Category: Make

3D Printed NeoPixel Clock

This project is for a digital clock based on NeoPixels driven by an Arduino microcontroller. One thing to note is the clock is huge! The dimensions are 43.5cm x 16cm.

Introduction

The 3D design is not mine but can be downloaded from thingyverse: 7 Segment IOT Smart Clock

The original project was based on an IOT clock controlled by an online dashboard. I didn’t need that level of sophistication so I opted to use an Arduino R4 with its internal real time clock (RTC) to keep time. This was not a great idea as it turns out, more of that later.

The project is not complete but is a working in-progress. For instance, I have not included a way to set the time without using the computer. I also want to add a method to change the colour of the digits and a way to dim the digits in dark ambient light.

Design

As already mentioned the 3D design is available on Thingyverse.

For the electronics I decided to use an Arduino microcontroller as I had experience driving NeoPixels for my model railway layout. A library is used for the NeoPixels and is available from Adafruit.

My idea was to use the Arduino R4 Nano as it has an internal RTC which can be kept active using a small 3v battery for when power is removed from the clock. This was easy to program and works as expected. That was until I noticed the clock was not very accurate. It was gaining time meaning the clock was out by minutes at the end of the day. It is well documented and not easy to fix. I could automatically reset the time each day to keep it more accurate but in the end I decided to use an external RTC. The RTC of choice was the DS3231 which I got preassembled from eBay.

Construction

Start by printing the 3D case. I used Black PLA+ for the surrounds and backs, and I used white PLA+ for the individual segments. Before assembly, I created a paper template of the segments so I could assemble the NeoPixels.

I stuck the NeoPixels to the template and soldered connections between keeping mind of the flow (NeoPixels have an input and output) connecting the output of one pair of pixels to the input of the next. I labelled the segments using the traditional 7 segment labels, a-g. On the first and last connection I had longer wires with connectors to connect to the next digit.

The digits need to be screwed together with 3mm screws and nuts. They are hidden inside. The NeoPixel digits can then be glued in place and connected to the next digit. The first digit will have connections for the Arduino and then connect to the second digit through the centre hole.

At this point I prototyped the Arduino hardware on a plug in breadboard and connected to the NeoPixels assembled in the enclosure.

Now you can assemble the Arduino on a piece of veroboard with connections for the NeoPixels and a second veroboard with the RTC. I also used a small DC-DC converter to step down the 12v adaptor I had to 5v for the Arduino.

There should be enough room to connect the Arduino to the computer for programming without removing it. When connecting to the computer I removed the connection to the NeoPixels to avoid drawing too much current from the computer.

Code

The code is split in a number of parts. First is the declaration of libraries and global variables.

/*
*
*   Copyright (c) 2026, Perry Andrews 
*   https://www.pelnet.co.uk
*   All rights reserved.
*
*   Title: NeoPixel Clock
*/

#include <Adafruit_NeoPixel.h>
#include <Wire.h>
#include <DS3231-RTC.h>

// Define the NeoPixels Arduino pin  
#define LED_PIN     6

// How many NeoPixels are attached to the Arduino
#define LED_COUNT  58

// NeoPixel brightness, 0 (min) to 255 (max)
#define BRIGHTNESS 128

// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRB);

DS3231 myRTC;

// Set these values for the RTC
byte year = 26;
byte month = 1;
byte date = 11;
byte dOW = 1;
byte hour = 21;
byte minute = 35;
byte second = 0;
byte oldhour = 24;
byte oldminute = 60;

The values assigned to the time variables is only used during the first programming. At normal startup after the RTC has been set the values are overwritten by the RTC.

Next is the setup code:

void setup() {
  
  // Start the I2C interface
  Wire.begin();

  // Set Up DS3231 RTC
  bool mode12 = false; // use 24-hour clock mode
  myRTC.setClockMode(mode12); // uploads 'true' (1) to bit 6 of register 0x02

  // Set Time - One off, comment out after first run.
  /*
  myRTC.setYear(year); // uploads 22 to register 0x06
  myRTC.setMonth(month); // uploads 1 to register 0x05
  myRTC.setDate(date); // uploads 5 to register 0x04
  myRTC.setDoW(dOW); // uploads 1 to register 0x03 (Sunday)
  myRTC.setHour(hour); // uploads 19 to register 0x02
  myRTC.setMinute(minute); // uploads 17 to register 0x01
  myRTC.setSecond(second); // uploads 42 to register 0x00
  */
    
