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4 layers150.3 × 47.5 mmBoluder clock replacement, the printed circuit board in 3D

This project provides the source code and design files for the Boulder Clock Replacement Board, designed as a direct drop-in replacement for the original Boulder Clock hardware.

Size
150.3 × 47.5 mm
Copper layers
4
Thickness
1.61 mm
Parts
225
Nets
272
Pads
770
Tracks, vias
1,876, 223
Pours
5
Routed
Yes
KiCad
KiCad 9.0 (file 20241229)
Created
10 Mar 2025
Updated
9 Oct 2025

Overview

Boluder clock replacement is an open-source printed circuit board by mickdassive, from the mickdassive/boulder_clock_replacent_bord repository on GitHub. It is a 4-layer board of 150.3 × 47.5 mm with 225 parts on 272 nets, routed with 1,876 tracks and 223 vias.

It is built around the ESP-12F, HV9150K6-G and TPS63031DSKR, with the CD4028BNSR, PI4IOE5V6416LEX and BSS127H6327XTSA2 among its other parts. Its parts include 88 resistors, 61 transistors, 30 capacitors, 12 ICs and 3 switches. It belongs with the lEDs and displays boards and the ESP8266 boards of this library.

Main components

8

README

README.md

Boulder Clock Replacement Board

This project provides the source code and design files for the Boulder Clock Replacement Board, designed as a direct drop-in replacement for the original Boulder Clock hardware. The board is fully compatible with existing clock circuitry—no additional wiring or modifications are required.

Features

  • Drop-in replacement for Boulder Clock boards—no extra wiring needed
  • Open-source hardware and software design (GPLv3 license)
  • Improved time accuracy
  • WiFi configuration via web interface (WiFi Manager)
  • Adjustable GMT offset, DST settings, and 12/24 hour mode
  • Easy-to-follow assembly instructions

Getting Started

Prerequisites

  • Basic knowledge of electronics and soldering
  • Appropriate tools for PCB assembly
  • PlatformIO installed for firmware upload

Installation

  1. Clone the Repository

    bash
    git clone https://github.com/mickdassive/boulder_clock_replacent_bord.git
    cd boulder_clock_replacent_bord
  2. Review Design Files

    • Check the hardware/ or pcb/ directory for PCB layout and schematics.
    • Review the firmware/ directory for microcontroller code.
  3. Build and Assemble

    • Order the PCB using the provided Gerber files.
    • Source and solder components as listed in the bill of materials (BOM).
  4. Upload Firmware Using PlatformIO

    • Open the project in PlatformIO IDE (recommended for VS Code).

    • Connect your microcontroller board to your computer via USB.

    • In PlatformIO, select the correct environment for your board (see platformio.ini).

    • Build and upload the firmware:

      text
      pio run --target upload

      Or use the "Upload" button in the PlatformIO IDE.

    • The firmware is pre-configured for the Boulder Clock Replacement Board. No code changes or configuration should be necessary for standard operation.

WiFi Manager Configuration

The board features a built-in WiFi Manager interface for easy configuration of time and connectivity settings:

  1. Initial Setup

    • After powering on the board, if no WiFi credentials are stored, it will automatically start in WiFi Access Point mode.
    • Connect to the WiFi network broadcast by the board (SSID will be " Boulder Clock fwv x.x" or similar).
  2. Access the Web Interface

    • Open a web browser and navigate to 192.168.4.1 to access the configuration portal.
  3. Configure WiFi and Clock Settings

    • Enter your local WiFi credentials.
    • Set the following options in the web interface:
      • GMT Offset: Adjust the clock’s time zone offset from GMT (e.g., +1, -5, etc.).
      • 12/24 Hour Mode: Choose between 12-hour (AM/PM) or 24-hour display.
      • Daylight Saving Time (DST): Enable or disable automatic DST adjustment.
  4. Save Settings

    • Save your changes and allow the board to reboot. It will connect to your WiFi and keep time according to your chosen settings.

Usage

  • Install the assembled board in place of the original Boulder Clock board.
  • No extra wiring is needed—simply drop in as a replacement.
  • Power on and configure settings via the WiFi Manager if needed.

Repository Structure

text
hardware/      # PCB schematics, layouts, and Gerber files
firmware/      # PlatformIO project, microcontroller code
platformio.ini # PlatformIO configuration file
LICENSE        # GPLv3 license information
README.md      # This file

Contributing

Contributions are welcome! If you have suggestions, improvements, or bug fixes, please submit a pull request or open an issue.

License

This project is licensed under the GNU General Public License v3.0. See the LICENSE file for details.

Acknowledgments

  • Inspired by the original Boulder Clock hardware

For additional help or questions, please open an issue in this repository.

