7-segment Display Using Arduino Uno R3 (2024)

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- Arduino Uno board * 1

- USB cable * 1

- 7-segment display (Common Cathode) *1

- Resistor (220Ω) * 8

- Breadboard * 1

- Jumper wires

A 7-segment display is an 8-shaped component which packages 7 LEDs. Each LED is called a segment – when energized, one segment forms part of a numeral (both decimal and hexadecimal) to be displayed. An additional 8th LED is sometimes used within the same package thus allowing the indication of a decimal point (DP) when two or more 7-segment displays are connected together to display numbers greater than ten.

Each of the LEDs in the display is given a positional
segment with one of its connection pins led out from the rectangular plastic package. These LED pins are labeled from "a" through to "g" representing each individual LED. The other LED pins are connected together forming a common pin. So by forward biasing the appropriate pins of the LED segments in a particular order, some segments will brighten and others stay dim, thus showing the corresponding character on the display.

The common pin of the display generally tells its type. There are two types of pin connection: a pin of connected cathodes and one of connected anodes, indicating Common Cathode (CC) and Common Anode (CA). As the name suggests, a CC display has all the cathodes of the 7 LEDs connected when a CA display has all the anodes of the 7 segments connected.

Common Cathode 7-Segment Display

In a common cathode display, the cathodes of all the LED segments are connected to the logic "0" or ground. Then an individual segment (a-g) is energized by a "HIGH", or logic "1" signal via a current limiting resistor to forward bias the anode of the segment.

Common Anode 7-Segment
Display

In a common anode display, the anodes of all the LED segments are connected to the logic "1". Then an individual segment (a-g) is energized by a ground, logic "0" or "LOW" signal via a current limiting resistor to the cathode of the segment.

In this experiment, connect each of pin a-g of the 7-Segment Display to one 220ohm current limiting resistor respectively and then to pin 4–11. GND connects to GND. By programming, we can set one or several of pin4-11 as High level to light up the corresponding LED(s).

Step 1:

Build the circuit.

Step 2:

Download the code from https://github.com/primerobotics/Arduino

Step 3:

Upload the sketch to the Arduino Uno board

Click the Upload icon to upload the code to the control board.

If "Done uploading" appears at
the bottom of the window, it means the sketch has been successfully uploaded.

You should now see the 7-segment display from 0 to 9 and then A to F, back and forth.

