Led is very basic component in the design and some time led do lot more work than just indication.
In this article we will see how to build custom designed seven segment display using led.
There are lot of variety of seven segment in the market but i choose to build my own because of i had time and many leds laying around me.

I have used Kicad tool for schematic and PCB designing.

Step 1: Required Components

For this project we will need following components

Any Arduino board from following,
Arduino Nano - https://www.banggood.in/custlink/KKGygoIaOF
Arduino Uno - https://www.banggood.in/custlink/GvmyBlZaOo
Arduino Pro Mini - https://www.banggood.in/custlink/vvGy0Lijj0
Arduino Mega2560 - https://www.banggood.in/custlink/vKGY0lioLA
LED (15 per segment x 4 Segements) = Total 60 LED's.
Resistor 220 ohm = 7 Nos
Designed PCB

Step 2: Schematic

Step 3: Working Principle in Pictorial Form

As you can see in the schematic we are using two led and one resistor for them which will limit the current.
and to turn on the two led we have to make the pin HIGH which will make the one segment ON.
Like wise as you can see in the first diagram i am making all the pins high and second diagram making all the pins as LOW.

To display number '1' : make the pins as HIGH which are connected to segments B and C.

To display number '2' : make the pins as HIGHwhich are connected to segments B, D, E, G.