How to control a Dual 7 Segment Display in Arduino + Protues

Question

How can I display different numbers in a dual 7 segment with arduino and proteus?

This is my setup:

void setup() {
  pinMode(13,OUTPUT); //a
  pinMode(12,OUTPUT); //b
  pinMode(11,OUTPUT); //c
  pinMode(10,OUTPUT); //d 
  pinMode(9,OUTPUT);  //e
  pinMode(8,OUTPUT);  //f
  pinMode(7,OUTPUT);  //g

  pinMode(6,OUTPUT);  //power 1 (left)
  pinMode(5,OUTPUT);  //power 2 (left)
}

I use this code (in void loop) to display the number 0 in the 7 segment:

  digitalWrite(6, 0);  //power 1 (left)  
  digitalWrite(5, 0);  //power 2 (left)

  digitalWrite(13, HIGH);
  digitalWrite(12, HIGH);
  digitalWrite(11, HIGH);
  digitalWrite(10, HIGH);
  digitalWrite(9, HIGH);
  digitalWrite(8, HIGH);
  digitalWrite(7, LOW);

If I simulate this in proteus I got this output:

If I add another number like 8:

  digitalWrite(13, HIGH);
  digitalWrite(12, HIGH);
  digitalWrite(11, HIGH);
  digitalWrite(10, HIGH);
  digitalWrite(9, HIGH);
  digitalWrite(8, HIGH);
  digitalWrite(7, HIGH);

this will be the output:

The code will just go 0 and 8 on both of the 7segments.

I want it to display 0 on the right and eight on the left but I dont know how to control this dual 7 segment. I want to create a countdown timer, and I have not found any tutorials about it, the tutorials were 2 7 segments in the countdown, not a dual 7 segment display.

Note: I am not using any registers in this project.

Answer 1

The pins 1 and 2 are used to address each one of the seven segments. You need to sink pin 1 to the ground and supplying the value you want to display in the first seven segment then switch to the other by sinking pin 2 to the ground and supplying the value you want to display. This has to happen very fast so human eye won't notice it.

Refer to this circuit

You can use a library that saves you from all of this.

Download the library from here

To install it, open the Arduino IDE, go to Sketch > Include Library > Add .ZIP Library, then select the SevSeg ZIP file that you downloaded.

Then try the following code it should display "80"

#include "SevSeg.h"
SevSeg sevseg; 

void setup(){
  byte numDigits = 2;
  byte digitPins[] = {6, 5};
  byte segmentPins[] = {13, 12, 11, 10, 9, 8, 7, 4};

  bool resistorsOnSegments = true; 
  bool updateWithDelaysIn = true;
  byte hardwareConfig = COMMON_CATHODE; 
  sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments);
  sevseg.setBrightness(90);
}

void loop(){
    sevseg.setNumber(80, 1);
    sevseg.refreshDisplay(); 
}