//7-Segment
Display
//You should nowsee the 7-segment display cycle from 0 to F
//Email:info@primerobotics.in
//Website:www.primerobotics.in
const int a=7; //aof 7-segment attach to digital pin 7
const int b=6; //bof 7-segment attach to digital pin 6
const int c=5; //cof 7-segment attach to digital pin 5
const int d=11;//dof 7-segment attach to digital pin 11
const int e=10;//eof 7-segment attach to digital pin 10
const int f=8;//fof 7-segment attach to digital pin 8
const int g=9;//gof 7-segment attach to digital pin 9
const intdp=4;//dp of 7-segment attach to digital pin 4
void setup()
{
See Also
In-Depth: How Seven Segment Display Works & Interface with ArduinoArduino - TM1637 4-Digit 7-Segment Display | Arduino TutorialInterfacing 7 Segment Display with ArduinoSegment Display Tutorial for Arduino, ESP8266 and ESP32
 //loop over thisPin from 4 to 11 and set themall to output
 for(int thisPin = 4;thisPin <=11;thisPin++)
 {
 pinMode(thisPin,OUTPUT);
 }
 digitalWrite(dp,LOW);//turn the dp of the7-segment off 
}
void loop()
{
 digital_1();//diaplay 1 to the 7-segment
 delay(1000);//wait for a second
 digital_2();//diaplay 2 to the 7-segment
 delay(1000); //wait for a second
 digital_3();//diaplay 3 to the 7-segment
 delay(1000); //wait for a second
 digital_4();//diaplay 4 to the 7-segment
 delay(1000); //wait for a second
 digital_5();//diaplay 5 to the 7-segment
 delay(1000); //wait for a second
 digital_6();//diaplay 6 to the 7-segment
 delay(1000); //wait for a second
 digital_7();//diaplay 7 to the 7-segment
 delay(1000); //wait for a second
 digital_8();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_9();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_A();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_b();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_C();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_d();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_E();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
 digital_F();//diaplay 8 to the 7-segment
 delay(1000); //wait for a second
}
void digital_1(void)//diaplay 1 to the 7-segment
{
 digitalWrite(c,HIGH);//turn the c of the7-segment on
 digitalWrite(b,HIGH);//turn the b of the7-segment on
 for(int j = 7;j <= 11;j++)//turn off theothers
 digitalWrite(j,LOW);
}
voiddigital_2(void) //diaplay 2 to the 7-segment
{
 digitalWrite(b,HIGH);
 digitalWrite(a,HIGH);
 for(int j = 9;j <= 11;j++)
 digitalWrite(j,HIGH);
 digitalWrite(c,LOW);
 digitalWrite(f,LOW);
}
See Also
How to Display any Character on a 7 Segment LED Display
voiddigital_3(void) //diaplay 3 to the 7-segment
{
 unsigned char j;
 digitalWrite(g,HIGH);
 digitalWrite(d,HIGH);
 for(j=5;j<=7;j++)
 digitalWrite(j,HIGH);
 digitalWrite(f,LOW);
 digitalWrite(e,LOW);
}
voiddigital_4(void) //diaplay 4 to the 7-segment
{
 digitalWrite(c,HIGH);
 digitalWrite(b,HIGH);
 digitalWrite(f,HIGH);
 digitalWrite(g,HIGH);
 digitalWrite(a,LOW);
 digitalWrite(e,LOW);
 digitalWrite(d,LOW);
}
voiddigital_5(void) //diaplay 5 to the 7-segment
{
 unsigned char j;
 for(j = 7;j <= 9;j++)
 digitalWrite(j,HIGH);
 digitalWrite(c,HIGH);
 digitalWrite(d,HIGH);
 digitalWrite(b,LOW);
 digitalWrite(e,LOW);
}
voiddigital_6(void) //diaplay 6 to the 7-segment
{
 unsigned char j;
 for(j = 7;j <= 11;j++)
 digitalWrite(j,HIGH);
 digitalWrite(c,HIGH);
 digitalWrite(b,LOW);
}
void digital_7(void)//diaplay 7 to the 7-segment
{
 unsigned char j;
 for(j = 5;j <= 7;j++)
 digitalWrite(j,HIGH);
 for(j = 8;j <= 11;j++)
 digitalWrite(j,LOW);
}
voiddigital_8(void) //diaplay 8 to the 7-segment
{
 unsigned char j;
 for(j = 5;j <=11;j++)
 digitalWrite(j,HIGH);
}
voiddigital_9(void) //diaplay 9 to the 7-segment
{
 unsigned char j;
 for(j = 5;j <=9;j++)
 digitalWrite(j,HIGH);
 digitalWrite(d,LOW);
 digitalWrite(e,LOW);
}
voiddigital_A(void) //diaplay A to the 7-segment
{
 unsigned char j;
 for(j = 5;j <=10;j++)
 digitalWrite(j,HIGH);
 digitalWrite(d,LOW);
}
voiddigital_b(void) //diaplay b to the 7-segment
{
 unsigned char j;
 for(j = 7;j <=11;j++)
 digitalWrite(j,HIGH);
 digitalWrite(a,LOW);
 digitalWrite(b,LOW);
}
voiddigital_C(void) //diaplay C to the 7-segment
{
 digitalWrite(a,HIGH);
 digitalWrite(b,LOW);
 digitalWrite(c,LOW);
 digitalWrite(d,HIGH);
 digitalWrite(e,HIGH);
 digitalWrite(f,HIGH);
 digitalWrite(g,LOW);
}
voiddigital_d(void) //diaplay d to the 7-segment
{
 unsigned char j;
 digitalWrite(a,LOW);
 digitalWrite(f,LOW);
 digitalWrite(b,HIGH);
 digitalWrite(c,HIGH);
 digitalWrite(j,HIGH);
 for(j = 9;j <=11;j++)
 digitalWrite(j,HIGH);
}
voiddigital_E(void) //diaplay E to the 7-segment
{
 unsigned char j;
 digitalWrite(b,LOW);
 digitalWrite(c,LOW);
 for(j = 7;j <=11;j++)
 digitalWrite(j,HIGH);
}
voiddigital_F(void) //diaplay F to the 7-segment
{
 unsigned char j;
 digitalWrite(b,LOW);
 digitalWrite(c,LOW);
 digitalWrite(d,LOW);
 for(j = 7;j <=10;j++)
 digitalWrite(j,HIGH);
}