How to code a 4 Digit 7 segment display using Arduino?

Posted on May 21, 2022February 23, 2023 by Rolan Gaspar Pereira

The 4 digit 7 segment display in an intermediate level project. This project is mainly focused on how to connect the 4 digit 7 segment display with the Arduino. Once you have learnt the connection and the logic of working. Nobody can stop you from reprogramming the 4 digit 7 segment display.

To get started we will need an Arduino (Uno or whichever one you have that would not make a difference). But ideally as the number of pins increase on our Arduino boards the capability is higher and better projects can be built.

Don’t know Arduino yet? Click here to learn about the Pins and other ports available on it.

Things Needed

4 digit 7 segment display
Arduino Uno
Breadboard
Jumper cables
Resistors x 4 (200Ω)

Circuit Diagram

Code

Please download the SevSeg.h library before running the code. Click here!

#include <SevSeg.h>

int pinA = 11;int pinB = 7;int pinC = 4;int pinD = 2;
int pinE = 1;int pinF = 10;int pinG = 5;
int pinDP = 3;int D1 = 12;int D2 = 9;int D3 = 8; int D4 = 6;

void setup() {//set all segments & digits as outputs
pinMode(pinA, OUTPUT);
pinMode(pinB, OUTPUT);
pinMode(pinC, OUTPUT);
pinMode(pinD, OUTPUT);
pinMode(pinE, OUTPUT);
pinMode(pinF, OUTPUT);
pinMode(pinG, OUTPUT);
pinMode(pinDP, OUTPUT);
pinMode(D1, OUTPUT);
pinMode(D2, OUTPUT);
pinMode(D3, OUTPUT);
pinMode(D4, OUTPUT);
}

void loop() {
  
  digit1();zero();delay(500);
  digit2();one();delay(500);
  digit3();two();delay(500);
  digit4();three();delay(500);
  digit3();four();delay(500);
  digit2();five();delay(500);
  digit1();six();delay(500);
  digit2();seven();delay(500);
  digit3();eight();delay(500);
  digit4();nine();delay(500);
 
  all4Digits();
  allNumbers();

}


//functions representing numbers 0-9
void zero(){
digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, LOW);
digitalWrite(pinE, LOW);
digitalWrite(pinF, LOW);
digitalWrite(pinG, HIGH);
  }

  void one(){
digitalWrite(pinA, HIGH);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, HIGH);
digitalWrite(pinE, HIGH);
digitalWrite(pinF, HIGH);
digitalWrite(pinG, HIGH);
}

void two(){
  digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, HIGH);
digitalWrite(pinD, LOW);
digitalWrite(pinE, LOW);
digitalWrite(pinF, HIGH);
digitalWrite(pinG, LOW);
  }
  
  void three(){
    digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, LOW);
digitalWrite(pinE, HIGH);
digitalWrite(pinF, HIGH);
digitalWrite(pinG, LOW);
    }
    
  void four(){
    digitalWrite(pinA, HIGH);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, HIGH);
digitalWrite(pinE, HIGH);
digitalWrite(pinF, LOW);
digitalWrite(pinG, LOW);
    }
    
  void five(){
    digitalWrite(pinA, LOW);
digitalWrite(pinB, HIGH);
digitalWrite(pinC, LOW);
digitalWrite(pinD, LOW);
digitalWrite(pinE, HIGH);
digitalWrite(pinF, LOW);
digitalWrite(pinG, LOW);
    }
    
  void six(){
    digitalWrite(pinA, LOW);
digitalWrite(pinB, HIGH);
digitalWrite(pinC, LOW);
digitalWrite(pinD, LOW);
digitalWrite(pinE, LOW);
digitalWrite(pinF, LOW);
digitalWrite(pinG, LOW);
    }
    
  void seven(){
    digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, HIGH);
digitalWrite(pinE, HIGH);
digitalWrite(pinF, HIGH);
digitalWrite(pinG, HIGH);
    }
    
