Seven segment display is an electronic component, which is designed using 7 Led lights arranged in “8” structure. this used to display the numbers from 0 to 9 and some character’s. this Component is mainly found in digital clock, induction cooker and calculators. This article shares the seven segment display pinout and Truth table and additional information’s.
What is a Seven Segment Display?
7-segment display is a seven LED arranged electronic component used to display the numbers and some character’s. The seven LED are named as a, b, c, d, e, f, g letters. The pinout also represents based on the name of LED.
Seven Segment Display Pinout
7 Segment common Cathode Pinout
Pinout Configuration for common cathode Display
| Pin No. | Segment Name | Function |
|---|---|---|
| 1 | e | Segment Control |
| 2 | d | Segment Control |
| 3 | COM | Ground (GND) |
| 4 | c | Segment Control |
| 5 | dp | Decimal Point |
| 6 | b | Segment Control |
| 7 | a | Segment Control |
| 8 | COM | Ground (GND) |
| 9 | f | Segment Control |
| 10 | g | Segment Control |
7 Segment Common Anode Pinout
Pinout Configuration for common anode Display
| Pin No. | Segment Name | Function |
|---|---|---|
| 1 | e | Segment Control |
| 2 | d | Segment Control |
| 3 | COM | VCC (+) |
| 4 | c | Segment Control |
| 5 | dp | Decimal Point |
| 6 | b | Segment Control |
| 7 | a | Segment Control |
| 8 | COM | VCC (+) |
| 9 | f | Segment Control |
| 10 | g | Segment Control |
Types of 7 Segment Display
- Common cathode
- Common Anode
Common Anode vs Common Cathode
| Feature | Common Anode | Common Cathode |
|---|---|---|
| Common Pin Connection | VCC or + supply voltage | GND |
| Logic to Turn ON | LOW (0) | HIGH (1) |
| Current Flow Direction | VCC > Segment > Controller | Controller > Segment > GND |
| Control Method | Current Sinking | Current Sourcing |
| Microcontroller Compatibility | Preferred for many MCUs | Easy for beginners |
| Circuit Complexity | Slightly complex | Simple |
| Power Consumption | Efficient in multiplexing | Slightly higher |
| Usage | Multiplexed displays, embedded systems | Basic circuits, learning projects |
7 Segment Display Truth Table
The seven segment display showing the number from 0-9 and some special character’s. For number showing specific LED lights are become high and the other in Low. This combination of LED on and OFF makes the particular number visible on the display.
Truth table is the binary code sent to the pins of seven segment display to show the numbers for human readable. The Truth table for common cathode display is given below. For cathode 1 = ON, 0 = OFF, for anode display 1 = OFF, 0 = ON
| Digit | BCD (D C B A) | a | b | c | d | e | f | g |
|---|---|---|---|---|---|---|---|---|
| 0 | 0 0 0 0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 |
| 1 | 0 0 0 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 |
| 2 | 0 0 1 0 | 1 | 1 | 0 | 1 | 1 | 0 | 1 |
| 3 | 0 0 1 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 |
| 4 | 0 1 0 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 |
| 5 | 0 1 0 1 | 1 | 0 | 1 | 1 | 0 | 1 | 1 |
| 6 | 0 1 1 0 | 1 | 0 | 1 | 1 | 1 | 1 | 1 |
| 7 | 0 1 1 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
| 8 | 1 0 0 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 9 | 1 0 0 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 |
Working Principle
The working of seven segment display is activation of required lights inside the display for showing the number or characters. The 8 like structure arranged LED make combination of ON and OFF to create the numbers from 0 to 9.
- Digit 0 : Activating LED lights of a, b, c, d, e and f g is turn off.
- Digit 1: Activating LEDs of b and c others are OFF.
Applications
- Digital clocks.
- Bench power supply.
- Induction coocktop.
- Counters.
- Measurement devices.
Frequently Asked Questions (FAQ)
The CC means Common Cathode display, which are all negative pins of the 7 LED connected together. In CA (common Anode) display all positive of 7 LED is connected together.
In common cathode display all cathode pins are connected to negative as common and other seven 8 pins are using as connection for a, b, c, d ,e, f, g and dp. For common anode display the common connection is anode side of the LED.
Seven segment or 7 seg display consist of seven LED which is arranged in 8 like structure to display the numbers from 0-9 and some special characters. The numbers showing on the display is based on activation of different LED to from the numbers as visible.
Their are two types of 7 segment display available, which are common cathode and common anode display.
Because this display consist of 7 LED lights which are used to show the numbering by turn ON and OFF the corresponding LED’s. Each segments of the LED is marked as a to g. For decimal point a dp connection is also given.
It is depending on your configuration. If you want to reduce the LED power consumption or reduce brightness of LED’s you can use resistors in each of the pins labeled from a to g and dp.
To test seven segment display, use a 1.5v battery takes the positive and negative supply from it. If the display is common cathode connect battery negative to com pin and positive pins touch all a to g pins to see corresponding LEDs are glowing.
Dp is dot point, each display has this point to represent the point needed values.
