Basics of the Raspberry Pi – How it all Works

Basics of the Raspberry Pi – Part 2
Part 1 – Basic Setup
Part 3 – Turning a light on and off 

How it all works – Part 2

Lets figure out how all of this comes together!  I promise once you do this once then everything will click and you will be off to bigger and better projects with the Raspberry Pi.  For now lets talk about a simple project; below is our 1,000 foot view of what we want to accomplish.  (All of these components where referenced in Part 1 of this blog)

This all seems fairly simple until you get to the breadboard and how/where too plug in your wires and components.   I can tell you that this is a fairly dummy proof process; I have plugged components into the wrong places and have yet to break anything.  I know I did something wrong when the Raspberry Pi immediately resets/reboots.  Just please be sure to understand your voltages and when to use resistors otherwise the components that you use could easily break/pop/die.

Ok, so to recap we have now performed the following steps and are ready to start interacting with the breadboard.

  1. Plugged our 40 Pin Cable into our Raspberry Pi
  2. Plugged the other end of the 40 Pin Cable into our GPIO Extension Board
  3. Seeded our GPIO Extension Board into our BreadBoard

Before we start plugging wires into the breadboard we need to understand how the GPIO Extension Board.  The Breadboard itself is really a super simplistic device; I have outlined how it works below.

This is a device designed to assist in the creation of completing circuits.  Basically every red line that is overlaying the breadboard represents a metal connection that ensures that all pin holes are inter-connected.

When you plug the GPIO Board into this, you really want to plug it in so that one half of the pins are on the right side and the second half are on the left side as shown in the picture below.

You can now start creating full circuits that connect different Pins on the GPIO Extension Board;  which is essentially the same thing as creating circuits directly on the 40 Pins on the Raspberry Pi device.  This is just the safe and easy way to do it.

The only thing left to do is build a complete circuit on the BreadBoard!  To Create a Complete Circuit we will perform the following steps:

  1. Plug one end of your resistor into the breadboard line that the GPIO 25 connector from the GPIO Extension Board aligns to; plug the other end of the resistor into a line on the breadboard that is free.
  2. On the same line the resistor connects to, plug in one end of your LED light
  3. Plug in the second end of the LED light into a line that aligns to a Ground pin “GRND” on the GPIO Extension Board.

When you are done then your breadboard should be similar to the image below.  There are infinite ways to create this circuit, just be sure to get that resistor into the circuit so you do not damage up your LED light.

Below is the same implementation as above.

We are ready to turn on our Raspberry Pi and start creating some code to control our circuit.  We will be using Java in this demo to control our LED light.  I am choosing Java not because it is the more suitable language for interacting with the Raspberry Pi but because it is the most popular language being used with this device.

Part 3 – Turning a light on and off (using Java)

Side note about using Java with the Raspberry Pi: I can tell you that I have already ran into instances that exposes the Java flaws with the Raspberry Pi but don’t fret too much; all shortcomings have easy work arounds.  I plan on creating a blog focused solely on this topic.

Basics of the Raspberry Pi – Part 2
Part 1 – Basic Setup
Part 3 – Turning a light on and off 

Basics of the Raspberry Pi – Setup

Basics of the Raspberry Pi – Part 1
Part 2 – How it all works 
Part 3 – Turning a light on and off 

Part 1: Raspberry Pi – Prototyping, Simple Lights and some Java

I kept hearing about the Raspberry Pi and all of the wonderful things you can do with it. It was time for me to roll up my sleeves and dig in with my first real project.  I can honestly say that I seriously struggled to find all of the information and documentation out there that I needed put together in a way that I could easily take it and run with it.  Well after many hours of tinkering I decided to write my own guide in words that makes sense to how my mind works.

In this blog I will go over everything you need to know about the Raspberry Pi from what to buy down to running some basic java code to turn on an led.

Here is what you need and more importantly; why you need it!  The total cost of all of this should not exceed $65 unless you cannot find #9 at a good price.

  1. Raspberry Pi – This is basically your computer
  2. Micro SD Card  – This is your hard drive that you will install your Operating System on
  3. 40 Pin Cable – This is used to connect to the Breakout Board (#4)
  4. GPIO Extension Board (Breakout Board) – This is placed on the BreadBoard and basically allows you to create controllable circuits with the Raspberry Pi
  5. BreadBoard – This is nothing more than a bunch of metal wires and pin holes for you to create circuits on using Jumper Cables that connect pins from the Breakout Board (I will explain in detail later)
  6. Resistor – This is here to reduce the voltage that will run through your LED; if not it may melt or pop!
  7. LED – This is your LED that basically will tell us if the circuit that we created is active or not.
  8. Ambition

Lets get started!  The first thing that we need to do is setup our Raspberry Pi.  This is probably the easiest part of the entire thing.  If your Raspberry Pi came with an SD card then it probably already has the OS installer setup.  You will need to download and install NOOBS onto your SD Card. NOOBS is an easy operating system installer which contains Raspbian which will be the Operating System that you interface with when running your code.

Once you download this file; simply unzip it onto your SD Card.  Now lets pop the SD Card in your Raspberry Pi and fire it up.  Your goal is to see a screen like this one. 

The next part is quiet easy; all you have to do is click the CheckBox for Raspbian and click install.  This process takes about 10-15 minutes or so.  
Once the install is finished the system will reboot and load up your brand new Raspbian GUI.

This base install is all loaded up with some of the tools you will need to start programming.  Most notably it already has Java SDK, VNC Server, SSH Server, and other countless developer tools.  Some of which you will need to enable through the rasp-config tool.  The easiest way to enable some of these tools is to open a new Terminal and type “sudo raspi-config”.  Once this menu appears, navigate to “Advanced Options”, this is where you can drill down into SSH and/or VNC and enable/disable these services.

Now that we have a working Raspberry Pi we can start adding all of the other components to it.   In part 2 of this Blog we will go over all of the components and how it all comes together.

Basics of the Raspberry Pi – Part 1
Part 2 – How it all works 
Part 3 – Turning a light on and off