  void eight(){
    digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, LOW);
digitalWrite(pinE, LOW);
digitalWrite(pinF, LOW);
digitalWrite(pinG, LOW);
    }
    
  void nine(){
    digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, HIGH);
digitalWrite(pinE, HIGH);
digitalWrite(pinF, LOW);
digitalWrite(pinG, LOW);
    }

    void allNumbers(){
one();delay(500);
two();delay(500);
three();delay(500);
four();delay(500);
five();delay(500);
six();delay(500);
seven();delay(500);
eight();delay(500);
nine();delay(500);
      }

  void turnOffAllSegments(){
          digitalWrite(pinA, LOW);
digitalWrite(pinB, LOW);
digitalWrite(pinC, LOW);
digitalWrite(pinD, LOW);
digitalWrite(pinE, LOW);
digitalWrite(pinF, LOW);
digitalWrite(pinG, LOW);
          }


    //functions to select individual digits on the display
    void digit1(){
      digitalWrite(D1, HIGH);
digitalWrite(D2, LOW);
digitalWrite(D3, LOW);
digitalWrite(D4, LOW);
      }
      
    void digit2(){
      digitalWrite(D1, LOW);
digitalWrite(D2, HIGH);
digitalWrite(D3, LOW);
digitalWrite(D4, LOW);
      }
      
    void digit3(){
      digitalWrite(D1, LOW);
digitalWrite(D2, LOW);
digitalWrite(D3, HIGH);
digitalWrite(D4, LOW);
      }
      
    void digit4(){
      digitalWrite(D1, LOW);
digitalWrite(D2, LOW);
digitalWrite(D3, LOW);
digitalWrite(D4, HIGH);
      }

      void all4Digits(){
        digitalWrite(D1, HIGH);
digitalWrite(D2, HIGH);
digitalWrite(D3, HIGH);
digitalWrite(D4, HIGH);
        }

20 thoughts on “How to code a 4 Digit 7 segment display using Arduino?”

Leeam Benter says:

December 11, 2022 at 1:14 am

It says SevSeg.h no such file or directory. that what it all says.

Reply
electronics simplified says:

December 11, 2022 at 7:01 pm

Above the code the header file is linked. Please add the header files before using the code.

Reply
1. Sam says:
  
  June 5, 2023 at 9:09 pm
  
  How to add? I`m beginner. Please help with more info as 12 years old like me.
  
  Reply
Leeam Benter says:

December 12, 2022 at 3:33 am

Resolved, thanks for the help.

Reply
Markie Morris says:

January 21, 2023 at 8:50 am

How do You make the 7-segment countdown at least three digits?

Reply
Markie Morris says:

January 21, 2023 at 8:50 am

How do You make the 7-segment countdown at least three digits?

Reply
Hassan Sardar says:

April 6, 2023 at 10:17 pm

I ended up having a 16-pin 7-segment display. Will the code above work on it?

Reply
1. electronics simplified says:
  
  April 7, 2023 at 2:05 am
  
  Actually the same code won’t work right away.
  
  Reply
  1. Hassan Sardar says:
    
    April 11, 2023 at 8:46 pm
    
    Thank you for your help anyway. I have looked at the pinout diagram of my display and rearranged the cables accordingly so that the numbers are displayed correctly.
    One more question – how do I get a number with 2 digits or more (e.g., 16) to show on the display without having to alternate between each digit?
    
    Reply
  2. Hassan Sardar says:
    
    April 11, 2023 at 8:46 pm
    
    Thank you for your help anyway. I have looked at the pinout diagram of my display and rearranged the cables accordingly so that the numbers are displayed correctly.
    One more question – how do I get a number with 2 digits or more (e.g., 16) to show on the display without having to alternate between each digit?
    
