How to do Wiring LED, Digital Inputs to Arduino UNO R3 Board

We would like to start with the first step while building the project and there are few learning objectives I would like to cover. In this section we will learn how to wire simple components using a prototyping board, how to read digital input from simple switch device, use pull up or pull down resistors.

How to write digital output to LED component and learn to handle switch bouncing. We will do all of that while developing a software sketch using global and local variables the setup and loop functions, building a new function and at the end this sketch will control the all the Arduino platform.

Arduino Project Building Block

The following diagram is the project building blocks for this step:

1. In the middle we have the Arduino board, connected to 6 LEDs as output, on the left side we will use two pushbuttons as input.
2. The first pushbutton will be used to test that all LEDs are working by turning them ON/OFF.
3. The second push button is to run a short animation wave across the 6 LEDs.
4. That’s the overall plan and let’s start by wiring the LEDs to the Arduino board.

Usage Of Led In Arduino Project And How To Wire Them

LEDs are one of the most-used components in many projects and as you probably know, led stands for light-emitting diode. Like all diodes components, led allows current to flow in only one direction, so LEDs are polarized components, meaning we need to carefully connect them in the right direction.. The positive lead is called the "anode", and the negative lead is called the "cathode" another way to find that is to look on the length of the two leads.

The shorter lead is the cathode, meaning the Negative lead. Now, because current flows from positive to negative, the anode of the led should be connected to the current source meaning the 5v digital signal in this case, and the cathode should be connected to ground.

Another thing that is super important is to use resistor as current limiter. A resistor must be placed in series on either side of the led.

Now, as resistors are not polarized, we do not need to worry about their orientation. Now, the logic is very simply the larger the resistor value, the more it will restricts the flow of current and the dimmer the led will glows, in our scenario, we are using a 220ω resistors. Looking the diagram here, each led is connect on one side to the ground and the other side to a resistor that is connected to specific digital pin in the arduino platform

This is a complete circuit and in total we have like 6 separated circuits for 6 leds. Later in our sketch we will setup all the 6 pins to be output and turn the leds on and off, using specific software commands. You can download complete circuit diagram of Arduino UNO circuit in PDF from here. Please watch this video below to understand it better.


Download Important Files of This Project

Please download this important file that we have made, for you, in this project. These files are hosted in Google drive and Media fire storage servers. Please download from below.

Download 8.1 Step - 1

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Download 8.2 Step - 2

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Download 10.1 Step - 1B

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