2 Digit Seven Segment Display




About: Electronics hobbyist

Most of the newbies are confused about using two or more seven segment displays, here is an instructable showing the implementation of the same with a microcontroller.

This is possible by virtue of high switching speed of LED and high of the microcontroller.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Components Required

1. Seven segment display.

2. 220 Ohm resistors.

3. Jumper wire.

4. Breadboard.

5. Arduino UNO.

Step 2: Pin Configuration

Please note down that I have never used the pin notation as per Arduino, rather the port wise pins have been mentioned wiz; PORTC, PORTD, etc.

The pin configuration of Arduino UNO, seven segment display(both Common Anode & Common Cathode) is as shown.

Step 3: Circuit:

Make connection as shown in the schematic diagram.

Step 4: Source Code

The source code can be obtained from my GitHub profile. Click here

Be the First to Share


    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest

    12 Discussions


    Reply 1 year ago

    Nope, they are the common cathode type.


    Reply 1 year ago

    They are the common cathode type, we can apply the same technique to the common anode as well, but there will be a small revision in logic. I'll try making it and update the instructable.


    1 year ago

    OK, n00b alert... I was interested in constructing a small compact elctronic scoring device. Let's say I have 2IN X 2IN X 2IN space, to accommodate a pair of 2-digit displays, the arduino UNO, toggle/up-down numeric control, battery power etc. Is this even remotely possible?

    2 replies

    Reply 1 year ago

    Yes, you can use the RF transceivers or a Bluetooth module or a Wifi module. It depends on the range you desire to control.


    Reply 1 year ago

    Assuming the dimensions of space to be 2X2X2 inches. Since the UNO board is bigger in size, you should make your custom PCB to meet your requirements. Else, using other boards like Nano and Micro should do the job.

    And to control the score remotely, we should even provide some means of connectivity, be it a Bluetooth or WiFi. My suggestion is to use ESP12 based microcontroller it has WiFi connectivity.


    1 year ago


    Thanks for the guide!

    FYI: I found one error in "Step3: Circuit diagram". In the picture you have drawn the control wire for pin 8 and 9 to the same 7-seg display "vcc-pin". One of those needs to go to the second 7-seg display.

    1 reply

    Reply 1 year ago

    Yeah, Thanks for the information.


    Question 1 year ago on Introduction

    I there,

    I am an enthusiast, and enjoyed watching your project!! How can your software be optimized to display actual values of some kind?? Like for instance temperature, or any other process variable?? Can an additional display be added??

    I would appreciate your feedback.


    Emile Steyn

    1 answer

    Reply 1 year ago

    the variable containing the numeric value needs to be sampled into the digits, and these variables need to be called to display now and then very often so that the values are displayed. And yeah additional display can be added, the only difference is the number of select lines increases.


    2 years ago

    Yea, but can you make the seven segment displays do that exact same thing without the Arduino Micro-controller? We used to do that with building our own oscillator and circuitry. Makes you learn more about how things really work. Nice project either way. I am glad to see younger folks getting into electronics even if it is always a Arduino controller circuit.

    1 reply

    Reply 2 years ago

    Thank you, we are here to learn unknown concepts of course. I'll be glad to learn your concept too. Could you please share it with us??