Chapter 4. Project 3 – LED Cube

If you have successfully implemented the last two projects, you will have noticed that there is very little or no soldering involved. However, I would say you haven't worked on electronics if you haven't done some intense soldering and burnt your hands. In this chapter, you will get introduced to soldering in detail. You will also understand how to create a 4*4*4 LED cube using an Arduino UNO board. You will learn about the following:

• Introduction to soldering

• Designing an LED cube

• Programming a 4*4*4 LED cube

Getting started with soldering

Soldering is the process of making a sound electrical and mechanical joint between certain metals by joining them with a soft solder. This is an alloy of lead and tin with a low melting point. The joint is heated to the correct temperature by a soldering iron. Effective soldering requires good heat transfer from the iron to the components to be soldered. The longer heat is applied, the greater the risk of heat damage to the wire or component, so it's important to get the job wrapped up quickly.

What you will need

Before you proceed further with the next section of the chapter, make sure you have the following items with you and have got yourself familiarized with the tools:

• Soldering iron

• Basic stand

• Solder desoldering pump

• Cardboard

The following image is for your quick reference so that you will get a rough idea of soldering tools. One thing to remember is that soldering tools vary from place to place, so don't worry if your tools don't look exactly the same. An...

Designing an LED cube

As mentioned before, the main focus of this chapter is on soldering. In this section, you will learn how to design an LED cube, which will have intense soldering, and creative elements like LED control and Arduino programming.

Required components

Before getting into the cube design, make sure you have following components for this project:

• Arduino UNO

• 64 LEDs: You can use any color LED. Although 64 LEDs are required for this project, I would recommend you to buy at least 100 LEDs in case some LEDs get burned during the soldering process.

• 16 resistors: These must be appropriate to your LEDs. If you are not sure which resistor to purchase, get 500 Ω/1k Ω resistors.

• Connecting wires

• A printed circuit board

• Thermocol

• Soldering iron and solder wire

Principle behind the design

Before you read this section, make sure you have the listed components or have already ordered them. This section is the most important part of this chapter as it explains the key principle behind the project...

Programming a 4*4*4 LED cube

Having done the hard part of soldering, let's get into Arduino connection and programming. Before connecting the positive leads, connect four negative layers to Arduino analog I/O ports A2 (bottom layer) through A5 (top layer). After that, 16 LED control pins needs to be connected to the Arduino board. Connect the first 14 pins to Arduino digital I/O ports 0 to 13. The remaining pins 15 and 16 need to be connected to Analog pins A0 and A1. See the following diagram for connection reference:

There are a few things that you should understand before programming your cube:

• To address a single LED use a plane (layer) number 0–3, and an LED pin number 0–15. Turn the plane to LOW output (negative leg) and the LED pin number to HIGH (positive leg) to activate the LED.

• Before activating a single LED, ensure all other planes are off by setting them to HIGH output. If you don't do this, the whole column of LEDs will light up instead of a single LED.

Now you are all set to start...

Summary

So far in this book, the focus was more on understanding Arduino programming and less about electronics and soldering. If you reached the end of this chapter, this means you have learnt the very important skill that is soldering. Having understood soldering and Arduino programming, you can now bring your own ideas into reality/prototype. Share your prototype and experience on social media using hashtag #ArduinoBLINK.

Having gained sound knowledge of Arduino programming and soldering, in the next chapter you will learn about sound visualization and how to use different sensors with Arduino.