A 7-segment display is commonly used in electronic display devices for decimal numbers from 0 to 9 and in some cases, basic characters. The use of light-emitting diodes (LEDs) in seven-segment displays made it more popular, whereas of late liquid crystal displays (LCD) have also come into use.
Electronic devices like microwave ovens, calculators, washing machines, radios, digital clocks, etc. to display numeric information are the most common applications. Let’s take a look at the seven display pinout to have a better understanding.
7-Segment Display Pinout
A seven-segment display is made of seven different illuminating segments. These are arranged in a way to form numbers and characters by displaying different combinations of segments.
The binary information is displayed using these seven segments. LED is a P-N junction diode that emits energy in the form of light, different from a standard P-N junction diode which emits in the form of heat.
Whereas LCD uses liquid crystal properties for displaying and does not emit light directly. These LEDs or LCDs are used to display the required numeral or alphabet.
Seven Segment Display Types
There are basically 2 types of seven-segment LED displays:
1. Common Anode 7 Segment Display:
All the Negative terminals (Anode) of all the 8 LEDs are connected together. All the positive terminals are left alone.
2. Common Cathode 7 Segment Display:
All the positive terminals (Cathode) of all the 8 LEDs are connected together. All the negative thermals are left alone.
Seven-Segment Display Working
Seven-segment devices are generally made up of LEDs. These LEDs will glow when they are forward-biased. The intensity of the LEDs depends on the forward current.
So, a sufficient forward current has to be provided to these LEDs to glow with full intensity. This is provided by the driver and is applied to the seven segments.
7-Segment Display Codes
The below table shows the 0-9 codes for the seven-segment LED display.
| Number | g f e d c b a | Hex code |
| 0 | 1000000 | C0 |
| 1 | 1111001 | F9 |
| 2 | 0100100 | A4 |
| 3 | 0110000 | B0 |
| 4 | 0011001 | 99 |
| 5 | 0010010 | 92 |
| 6 | 0000010 | 82 |
| 7 | 1111000 | F8 |
| 8 | 0000000 | 80 |
| 9 | 0010000 | 90 |
Table: Display numbers on a seven-segment display in common anode configuration
Things change for common cathode configuration.
| Number | g f e d c b a | Hex Code |
| 0 | 0111111 | 3F |
| 1 | 0000110 | 06 |
| 2 | 1011011 | 5B |
| 3 | 1001111 | 4F |
| 4 | 1100110 | 66 |
| 5 | 1101101 | 6D |
| 6 | 1111101 | 7D |
| 7 | 0000111 | 07 |
| 8 | 1111111 | 7F |
| 9 | 1001111 | 4F |
Table: Display numbers on a seven-segment display in common cathode configuration
Below we are interfacing a 7-segment display to Arduino UNO for reference.
7-Segment Display-based Projects
For more technical information, you can refer to the 7-Segment Display Datasheet.
FAQs:
What is a 7-segment display?
A 7-segment display is a visual indicator used to display numerical digits and some characters. It consists of seven LED segments arranged in a specific pattern, with each segment representing one of the digits from 0 to 9.
How does a 7-segment display unit work?
Each segment in a 7-segment display is individually controlled to turn on or off. By selectively activating specific segments, you can form the desired digit or character. For example, to display the digit ‘5’, you would activate the segments necessary to create its visual representation.
How do I get a 7-segment display?
You can obtain a 7-segment display from electronics suppliers, online marketplaces, or local electronic component stores. They are available in various sizes, colors, and configurations to suit your project’s requirements.
What is the objective of a 7-segment display?
The main objective of a 7-segment display is to provide a simple and visually recognizable way to display numerical information. It’s commonly used in digital clocks, calculators, digital meters, and other applications where numerical data needs to be presented.
How does a 7-segment display work?
Each segment in a 7-segment display corresponds to a specific LED or segment, with the arrangement designed to form the digits 0 to 9 when activated in different combinations. By turning on the required segments, you create the desired number or character on the display.
Are seven-segment displays still in production?
Yes, seven-segment displays are still in production and widely used in various applications. They offer a cost-effective and straightforward solution for displaying numeric information and are often integrated into digital devices and electronic projects.
This article was first published on 29 December 2016 and recently updated on August 2023.
In common anode, All the Positive terminals (Anode) of all the 8 LEDs are connected together. All the negative terminals are left alone.
Common Cathode: All the negative terminals (Cathode) of all the 8 LEDs are connected together. All the positive thermals are left alone.
For the cathode 9’s hexcode will be 6f instead of 4f.
Can someone in charge of this page fix this?
You say: “Types of 7 segments
There are basically 2 types of 7 segment LED display.
Common Anode: All the Negative terminals (cathode) of all the 8 LEDs are connected together. All the positive terminals are left alone.
Common Cathode: All the positive terminals (anode) of all the 8 LEDs are connected together. All the negative thermals are left alone.”
This is backwards.