Display (Output) Arduino Project

updated 21 April 2022

This is a simple project in Arduino that uses the breadboard, the Arduino UNO Board, the 7-Segment Display and basic programming. Take note, there are several ways to do this same project but we'll focus on one.

The Arduino UNO Board

The Arduino UNO Board is the basic board for beginners doing projects in Arduino.

As from the previous project, without a microcontroller, your only control is through an external switch. And you are just limited to that.

The microcontroller will enable you to program electronic components so that you can build digital devices that you want to build.

The Digital Pins

The digital pins are the very first to be encountered because they can be used by components in several ways. They will be connected to the terminals of electronic components. There are 14 Digital Pins in Arduino UNO Board.

The GND

The GND is the floating ground to complete the circuit. Remember, in an electrical setup the earth ground is used extensively. In electronics, it's the convenience to use a floating ground.

The BreadBoard

The breadboard is your convenience for you to simply put things in place. Plus, it provides connections either horizontally or vertically for further ease. Because of this, you avoid overlapping wires: the metal strip at the bottom provides the connection.

The 7-Segment Display

To not complicate things, we just use one 7-Segment Display for the output. Remember, computer monitors' concept of display is the same: the dot-and-no-dot pattern to create a display, whether an image or letter or numbers. You can do the same thing by using LEDs to serve as pixels.

But here in our project, we want to use the 7-Segment Display as an upgrade from the basic LEDs. It's called 7-Segment Display because there are seven segments of LEDs, forming the number 8 unlighted.

The 7-Segment Display will either use cathode or anode. Make sure you got it right. It depends on your circuit design.

The Arduino Code

There are just two default functions in Arduino: void setup and void loop.

void setup is where you tell the Arduino board about the common setup just like whether a digital pin will be used as output or input.

void loop is where the Arduino board executes all the commands you put there just like digitalWrite whether high or low. HIGH means there is a voltage supplied just like turning it on through an external switch and LOW means there is no voltage supplied or there is but is too low. Voltage that is not sufficient will still be just like no voltage at all.

Project Guide

Using the TinkerCAD, here are the steps to create the project:

1. Make sure that you change the 7-Segment Display common terminal to cathode.

2. Follow the proper wiring:

   Arduino Pin	Segment Pin
   13	G
   12	F
   11	A
   10	B
   9	E
   8	D
   7	C
   6	DP

3. Close the circuit by the GND. Use a resistor that is exactly 200 ohms (left resistor when facing the screen) and 100 ohms for the other one. left: right:

4. Copy paste the program below:

   unsigned const int A = 13;
   unsigned const int B = 12;
   unsigned const int C = 11;
   unsigned const int D = 10;
   unsigned const int E = 9;
   unsigned const int F = 8;
   unsigned const int G = 7;
   unsigned const int H = 6;
   
   
   void setup(void)
   {
     pinMode(A, OUTPUT);
     pinMode(B, OUTPUT);
     pinMode(C, OUTPUT);
     pinMode(D, OUTPUT);
     pinMode(E, OUTPUT);
     pinMode(F, OUTPUT);
     pinMode(G, OUTPUT);
     pinMode(H, OUTPUT);
   }
   
   //functions to display
   //the numbers
   void displayZero(void) {
     digitalWrite(A, LOW);
     digitalWrite(B, HIGH);
     digitalWrite(C, HIGH);
     digitalWrite(D, HIGH);
     digitalWrite(E, HIGH);
     digitalWrite(F, HIGH);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displayOne(void) {
     digitalWrite(A, LOW);
     digitalWrite(B, LOW);
     digitalWrite(C, LOW);
     digitalWrite(D, HIGH);
     digitalWrite(E, LOW);
     digitalWrite(F, LOW);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displayTwo(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, LOW);
     digitalWrite(C, HIGH);
     digitalWrite(D, HIGH);
     digitalWrite(E, HIGH);
     digitalWrite(F, HIGH);
     digitalWrite(G, LOW);
     digitalWrite(H, LOW);
   }
   
   void displayThree(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, LOW);
     digitalWrite(C, HIGH);
     digitalWrite(D, HIGH);
     digitalWrite(E, LOW);
     digitalWrite(F, HIGH);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displayFour(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, HIGH);
     digitalWrite(C, LOW);
     digitalWrite(D, HIGH);
     digitalWrite(E, LOW);
     digitalWrite(F, LOW);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displayFive(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, HIGH);
     digitalWrite(C, HIGH);
     digitalWrite(D, LOW);
     digitalWrite(E, LOW);
     digitalWrite(F, HIGH);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displaySix(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, HIGH);
     digitalWrite(C, HIGH);
     digitalWrite(D, LOW);
     digitalWrite(E, HIGH);
     digitalWrite(F, HIGH);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displaySeven(void) {
     digitalWrite(A, LOW);
     digitalWrite(B, LOW);
     digitalWrite(C, HIGH);
     digitalWrite(D, HIGH);
     digitalWrite(E, LOW);
     digitalWrite(F, LOW);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displayEight(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, HIGH);
     digitalWrite(C, HIGH);
     digitalWrite(D, HIGH);
     digitalWrite(E, HIGH);
     digitalWrite(F, HIGH);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   void displayNine(void) {
     digitalWrite(A, HIGH);
     digitalWrite(B, HIGH);
     digitalWrite(C, HIGH);
     digitalWrite(D, HIGH);
     digitalWrite(E, LOW);
     digitalWrite(F, HIGH);
     digitalWrite(G, HIGH);
     digitalWrite(H, LOW);
   }
   
   //execute the codes
   //by invoking the functions
   void loop(void)
   {
   
     displayNine();
     delay(1000);
   
     displayEight();
     delay(1000);
   
     displaySeven();
     delay(1000);
   
     displaySix();
     delay(1000);
   
     displayFive();
     delay(1000);
   
     displayFour();
     delay(1000);
   
     displayThree();
     delay(1000);
   
     displayTwo();
     delay(1000);
   
     displayOne();
     delay(1000);
   
     displayZero();
     delay(1000);
   
   }
   

   The code will simply have the countdown but the individual function for a certain number can be used several times for your own version. Simply invoke the function inside the void loop.

5. Of course, simulate the program!

6. Final Version: add a border using LEDs with your own pattern of blinking or group of LEDs of your own style. Make the 7-Segment Display component display letters to form words that have significance to you. There should be at least 2 words presented and another two groups of numbers like your birth date, year you were born, significant date in your life, lucky numbers for you, etc. Explain the significance by using comments.

Finally, the actual project is here:

https://www.tinkercad.com/things/fZCbIFVaMor