Parts

225
QtyValueFootprintReferences
603K3Resistor_SMD:R_0603_1608MetricR14, R15, R16, R17, R18, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R31 +44
60BSS127H6327XTSA2Package_TO_SOT_SMD:SOT-23Q1, Q2, Q10, Q11, Q12, Q13, Q14, Q15, Q16, Q17, Q18, Q19, Q20, Q22, Q23, Q24 +44
150uF1Capacitor_SMD:C_0603_1608MetricC3, C4, C6, C7, C8, C9, C12, C13, C14, C16, C19, C21, C23, C24, C27
1010KResistor_SMD:R_0603_1608MetricR1, R2, R4, R5, R6, R7, R8, R11, R12, R13
1010uFCapacitor_SMD:C_0603_1608MetricC1, C2, C10, C11, C15, C17, C18, C20, C22, C29
10TestPointTestPoint:TestPoint_Pad_D1.0mmTP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8, TP9, TP10
680KResistor_SMD:R_0603_1608MetricR19, R30, R50, R61, R72, R83
6CD4028BNSRPackage_SO:SOP-16_4.4x10.4mm_P1.27mmU4, U5, U7, U8, U9, U10
6~boulder:boulder nixieNT1, NT2, NT3, NT4, NT5, NT6
32K2Resistor_SMD:R_0603_1608MetricR9, R10, R43
3MountingHoleMountingHole:MountingHole_2.7mm_M2.5H1, H2, H3
21KResistor_SMD:R_0603_1608MetricR3, R39
25K1Resistor_SMD:R_0603_1608MetricR37, R38
2PI4IOE5V6416LEXboulder:TSSOP-24_4.4x7.8mm_P0.65mmU1, U2
11MResistor_SMD:R_0603_1608MetricR42
11uFCapacitor_SMD:C_0603_1608MetricC26
122uFCapacitor_SMD:C_0603_1608MetricC5
1250BXC22MEFC10X16 22uFCapacitor_THT:CP_Radial_D8.0mm_P5.00mmC28
132KHz768boulder:XTAL_SC32S-7PF20PPM_EPSY1
1330RResistor_SMD:R_0603_1608MetricR36
136-2997-NDboulder:2997_KEYBT1
147KResistor_SMD:R_0603_1608MetricR41
14uF7Capacitor_SMD:C_0603_1608MetricC25
1BRL3225T1R5M 1uH5Inductor_SMD:L_1210_3225MetricL1
1C1206X104K251T 0uF1Capacitor_SMD:C_1206_3216MetricC30
1ESP-12FRF_Module:ESP-12EU6
1FQD12N20LTM-F085PPackage_TO_SOT_SMD:TO-252-2Q21
1G***kibuzzard-67CF4B2Fkibuzzard-67CF4B2F
1G***kibuzzard-67CF4A67kibuzzard-67CF4A67
1G***kibuzzard-67CF4A53kibuzzard-67CF4A53
1G***kibuzzard-67CF4A70kibuzzard-67CF4A70
1HV9150Package_DFN_QFN:QFN-16-1EP_3x3mm_P0.5mm_EP1.7x1.7mmU11
1MINUSButton_Switch_THT:SW_Tactile_SKHH_AngledSW3
1NHP140SFT3Gboulder:NHP140SF-DD1
1NS10145T470MNVV 47uHInductor_SMD:L_Taiyo-Yuden_NR-10050_9.8x10.0mmL2
1PCF8523TK/1,118Package_SON:HVSON-8-1EP_4x4mm_P0.8mm_EP2.2x3.1mmU3
1PLUSButton_Switch_THT:SW_Tactile_SKHH_AngledSW2
1PROG_PORTConnector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_VerticalJ1
1PVG3A102C01R00 1Kboulder:POT_PVG3A_BRNR40
1PVG3A502C01R00 5Kboulder:POT_PVG3A_BRNR44
1SETButton_Switch_THT:SW_Tactile_SKHH_AngledSW1
1SolderJumper_2_OpenJumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mmJP1
1TPS63031DSKRboulder:TPS63031DSKRU12
1USB4515-GF-Aboulder:USB4515-GF-A_GCTJ2

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Questions

How big is the Boluder clock replacement PCB?

It measures 150.3 × 47.5 mm and has 4 copper layers, 1.61 mm thick.

What parts does the Boluder clock replacement use?

225 parts, built around the ESP-12F, HV9150K6-G, TPS63031DSKR and CD4028BNSR. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Boluder clock replacement KiCad files?

From the mickdassive/boulder_clock_replacent_bord repository on GitHub, at the commit this page was made from: the board is hardware/boluder clock replacement.kicad_pcb and its schematic hardware/DIGITS.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Boluder clock replacement design in my own project?

Its repository states no licence, so its author keeps all rights: ask mickdassive before reusing the design.