Published October 22, 2018 © GPL3+

Create a 7-Segment Display!

A 7-segment display with one digit.

BeginnerFull instructions provided58,033

Things used in this project

Hardware components

Arduino UNO

Common-Anode 7-segment display

I used a 5611BH

Resistor 221 ohm

Jumper wires (generic)

Story

My 7-segment display has its common pins (COM) connected to the +5V pin.

If a pin turns off, the corresponding segment will turn on. It's because when the pin is on, the voltage difference between the pin and the +5V is 0. It is the same if the +5V was replaced by 0V. We can't connect the COM to the GND because the LEDs are like diodes so they wouldn't light up at all.

The LEDs are like diodes so they won't light up if they have their anode connected to the GND.

Code

Code

void setup()
{
  init();
  /*your setup code here*/
}

void loop()
{
  /*
   * your loop code here
   *
   * use display(num, dp) to display num (0123456789ABCDEF)
   * and the dot (if dp).
   *
   * you can turn off all the leds by writing display().
   */
}

void init()
{
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
}

void display(int n=-1, boolean dp)
{
  digitalWrite(9, !dp);
  if(num == 0)
  {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 1);
  } else if(num == 1) {
    digitalWrite(2, 1);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 1);
    digitalWrite(6, 1);
    digitalWrite(7, 1);
    digitalWrite(8, 1);
  } else if(num == 2) {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 1);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 1);
    digitalWrite(8, 0);
  } else if(num == 3) {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 1);
    digitalWrite(7, 1);
    digitalWrite(8, 0);
  } else if(num == 4) {
    digitalWrite(2, 1);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 1);
    digitalWrite(6, 1);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 5) {
    digitalWrite(2, 0);
    digitalWrite(3, 1);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 1);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 6) {
    digitalWrite(2, 0);
    digitalWrite(3, 1);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 7) {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 1);
    digitalWrite(6, 1);
    digitalWrite(7, 1);
    digitalWrite(8, 1);
  } else if(num == 8) {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 9) {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 1);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 10) {
    digitalWrite(2, 0);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 1);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 11) {
    digitalWrite(2, 1);
    digitalWrite(3, 1);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 12) {
    digitalWrite(2, 0);
    digitalWrite(3, 1);
    digitalWrite(4, 1);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 1);
  } else if(num == 13) {
    digitalWrite(2, 1);
    digitalWrite(3, 0);
    digitalWrite(4, 0);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 1);
    digitalWrite(8, 0);
  } else if(num == 14) {
    digitalWrite(2, 0);
    digitalWrite(3, 1);
    digitalWrite(4, 1);
    digitalWrite(5, 0);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else if(num == 15) {
    digitalWrite(2, 0);
    digitalWrite(3, 1);
    digitalWrite(4, 1);
    digitalWrite(5, 1);
    digitalWrite(6, 0);
    digitalWrite(7, 0);
    digitalWrite(8, 0);
  } else {
    digitalWrite(2, 1);
    digitalWrite(3, 1);
    digitalWrite(4, 1);
    digitalWrite(5, 1);
    digitalWrite(6, 1);
    digitalWrite(7, 1);
    digitalWrite(8, 1);
  }
}