What is an Arduino microcontroller

Understanding Arduino Power.

The Arduino can be powered in two ways. You can either use the battery jack to attach a battery that has a voltage of between 6 to 12 volts, or you can power the Arduino from your computer, which will provide a lower voltage of max 5 volts from the computer's USB port.

The advantages of using a battery to power the Arduino is that your project will be more mobile and you will be able to move around with it (without having to keep your computer attached).

You would connect the battery to the battery jack shown below.

Connecting the Arduino to your computer

The Arduino will be connected to a computer with a micro USB cable. You will need to do that once you have written the code on the computer, and want to upload it to your Arduino.

You might also keep the computer connected to the Arduino with the same cable if you are powering the Arduino from the computer. The computer will provide a maximum of 5v through the USB port.

Output voltage of pins

No matter which kind or voltage or power you use to power the Arduino, the output voltage at the pins will always be 5v.

So even if you supply it with 12v from a battery, there will be a voltage regulator inside the Arduino that decreases the voltage to 5v at the pins. This is really important so that you don't blow any components that you connect to the Arduino. (Supplying a component with a voltage higher than its specification can cause damage to the component).

Now lets look at the different kinds of pins on the Arduino.

The Power pins

We have pins that are linked directly to the power supply. They are all in a row, and are used when you need to connect to Ground (GND) or the battery directly (VN) or a 5V pin which is always on. You will learn more about these pins and when they are used, but for now, just take note of where they are on the Arduino board.

Male and Female pins

You might also have noticed that some of the pins on this Arduino are like tiny boxes (female pins) and others have a sharp rod sticking out (male pins).

Because components sometimes have male wires and others have female wires, it is quite handy to have male and female pins on the Arduino.

For both the Digital and Analog pins we have a choice...male or female. So depending on what our component wire looks like, we can connect easily to the board.

To be clear, if you are looking to connect to digital pin 9, you will find a female digital pin 9 and a male digital pin 9. You can connect to either and it won't make any difference which one you choose to connect to, the current will run through both.

Digital and Analog pins

You will learn alot more about Digital and analog pins in this course. For now it is only important to know that you have one row of Digital pins. In total 14 pins, counting from 0 to 13 at the top of the board.

And you have 6 Analog pins at the bottom of the board, counting from 0 to 5.

These pins will be used to connect and signal to and from the components that we attach to the Arduino.

Lastly we have the on board LEDs.

Pin 13 LED

The digital pin 13 is connected to an on board LED, which is extremely useful for testing code without having to wire up an external LED. You just tell tell the LED at pin 13 to light up. We will use this LED in one of our first projects.

RX and TX LEDs

There are LEDs that light up whenever the Arduino is receiving or transmitting information. This is also very useful for knowing what going on inside the 'brain' of the Arduino.