Large LED Clock Using Arduino

Hello everyone! I’m a high school student with limited experience in circuits, Arduino, and programming, and this project was a big learning journey for me. It’s largely inspired by this Instructables guide: https://www.instructables.com/Big-auto-dim-room-clock-using-arduino-and-WS2811/. I originally chose this build for my Capstone project after learning that a student had successfully completed it years ago, but the clock had since stopped working. That made me curious enough to take on the challenge myself.

Along the way, I ran into plenty of obstacles: troubleshooting circuit issues, dealing with uncooperative Arduinos, and pushing through some frustrating soldering sessions. Despite all that, I learned a tremendous amount and genuinely enjoyed the process. While I wasn’t able to fully complete the project within my school deadline, I wanted to share what I discovered in hopes of making things a bit easier for others who are just getting started with projects like this.

Everything listed here will be safe and reliable. However, you can purchase cheaper alternatives—just keep in mind that they may not work as intended and could be less reliable. I will list everything I used for my project, but you can find more affordable options, such as Chinese clones of the Arduino or cheaper soldering irons.

I’ve included everything you’ll need in an Amazon cart (not including the Arduino), so you can go in and adjust it to your preference. I selected higher-quality components, but if you’d rather save money, eBay is also a great place to look. (Keep in mind some stuff may be out of stock, look for alternatives that work just as well.)

Physical Supplies:

Arduino Nano ($31.85) - https://store.arduino.cc/products/arduino-nano?queryID=undefined

Breadboard ($4.59) - Local Walmart or my Amazon cart

Jumper Wire Kit and Pins ($17.98) - Amazon cart

Buck Converter ($7.99) - Amazon cart

WS2811 LEDs ($14.99) - Amazon cart

Double-Sided Adhesive Tape ($5.99) - Amazon cart

Solder/Soldering Tools ($24.98) - Amazon cart

Mini USB Cable For Arduino ($5.99) - Amazon cart

Cardboard (Free!) - You likely already have some

Frosted / Acrylic Plexi-Glass (29 IN x 10 IN)

Wooden Frame (34 IN x 15 IN) with interior being 10.5 IN x 29.5 IN

Amazon cart - ($82.51)

Total Cost - ($114.36)

Amazon Cart - https://www.amazon.com/cart?ref_=sw_gtc

Potential Circuitry Needed:

Capacitors

Resistors

Transistors

Light Dependent Resistor

Real-Time Clock Module

Software and Code:

You will need to install the Arduino IDE software- https://www.arduino.cc/en/software/

Inside the software install the FastLED library by Daniel Garcia:

1. Open Arduino IDE Software
2. Click Tools
3. Manage Libraries
4. Search "FastLED"
5. Install

That should be all you need for this project.

Next we need to set up the Arduino. Make sure it is plugged in using a power and data transferring cable, when you plug it in check device manager to see if your computer is recognizing it. it should be under Ports (COM & LPT). Next, be sure the IDE software is open, go to tools, board, Arduino AVR boards, and select the Nano. Then select your port below, and your processor. If it is a cheap Arduino you may have to select the old bootloader, but try the normal one first. If you want to make sure your Arduino can run code, go to file, examples, 0.1Basics, and select blink. upload and run the code and you should see a light on your Nano blinking about once a second.

I have the code attached below.

First off, as previously mentioned, I have hit the deadline for completing the project itself, so only the first number is soldered. It is the same process all the way through though.

The cardboard I am using is 29 IN x 10 IN.

As you can see, this follows a classic alarm clock style. There are 7 LEDs per segment, plus one in the center, totaling 29 LEDs (if my math is correct). This is why the code references 29 LEDs—each one is individually programmed to display the time properly. When soldering, be sure everything is properly aligned (12V–12V, DO–DIN, GND–GND).

Another important note—these LEDs have arrows on them, so make sure they are all facing the correct direction in sequential order. You’ll also notice that the LEDs are labeled DO → DIN (Data Out to Data In). This is where the code comes into play, as the data line ultimately connects back to the Arduino.

This was probably the most difficult part of the project for me. Since I’m still learning how circuits and Arduino wiring work, I mostly followed the wiring layout from the original project guide here:

https://www.instructables.com/Big-auto-dim-room-clock-using-arduino-and-WS2811/

The original guide does not go into a lot of detail about every connection, so some of this process involved trial and error, testing components, and troubleshooting issues as they came up.

Challenges I Encountered:

1. One of the biggest challenges I faced was getting the LEDs to function correctly through the circuit. Although the strip was receiving the full 12V supply, the LEDs would not illuminate properly when connected through the Arduino and breadboard setup. To troubleshoot this, I tested the LED strip separately using direct power, and only the first four LEDs lit up. I’m still unsure whether the issue was caused by a faulty LED strip or an error somewhere in my wiring or configuration, but this was by far the most significant problem I encountered throughout the project.

1. Another issue I discovered was that the Arduino Nano has very little protection against overvoltage. This makes working on a breadboard especially difficult, since even a small wiring mistake can accidentally send too much voltage to the board and potentially damage it. To avoid this, I used a buck converter to step the voltage down from 12V to approximately 4.9V before powering the Arduino.

A few important things I learned:

1. Double-check the direction of the WS2811 LEDs before soldering
2. Make sure all grounds (GND) are connected together
3. Test small sections before soldering everything permanently
4. Be careful with power connections, especially when using 12V LEDs with an Arduino

This project remains unfinished, resulting in this half-done Instructables, however this was a part of my school assignment, and the project itself was a fun learning experience. I learned a lot about how breadboards work, circuits, and Arduino, and I hope I was some help for you to complete this project, or at least learn a bit and have fun like I did :)