2cm Height 7 Segments 6 Digits AVR Clock With 4 Digits Thermometer




Posted in TechnologyMicrocontrollers

Introduction: 2cm Height 7 Segments 6 Digits AVR Clock With 4 Digits Thermometer

This project is explaining how to create yourself a 6 digits 7 segments clock with AVR microcontroller

Step 1: Prepare the Parts for This Project

We need to prepare a parts for this project,

6x 7 Segments Common Anode

6x PNP transistors for driver, I used 2N3906

6x 1K 1/WW resistors

1x Module ATMEGA128

1x NTC resistor 10K

1x 10K resistor 1/4W

2x Push button for adjusting the hour and minute


1x Atmel studio

Step 2: The Segment Code

I have written the segment code for this project,

Please have a look on the picture in this step....

That's how I drive each seven segment with PNP transistor, it's cheap but more than enough for driving 8 segments

Step 3: The Firmware and MCU Selection

You're going to need at least 15 I/O from your MCU for this project,

In my case I used ATMEGA128, but you can use ATTiny2313,ATMEGA8,ATMEGA16 and others family of AVR 8-bits

I'm using interrupt and timer to increase second, you can upgrade to a calendar as well if you one, quite simple and straight forward.

Hex file is included if you want to use ATMEGA128

Here's the setup for my timer and ISR :

{ seconds++;

if(seconds == 60) {

seconds = 0;

minutes++; }

if(minutes == 60)

{ minutes = 0; hours++; }

if(hours > 23) hours = 0; }

Step 4: The Demo in Video

Let's watch this clock working on video



    • Casting Contest

      Casting Contest
    • Microcontroller Contest

      Microcontroller Contest
    • Woodworking Contest

      Woodworking Contest

    We have a be nice policy.
    Please be positive and constructive.




    How to repeat this design if the author hasn't given the scheme of connections

    It's easy to embed videos in Instructables, more information here: