LED Clock




Please find my Arduino clock project using the UNO board and Adafruit's Neopixels. It is a work in progress, so please be patient with my tutorial.....It will become more detailed as I get some time up my sleeve. The code and wiring details are to be found on GitHub (see links ahead).

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: Parts Required.

x1 10K resistor

x1 430R resistor

x1 LDR (light dependent resistor)

x1 12 LED Neopixel ring (Adafruit)

x1 60 LED Neopixel ring (Adafruit) - note that the ring comes in four parts

x1 RTC DS1307 (real time clock)

x1 Arduino UNO R3 board

x1 breadboard


Step 2: The Hardware Layout (As Per Fritzing Design).


You can download the Fritzing diagram to help assist in the wiring of the project. Note that the resistor is a 10K one.

Step 3: The Code.


The code can be found at GitHub for download. As I get some time, I will discuss some of the code in more detail.

Step 4: Videos of It Working.

Not the best of videos, but I thought it would be nice to show it working. I will upload better ones demonstrating some of the features.

Step 5: The RTC.

The RTC DS1307 was used to help keep the correct time. Refer to the Fritzing diagram for correct wiring.

Step 6: The Separate Rings.

The small ring (12 LEDs) is used for the hour hand and the larger ring (60 LEDs) is used for the minutes and seconds hands. An LDR (Light dependent resistor) has been incorporated into the build to adjust the brightness of both rings. These rings can be purchased from the Adafruit website. Note that the 60 LED ring comes in four parts and needs to be soldered together.

Step 7: The UNO Board.

I used the UNO board, but others work just as well.

Step 8: An Artistic Finish to the Project.

A laser cut case was used to complete the project.

Step 9: Night Effect.

Note that the light sensitive resistor makes the LEDs less bright in the dark.

Be the First to Share


    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest

    9 Discussions


    1 year ago

    Hi Steven, Have you tried to add two bottoms to set the time manually? Do you think if it would be hard to do it?


    1 year ago

    Hi Steven, could you help me identify the resistors in the ciruit? CapedBandit asked about the 430 ohm, and I get the LDR, but in the final circuit, what is next to the RTC? Is it 10k? Sorry, I am an absolute beginner with not much electrical background. Thank you

    3 replies

    4 years ago

    Hi CapedBandit, I added the 430 ohm resistors as I read somewhere that it may save the neo pixels when you turn on the power. Steve.


    4 years ago on Introduction

    I have all the parts, but I see in your completed pictures, you have resistors in line with the input to the rings. There is no mention of this anywhere. What are the ohms and what are they for?


    5 years ago

    Thank you brmarcum, maybe we can improve on the code? The 60 LED needs to be soldered together at the back, but there are specific instructions on the Line in and Line out. You need to leave the final set unsoldered for the wires to attach to. Only Line in is required unless you want to link several 60 LED rings.


    5 years ago

    Well, looks like you beat me to it. I have something similar in mind, but I didn't know about the 60 LED ring before. Nice project.