 3:07

### How does the diode blink

In a very simplified view - there is current flowing in the system and this current flows from pin 13 to the GND. The current is "small charged particles called electrons". We need the current to flow through the diode. The particles must move through the diode.

This light emitting diode has two special features:

1. It allows the current to flow in only one direction
2. It emits light when the current is flowing

The diode has two legs. The constructors of the diod have decided to make on of the legs longer. In this way they are telling us how should the current flow in the system. How should the small particles move. The they should move from the longer to the shorter leg.

The longer leg should be added on PIN 13 and the shorter leg on PIN GND

### English

This here is the Arduino controller. It has a number of pins. This here is the diode. It has two legs. Question is: Where should we put this diode so that it starts blinking?

The small holes on the controller are called pins. We have an overall of 32 pins. Generally speaking, the more pins your controller has, the more elements you can control with it. There are two pins that are interesting for us for this video. The first pin is the Ground pin. Right here. It is located right here and it has G and D marked on it. The next pin is the pin with number 13. You can see it here. And for the video you should use exactly this pin. The pin with number 13. The current that will make the diode emit light because this is a light emitting diode and current flows through this diode and it emits light the current will flow from pin 13 to the ground. Now, to make the diode emit light we need to have current flowing through it. This diode is a special element with two main features. It emits light when current is flowing through it and it allows the current to flow in only one direction. To know the direction in which the current should flow the constructors of this diode have decided to make one of the legs shorter than the other. You can see it here. The current will flow from the longer leg to the shorter leg. And that's why we should add the longer leg to pin 13. And the shorter leg to pin Ground. Because the current will flow from pin 13 to the ground. Now, I know that this is a very very simplified view on how an electrical circuit works. Remember that the shorter leg of the diode should be attached to the ground. Like this.

You might wonder why is the diode not blinking now. This is because we have not written the program and we'll write the program in the next step.

## Courses and lessons with this Tutorial

This Tutorial is used in the following courses and lessons

• 16
• 25:27
• 6
• 11
• 0
• 6
• 3d_rotation 2