    Reply
    1. Hassan Sardar says:
      
      April 11, 2023 at 8:47 pm
      
      Sorry if I clicked on the Post Comment button twice – it was an accident.
      
      Reply
      1. electronics simplified says:
        
        April 12, 2023 at 2:03 am
        
        You need to create separate functions to display two digits.
    2. OKStempel says:
      
      August 4, 2023 at 9:56 pm
      
      I got around the issue by implementing a very small delay, such as this:
      void loop() {
      digit4();
      one();
      delay(4);
      digit3();
      six();
      delay(4);
      }
      It’s a bit of a drawback that if you try to display all four different numbers, the LEDs get dimmer, but with only two digits you shouldn’t notice too much of a difference. Hope this helps 🙂
      
      Reply
Lennard S. says:

June 6, 2023 at 1:53 am

Does anyone know a code for this setup to create a working clock with it?

Reply
1. OKStempel says:
  
  August 4, 2023 at 11:19 pm
  
  I wanted to do the same thing and wrote the following, but I had some problems with the source code. I guess it’s because I’m using a different 7-segment display, but I had to change all the HIGHs to LOWs and LOWs to HIGHs, so if the original code works with your display, you would probably need to change that back again. Also, the E-Segment – the one that’s connected to the first pin – didn’t turn off at all, so I plugged it into the 13th pin. Nevertheless, now it works : )
  #include
  
  int pinA = 11;
  int pinB = 7;
  int pinC = 4;
  int pinD = 2;
  int pinE = 13; // I changed this pin from 1 to 13, since my first pin was always on HIGH – no idea why
  int pinF = 10;
  int pinG = 5;
  int pinDP = 3;
  int D1 = 12;
  int D2 = 9;
  int D3 = 8;
  int D4 = 6;
  
  // Variables
  int minCount;
  int tenMinCount;
  int hourCount;
  int tenHourCount;
  int timer;
  
  void setup()
  {
  Serial.begin(9600);
  pinMode(pinA, OUTPUT);
  pinMode(pinB, OUTPUT);
  pinMode(pinC, OUTPUT);
  pinMode(pinD, OUTPUT);
  pinMode(pinE, OUTPUT);
  pinMode(pinF, OUTPUT);
  pinMode(pinG, OUTPUT);
  pinMode(pinDP, OUTPUT);
  pinMode(D1, OUTPUT);
  pinMode(D2, OUTPUT);
  pinMode(D3, OUTPUT);
  pinMode(D4, OUTPUT);
  minCount = 0; // Here you can input where the minute-segment should start (0-9)
  tenMinCount = 0; // Here you can input where the ten-minute-segment should start (0-5)
  hourCount = 0; // Here you can input where the hour-segment should start (0-9 if tenHourCount (249*60)) // I tested the clock by displaying seconds instead of minutes, so if you want to test it too, just delete the *60
  {
  ClockCounter();
  timer = 0;
  }
  
  }
  
  void ClockCounter()
  {
  
  minCount++;
  if (minCount > 9) {
  minCount = 0;
  tenMinCount++;
  if (tenMinCount > 5)
  {
  tenMinCount = 0;
  hourCount++;
  if (hourCount > 9 && tenHourCount != 2)
  {
  hourCount = 0;
  tenHourCount++;
  }
  else if (hourCount > 3 && tenHourCount == 2)
  {
  hourCount = 0;
  tenHourCount = 0;
  