  // Initialise LEDR, LEDG and LEDB as outputs
  pinMode(LEDR, OUTPUT);
  pinMode(LEDG, OUTPUT);
  pinMode(LEDB, OUTPUT);
  
  // Turn off all LEDs initially
  digitalWrite(LEDR, HIGH);
  digitalWrite(LEDG, HIGH);
  digitalWrite(LEDB, HIGH);

  strip.begin();           // Initialise NeoPixel
  strip.show();            // Turn OFF all pixels ASAP
  strip.setBrightness(BRIGHTNESS); // Set BRIGHTNESS

  display_digit(0,0,0);
  
  // Turn on the built-in red LED and turn off the rest
  digitalWrite(LEDR, LOW);
  digitalWrite(LEDG, HIGH);
  digitalWrite(LEDB, HIGH);
  
}

The serial interface was used for debugging but I removed from the final code.

The loop code:

void loop() {
  // put your main code here, to run repeatedly:
  bool h12;
  bool hPM;
  bool CenturyBit;
  char digitcol = 7; // White Digits

  byte date = myRTC.getDate();
  byte month = myRTC.getMonth(CenturyBit);
  byte year = myRTC.getYear();
  byte dOW = myRTC.getDoW();
  byte hour = myRTC.getHour(h12, hPM);  
  byte minute = myRTC.getMinute();
  byte second = myRTC.getSecond();

  // Display Time on NeoPixel Display
  if (hour != oldhour){
    oldhour = hour;
    display_digit(hour % 10,2,digitcol);
    hour = hour / 10;
    display_digit(hour,3,digitcol);
    //oldminute = 60;
  }
  if(minute != oldminute){
    oldminute = minute;
    display_digit(minute % 10,0,digitcol);
    minute = minute / 10;
    display_digit(minute,1,digitcol);
    display_colon(digitcol);
  }
}

Additionally there are some subroutines called in loop:

void display_colon(char col){
  uint32_t colour;
  switch(col){
    case 0:
      colour = strip.Color(0, 0, 0);  //Off
      break;
    case 1:
      colour = strip.Color(255, 0, 0);  //Red
      break;
    case 2:
      colour = strip.Color(0, 255, 0);  //Green
      break;
    case 3:
      colour = strip.Color(0, 0, 255);  //Blue
      break;
    case 4:
      colour = strip.Color(255, 255, 0);  //Yellow
      break;
    case 5:
      colour = strip.Color(255, 0, 255);  //Magenta
      break;
    case 6:
      colour = strip.Color(0, 255, 255);  //Cyan
      break;
    case 7:
      colour = strip.Color(255, 255, 255);  //White
      break;
    default:
      colour = strip.Color(0, 0, 0);  //Off
  }
  strip.setPixelColor(28, colour);
  strip.setPixelColor(29, colour);
}

void display_digit(char num, char digit, char col){
  char offset = 0;
  uint32_t colour;

