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.
- Plugged our 40 Pin Cable into our Raspberry Pi
- Plugged the other end of the 40 Pin Cable into our GPIO Extension Board
- 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:
- 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.
- On the same line the resistor connects to, plug in one end of your LED light
- 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.