How to Make a Simple Two 7 Segment Display using Arduino?

Most beginners are confused by the usage of two or more seven segment displays; here is an instructable demonstrating the implementation of the same using a microcontroller.

This is achievable because of the rapid switching speed of the LED and the microcontroller.

Components/Materials Needed:

• Arduino UNO R3
• Breadboard
• 2 pieces of 7 Segment Display
• 2 pieces of 220 ohms resistors
• Jumper Wires

Schematic Diagram of a Circuit

Sample Code

// 7 Segment Display Activity (0 to 99)
// By: Isaiah B. Eje

// Declare Variables
int a = 12;
int b = 13;
int c = 7;
int d = 8;
int e = 9 ;
int f = 11 ;
int g = 10;
int a2 = 5;
int b2 = 6;
int c2 = 0;
int d2 = 1;
int e2 = 2 ;
int f2 = 4 ;
int g2 = 3;
int wait = 600;

// Setup
void setup() {
 //initialize pinMode from the two 7 segment display
 pinMode(a,OUTPUT);
 pinMode(b,OUTPUT);
 pinMode(c,OUTPUT);
 pinMode(d,OUTPUT);
 pinMode(e,OUTPUT);
 pinMode(f,OUTPUT);
 pinMode(g,OUTPUT);
 pinMode(a2,OUTPUT);
 pinMode(b2,OUTPUT);
 pinMode(c2,OUTPUT);
 pinMode(d2,OUTPUT);
 pinMode(e2,OUTPUT);
 pinMode(f2,OUTPUT);
 pinMode(g2,OUTPUT);
}

// Define of the method to control the first display.
void display (int a, int b, int c, int d, int e, int f, int g)
{
 // Define for each segment one pin.
  digitalWrite (12,a);   
  digitalWrite (13,b);   
  digitalWrite (7,c);
  digitalWrite (8,d);
  digitalWrite (9,e);
  digitalWrite (11,f);
  digitalWrite (10,g);
}
// Define of the method to control the second display.
void display2 (int a, int b, int c, int d, int e, int f, int g)
{
  digitalWrite (5,a);   
  digitalWrite (6,b);   
  digitalWrite (0,c);
  digitalWrite (1,d);
  digitalWrite (2,e);
  digitalWrite (4,f);
  digitalWrite (3,g);
}

// Define of the count down method for the second display
void display2play ()
{
 // Specify as 0 the segments that we want to power on
    display2 (1,0,0,1,1,1,1); delay(wait); // 1
    display2 (0,0,1,0,0,1,0); delay(wait); // 2
    display2 (0,0,0,0,1,1,0); delay(wait); // 3
    display2 (1,0,0,1,1,0,0); delay(wait); // 4
    display2 (0,1,0,0,1,0,0); delay(wait); // 5
    display2 (0,1,0,0,0,0,0); delay(wait); // 6
    display2 (0,0,0,1,1,1,1); delay(wait); // 7
    display2 (0,0,0,0,0,0,0); delay(wait); // 8
    display2 (0,0,0,0,1,0,0); delay(wait); // 9
    display2 (0,0,0,0,0,0,1); // 0
}

//Defintion of the loop
void loop() {
  //For each number of the first display, the second one goes from 0 to 9
  //By this way we can obtain a 0 to 99 counter loop
    display (0,0,0,0,0,0,1); 
    delay(wait);
    display2play();
  
    display (1,0,0,1,1,1,1);
    delay(wait);
    display2play();
  
    display (0,0,1,0,0,1,0);
    delay(wait);
    display2play();
  
    display (0,0,0,0,1,1,0);
    delay(wait);
    display2play();
  
    display (1,0,0,1,1,0,0);
    delay(wait);
    display2play();
  
    display (0,1,0,0,1,0,0);
    delay(wait);
    display2play();
  
    display (0,1,0,0,0,0,0);
    delay(wait);
    display2play();
  
    display (0,0,0,1,1,1,1); 
    delay(wait);
    display2play();
  
    display (0,0,0,0,0,0,0);
    delay(wait);
    display2play();
  
    display (0,0,0,1,1,0,0);
    delay(wait);
    display2play();
}

sample Simulation using Tinkercad

I hope you can enjoy it!