Let's talk before our circuit

What is electricity and how can we use it?

Electricity deals with charge. 

Things can be either positively charged, meaning they want electrons, or negatively charged, meaning they want to give up electrons.

Electrons are tiny subatomic particles that give things energy.

 Everything wants to reach what we call, equilibrium. This means a balanced state. Things want to be neither negatively, nor positively charged.

In order to reach equilibrium, a negatively charged object has to give up all these extra electrons. One way to make the negatively charged object reach equilibrium is by connecting it to a positively charged object that will absorb the extra electrons.

Some things are really good at absorbing extra electrons, so good in fact,  we can give them a large amount  of them and nothing will happen. We refer to these objects as grounds.

When we connect a power source to an object that can receive electrons, a flow of electrons start. This flow of electrons is called current.

We can put electronics in between the path of the negatively charged charged object (Power Source) and the positively charged object (Ground) to turn them on.

Pieces we are going to need

15   Wires (All sizes, COLOR DOESN'T MATTER)

1  Push Button

1  10k Resistor

The bands help tell us the color!

7  220 Resistors

These are delicate, careful!

7 x LEDs (2 Green, 2 Red, 2 Yellow, 1 White)

Step 1 : Attach all the LEDs in order

(Green,Yellow,Red,White,Red,Yellow,Green)

How Do LEDs work?

LEDs are made up of a special metals. When electrons  pass through these special metals, the metal zaps the electrons full of energy.

The Electron now has to get rid of this extra energy in order to continue flowing in the circuit. It gets rid of this energy as light! (and heat)

There are 2 metals in a LED, one that wants electrons, (P-Type) and one that wants to give away electrons (N-TYPE)

With no current, they trade electrons where they touch, causing a build up of atoms in the middle that don't want to give or take electrons, it's happy (equilibrium)

GIVE ME ELECTRONS

TAKE MY ELECTRONS

I'M FULL

When we introduce current, the ground says "I can take those electrons for you" and starts stealing them from the "Full" atoms in the middle.

A flow of electrons starts!

Now the "full atoms" in the middle no longer exist, they want electrons again!

GIVE ME THOSE JUICY ELECTRONS

I GUESS I HAVE TO GIVE THEM UP. N-TYPE I'M TAKING THEM FROM YOU

More electrons?? What am I to do?

(Positive end of battery or Ground)

I need to get rid of these Electrons!!!

(Negative end of the battery or Power) 

How does this make light?

When P-Type is eating up electrons, it stores energy in those electrons, it excites them. When  P-type tries to give it back to the circuit, the electron says I'm wayyy too excited, let me give off some of this extra energy, as LIGHT! (and a bit of heat)

Electron: "TAKE ME BACK GROUND!!!"

Ground: "ONLY IF YOU LOSE SOME OF THAT EXTRA WEIGHT(ENERGY) YOU PICKED UP"

What exactly are resistors and how do they work?

They serve many purposes, but most important they limit current. ( speed of flow) 

They're made up of material that says "WHOA THERE SLOW DOWN ELECTRONS"

and the electrons oblige.

Why would we want that? 

Electronics are finely tuned and operate best with specific currents (flow). Electricity generates tons of heat! This heat can break down many objects (including LEDs). We must be careful!!!!

Step 2 : Attach our button

How does our button work?

Power pin

Connection to Digital

Connection to Ground

Yellow is Current

When our button is open, the electricity can't flow. There is a hole in our circuit. Digital receives a signal of no power or 0

When the button is  pressed, the circuit is closed.

The button is able to send a signal to Digital Pin. It says I am getting power or 1

Power pin

Connection to Digital

Connection to Ground

Yellow is Current

This isn't a normal resistor, what's it doing?

This resistor is called a pull down resistor. It's meant to cut down on Electrical Interference.

Electrical Interference is current that happens to be flowing in the air. Tons of things generate electricity (including us!).

Without the resistor, the current in the air would be enough to power the button, even when it's not clicked!

Our Digital Pin would be getting an on signal even when we aren't pressing the button. We don't want that!!

This resistor is huge (10k Ohms) and says, "Alright Electrical Interference, try to power me on now!"

5V is enough to power on the button even with the resistor (5V is what our button gets when pressed), but the electricity in the air isn't enough to power the circuit through the resistance.