  switch(digit){
    case 0:
      offset = 0;
      break;
    case 1:
      offset = 14;
      break;
    case 2:
      offset = 30;
      break;
    case 3:
      offset = 44;
      break;
    default:
      offset = 0;
      break;
  }
  switch(col){
    case 0:
      colour = strip.Color(0, 0, 0);  //Off
      break;
    case 1:
      colour = strip.Color(255, 0, 0);  //Red
      break;
    case 2:
      colour = strip.Color(0, 255, 0);  //Green
      break;
    case 3:
      colour = strip.Color(0, 0, 255);  //Blue
      break;
    case 4:
      colour = strip.Color(255, 255, 0);  //Yellow
      break;
    case 5:
      colour = strip.Color(255, 0, 255);  //Magenta
      break;
    case 6:
      colour = strip.Color(0, 255, 255);  //Cyan
      break;
    case 7:
      colour = strip.Color(255, 255, 255);  //White
      break;
    default:
      colour = strip.Color(255, 0, 0);  //Red
  }
  switch(num){
    case 0:
      strip.setPixelColor(0 + offset, colour); //a
      strip.setPixelColor(1 + offset, colour); //a
      strip.setPixelColor(2 + offset, colour); //b
      strip.setPixelColor(3 + offset, colour); //b
      strip.setPixelColor(4 + offset, colour); //c
      strip.setPixelColor(5 + offset, colour); //c
      strip.setPixelColor(6 + offset, colour); //d
      strip.setPixelColor(7 + offset, colour); //d
      strip.setPixelColor(8 + offset, colour); //e
      strip.setPixelColor(9 + offset, colour); //e
      strip.setPixelColor(10 + offset, colour); //f
      strip.setPixelColor(11 + offset, colour); //f
      strip.setPixelColor(12 + offset, strip.Color(0, 0, 0)); //g
      strip.setPixelColor(13 + offset, strip.Color(0, 0, 0)); //g
      strip.show();
      break;
    case 1:
      strip.setPixelColor(0 + offset, colour); //a
      strip.setPixelColor(1 + offset, colour); //a
      strip.setPixelColor(2 + offset, colour); //b
      strip.setPixelColor(3 + offset, colour); //b
      strip.setPixelColor(4 + offset, strip.Color(0, 0, 0)); //c
      strip.setPixelColor(5 + offset, strip.Color(0, 0, 0)); //c
      strip.setPixelColor(6 + offset, strip.Color(0, 0, 0)); //d
      strip.setPixelColor(7 + offset, strip.Color(0, 0, 0)); //d
      strip.setPixelColor(8 + offset, strip.Color(0, 0, 0)); //e
      strip.setPixelColor(9 + offset, strip.Color(0, 0, 0)); //e
      strip.setPixelColor(10 + offset, strip.Color(0, 0, 0)); //f
      strip.setPixelColor(11 + offset, strip.Color(0, 0, 0)); //f
      strip.setPixelColor(12 + offset, strip.Color(0, 0, 0)); //g
      strip.setPixelColor(13 + offset, strip.Color(0, 0, 0)); //g
      strip.show();
      break;
    case 2:
      strip.setPixelColor(0 + offset, strip.Color(0, 0, 0)); //a
      strip.setPixelColor(1 + offset, strip.Color(0, 0, 0)); //a
      strip.setPixelColor(2 + offset, colour);  //b
      strip.setPixelColor(3 + offset, colour);  //b
      strip.setPixelColor(4 + offset, colour);  //c
      strip.setPixelColor(5 + offset, colour);  //c
      strip.setPixelColor(6 + offset, strip.Color(0, 0, 0));  //d
      strip.setPixelColor(7 + offset, strip.Color(0, 0, 0));  //d
      strip.setPixelColor(8 + offset, colour);  //e
      strip.setPixelColor(9 + offset, colour);  //e
      strip.setPixelColor(10 + offset, colour); //f
      strip.setPixelColor(11 + offset, colour); //f
      strip.setPixelColor(12 + offset, colour); //g
      strip.setPixelColor(13 + offset, colour); //g
      strip.show();
      break;
    case 3:
      strip.setPixelColor(0 + offset, colour);  //a
      strip.setPixelColor(1 + offset, colour);  //a
      strip.setPixelColor(2 + offset, colour);  //b
      strip.setPixelColor(3 + offset, colour);  //b
      strip.setPixelColor(4 + offset, colour);  //c
      strip.setPixelColor(5 + offset, colour);  //c
      strip.setPixelColor(6 + offset, strip.Color(0, 0, 0));  //d
      strip.setPixelColor(7 + offset, strip.Color(0, 0, 0));  //d
      strip.setPixelColor(8 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(9 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(10 + offset, colour);  //f
      strip.setPixelColor(11 + offset, colour);  //f
      strip.setPixelColor(12 + offset, colour);  //g
      strip.setPixelColor(13 + offset, colour);  //g
      strip.show();
      break;
    case 4:
      strip.setPixelColor(0 + offset, colour);   //a
      strip.setPixelColor(1 + offset, colour);   //a
      strip.setPixelColor(2 + offset, colour);   //b
      strip.setPixelColor(3 + offset, colour);   //b
      strip.setPixelColor(4 + offset, strip.Color(0, 0, 0));  //c
      strip.setPixelColor(5 + offset, strip.Color(0, 0, 0));  //c
