How a 7 Segment Display Works


This tutorial will introduce you to a 7 segment display as a beginner's guide.


We see these displays every day, and rarely think about how they work. Commonly, you will see the displays on your digital alarm clock, elevator numbers, gas station price changer signs, stove top, and on microwave oven display screens.

Learning how to use them is then really handy for any mini application!



The first thing we must understand is how to identify and turn on 1 segment of a 7 segment display.

On the back side of the display, we notice 10 pins. You will need to identify PIN1 in order to properly assign VCC (power) and Gnd (ground) to the pins. This information is found on the technical specifications sheet, also known as the "data sheet". For our example, you can locate the data sheet in the product details page of the single digit 7 segment.

PIN1 is identified in this image with a red circle. In order to "turn on" (illuminate) each segment, the segment must have power and ground.


Identifying Pins

When we identify PIN1, we can also identify its relationship to the letter on the front/display side of the 7 segment. In this example, we see PIN1 = E

If we give power to PIN1, we can expect the segment to illuminate (of course the segment must be grounded properly). In order to properly ground the segment, we must identify the ground pins. Looking at the data sheet, we notice pins 3 & 8 are ground.


Ok, so we identified pins 3 & 8 are ground, now we must identify their location on the backside of the segment. This image below shows pins 1 through 5.


We can also identify the pin numbers to the letters on the front/display side of the 7 segment.

 PIN1 = E
 PIN2 = D
 PIN4 = C
 PIN5 = DP (Decimal Point)

The illustration below shows us pins 6 through 10.


We can also identify the pin numbers to the letters on the front/display side of the 7 segment (pins 6 through 10).

 PIN6 = B 
 PIN7 = A 
 PIN8 = GND 
 PIN9 = F 
 PIN10 = G 

Now we understand how to identify the display pins and their corresponding segment, and we are ready to learn how to light them up!

This article was published by the Jaycon team. Learn more about how we can take your product design and hardware idea to the next level here.