  }
  }
  }
  Serial.println(minCount);
  Serial.println(tenMinCount);
  Serial.println(hourCount);
  Serial.println(tenHourCount);
  }
  
  void minDisplay()
  {
  digit4();
  if (minCount == 0)
  {
  zero();
  }
  else if (minCount == 1)
  {
  one();
  }
  else if (minCount == 2)
  {
  two();
  }
  else if (minCount == 3)
  {
  three();
  }
  else if (minCount == 4)
  {
  four();
  }
  else if (minCount == 5)
  {
  five();
  }
  else if (minCount == 6)
  {
  six();
  }
  else if (minCount == 7)
  {
  seven();
  }
  else if (minCount == 8)
  {
  eight();
  }
  else if (minCount == 9)
  {
  nine();
  }
  }
  
  void tenMinDisplay()
  {
  digit3();
  if (tenMinCount == 0)
  {
  zero();
  }
  else if (tenMinCount == 1)
  {
  one();
  }
  else if (tenMinCount == 2)
  {
  two();
  }
  else if (tenMinCount == 3)
  {
  three();
  }
  else if (tenMinCount == 4)
  {
  four();
  }
  else if (tenMinCount == 5)
  {
  five();
  }
  }
  
  void hourDisplay()
  {
  digit2();
  digitalWrite(pinDP, HIGH);
  if (hourCount == 0)
  {
  zero();
  }
  else if (hourCount == 1)
  {
  one();
  }
  else if (hourCount == 2)
  {
  two();
  }
  else if (hourCount == 3)
  {
  three();
  }
  else if (hourCount == 4)
  {
  four();
  }
  else if (hourCount == 5)
  {
  five();
  }
  else if (hourCount == 6)
  {
  six();
  }
  else if (hourCount == 7)
  {
  seven();
  }
  else if (hourCount == 8)
  {
  eight();
  }
  else if (hourCount == 9)
  {
  nine();
  }
  }
  
  void tenHourDisplay()
  {
  digit1();
  digitalWrite(pinDP, LOW);
  if (tenHourCount == 0)
  {
  zero();
  }
  else if (tenHourCount == 1)
  {
  one();
  }
  else if (tenHourCount == 2)
  {
  two();
  }
  }
  
  //functions representing numbers 0-9
  void zero() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, LOW);
  }
  
  void one() {
  digitalWrite(pinA, LOW);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, LOW);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, LOW);
  digitalWrite(pinG, LOW);
  }
  
  void two() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, LOW);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, LOW);
  digitalWrite(pinG, HIGH);
  }
  
  void three() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, LOW);
  digitalWrite(pinG, HIGH);
  }
  
  void four() {
  digitalWrite(pinA, LOW);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, LOW);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
  }
  
  void five() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, LOW);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
  }
  
  void six() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, LOW);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
  }
  
  void seven() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, LOW);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, LOW);
  digitalWrite(pinG, LOW);
  }
  
  void eight() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
  }
  
  void nine() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinB, HIGH);
  digitalWrite(pinC, HIGH);
  digitalWrite(pinD, LOW);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
  }
  
  void digit1() {
  digitalWrite(D1, LOW);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, HIGH);
  digitalWrite(D4, HIGH);
  }
  
  void digit2() {
  digitalWrite(D1, HIGH);
  digitalWrite(D2, LOW);
  digitalWrite(D3, HIGH);
  digitalWrite(D4, HIGH);
  }
  
  void digit3() {
  digitalWrite(D1, HIGH);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, LOW);
  digitalWrite(D4, HIGH);
  }
  
  void digit4() {
  digitalWrite(D1, HIGH);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, HIGH);
  digitalWrite(D4, LOW);
  }
  
  Reply
  1. OKStempel says:
    
    August 4, 2023 at 11:21 pm
    
    Oh, wow, sorry for this wall of text. I didn’t realize it would be this long.
    
    Reply
  2. Shaun says:
    
    August 6, 2023 at 10:56 am
    
    Using your code im getting a compilation error: exit status 1. Any idea how to fix? thanks 🙂
    
    Reply
  3. Shaun says:
    
    August 6, 2023 at 10:56 am
    
    Using your code im getting a compilation error: exit status 1. Any idea how to fix? thanks 🙂
    
    Reply
  4. Shaun says:
    
    August 7, 2023 at 6:00 am
    
    adding an empty Loop at the end had gotten rid of the error but the clock still doesn’t work
    
    Reply