      strip.setPixelColor(6 + offset, colour);   //d
      strip.setPixelColor(7 + offset, colour);   //d
      strip.setPixelColor(8 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(9 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(10 + offset, strip.Color(0, 0, 0));  //f
      strip.setPixelColor(11 + offset, strip.Color(0, 0, 0));  //f
      strip.setPixelColor(12 + offset, colour);  //g
      strip.setPixelColor(13 + offset, colour);  //g
      strip.show();
      break;
    case 5:
      strip.setPixelColor(0 + offset, colour);   //a
      strip.setPixelColor(1 + offset, colour);   //a
      strip.setPixelColor(2 + offset, strip.Color(0, 0, 0));  //b
      strip.setPixelColor(3 + offset, strip.Color(0, 0, 0));  //b
      strip.setPixelColor(4 + offset, colour);   //c
      strip.setPixelColor(5 + offset, colour);   //c
      strip.setPixelColor(6 + offset, colour);   //d
      strip.setPixelColor(7 + offset, colour);   //d
      strip.setPixelColor(8 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(9 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(10 + offset, colour);  //f
      strip.setPixelColor(11 + offset, colour);  //f
      strip.setPixelColor(12 + offset, colour);  //g
      strip.setPixelColor(13 + offset, colour);  //g
      strip.show();
      break;
    case 6:
      strip.setPixelColor(0 + offset, colour);   //a
      strip.setPixelColor(1 + offset, colour);   //a
      strip.setPixelColor(2 + offset, strip.Color(0, 0, 0));  //b
      strip.setPixelColor(3 + offset, strip.Color(0, 0, 0));  //b
      strip.setPixelColor(4 + offset, colour);   //c
      strip.setPixelColor(5 + offset, colour);   //c
      strip.setPixelColor(6 + offset, colour);   //d
      strip.setPixelColor(7 + offset, colour);   //d
      strip.setPixelColor(8 + offset, colour);   //e
      strip.setPixelColor(9 + offset, colour);   //e
      strip.setPixelColor(10 + offset, colour);  //f
      strip.setPixelColor(11 + offset, colour);  //f
      strip.setPixelColor(12 + offset, colour);  //g
      strip.setPixelColor(13 + offset, colour);  //g
      strip.show();
      break;
    case 7:
      strip.setPixelColor(0 + offset, colour);   //a
      strip.setPixelColor(1 + offset, colour);   //a
      strip.setPixelColor(2 + offset, colour);   //b
      strip.setPixelColor(3 + offset, colour);   //b
      strip.setPixelColor(4 + offset, colour);   //c
      strip.setPixelColor(5 + offset, colour);   //c
      strip.setPixelColor(6 + offset, strip.Color(0, 0, 0));  //d
      strip.setPixelColor(7 + offset, strip.Color(0, 0, 0));  //d
      strip.setPixelColor(8 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(9 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(10 + offset, strip.Color(0, 0, 0));  //f
      strip.setPixelColor(11 + offset, strip.Color(0, 0, 0));  //f
      strip.setPixelColor(12 + offset, strip.Color(0, 0, 0));  //g
      strip.setPixelColor(13 + offset, strip.Color(0, 0, 0));  //g
      strip.show();
      break;
    case 8:
      strip.setPixelColor(0 + offset, colour);   //a
      strip.setPixelColor(1 + offset, colour);   //a
      strip.setPixelColor(2 + offset, colour);   //b
      strip.setPixelColor(3 + offset, colour);   //b
      strip.setPixelColor(4 + offset, colour);   //c
      strip.setPixelColor(5 + offset, colour);   //c
      strip.setPixelColor(6 + offset, colour);   //d
      strip.setPixelColor(7 + offset, colour);   //d
      strip.setPixelColor(8 + offset, colour);   //e
      strip.setPixelColor(9 + offset, colour);   //e
      strip.setPixelColor(10 + offset, colour);  //f
      strip.setPixelColor(11 + offset, colour);  //f
      strip.setPixelColor(12 + offset, colour);  //g
      strip.setPixelColor(13 + offset, colour);  //g
      strip.show();
      break;
    case 9:
      strip.setPixelColor(0 + offset, colour);   //a
      strip.setPixelColor(1 + offset, colour);   //a
      strip.setPixelColor(2 + offset, colour);   //b
      strip.setPixelColor(3 + offset, colour);   //b
      strip.setPixelColor(4 + offset, colour);   //c
      strip.setPixelColor(5 + offset, colour);   //c
      strip.setPixelColor(6 + offset, colour);   //d
      strip.setPixelColor(7 + offset, colour);   //d
      strip.setPixelColor(8 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(9 + offset, strip.Color(0, 0, 0));  //e
      strip.setPixelColor(10 + offset, colour);  //f
      strip.setPixelColor(11 + offset, colour);  //f
      strip.setPixelColor(12 + offset, colour);  //g
      strip.setPixelColor(13 + offset, colour);  //g
      strip.show();
      break;
  }
}

This is all the code used. I appreciate there is probably a better way to implement displaying a digit.

Conclusion

This is a first iteration of the project and is not complete. Also, I have not optimised the code in any way and so there could be bugs and inefficiencies in the code. However, it does work.

The following improvements will be implemented at a future date.

Light sensor to dim the brightness in dark ambient light
Buttons to set the time without using the computer
Button to change digit colours
Alternative IR remote control to set time & colour

I hope this project has been inspirational and shows you can create a project based on someone else’s shared work.

Links

7 Segment IOT Smart Clock

Adafruit NeoPixel Library

Arduino R4 Nano Manual

02/04/2026

My Webcam
Introduction

For many years I had a webcam on my website and have used different methods of making it work. It mainly consisted of a PC or Linux Computer and a USB Camera. This was overkill for a webcam, being noisy, using more power than necessary and taking up a lot of space.

When the Raspberry Pi Camera was launched I could see an immediate use to create a webcam that would overcome all of the downfalls of my current set-up. I had already been using the Raspberry Pi so adding a camera was not too much effort.

My first Webcam used the original Raspberry Pi Model B. I used Raspian and created a script to take pictures every 5 minutes. The script also uploaded them to my website. This was scheduled using cron.

Design

My latest Webcam is a Raspberry Pi 3 Model B computer with a camera and is stuck to a window with the camera pointing outside. Every 5 minutes it takes a photo with the camera and uploads it to my website. You can see the webcam in action here.

I use is Raspberry Pi OS and the webcam software is picam which can be downloaded and installed from the OS. Instructions are provided in the GitHub repository.

picam can be set up and used in a few different ways. I configured mine to take a picture and upload it to my website. Additionally I enabled the video output so I could record the live footage as a security camera. Using software such as Synology Surveillance Station you can detect motion and record video.

I also added a RGB LED as a status indicator as when running the webcam is not connected to a monitor.

Parts

You will need the following parts for this project:
- Raspberry Pi 3 Model B
- Raspberry Pi Camera Module
- MicroSD Card (16GB)
- LM2596 DC-DC Step Down Buck Convertor (eBay)
- 5MM RGB LED
- 3D Printed Case
- 20mm Round Button Suction Cup x 4
- 2.5mm Power Socket
- 12v 2A PSU with 2.5mm power plug
You also need wire and connectors for internal connections. I suggest dupont wires which can be cut and soldered on to the LED’s and Buck Convertor and the other end plugged onto the Raspberry Pi Header.

Everything is available on eBay and considering the current price of later models of Raspberry Pi opt for a used RPi 3 Model B. This has built in wireless so you don’t need to connect to a wired LAN.

Set-up

Most of the setup can be done before mounting the Raspberry Pi in a case. You can power the Raspberry Pi using the USB connector and plug the Monitor into the HDMI or Composite connector. You also need a USB keyboard.
Set up involves downloading Raspberry PI OS from the Raspberry Pi Website and copying it to the microSD card.

Once copied you need to connect the Raspberry Pi to a monitor, keyboard and power supply. Apply power and let the OS boot to the command prompt.

From the command prompt you can use the instructions provided on the picam GitHub repository to prepare the OS, download the picam binary and install it.

Construction

Print the case using a 3D printer. The case is in two parts. The base is printed using Black PTEG filament. This is less likely to warp when exposed to heat than PLA+. The top cover is printed in any colour PLA+.

Glue in the camera board with the camera through the square hole. Feed the camera ribbon cable through the thin slot so the cable comes outside the case. Screw in the buck converter and glue in the power socket in it’s small slot.

Before using the step-down buck converter you need to connect it to the power supply and set the output voltage to 5v. Failure to do this before connecting the Raspberry Pi could be disastrous.

Fit the Raspberry Pi in the case by angling the ports in the holes first and then pushing the PCB flat. Secure with 4 self tapping screws. Don’t over tighten. Insert the memory card in the slot after the board has been fitted otherwise the PCB is difficult to push flat.

Connect the Power wires, the Camera ribbon cable and finally the RGB LED wires.

Use the picture above to connect the wires. The camera ribbon camera can be folded gently to fit under the lid when it is fitted. Be careful not to trap it.

The lid is fastened with 4 x 3mm screws. Slide the 20mm suction cups into the slots and you are ready to go.

Links
02/10/2025

Category: Make

3D Printed NeoPixel Clock

Introduction

Design

Construction

Code

Conclusion

Links

My Webcam

Introduction

Design

Parts

Set-up

Construction

Links