The “Dyadnix” Two Tube Nixie Clock kit

This kit is no-longer available

(The microcontroller chip is still available in the shop)

nixie clock kit released December 2010

Over 160 of these nixie clock kits have been sold!


This is my third clock kit design. It has two Russian IN-14 Nixie tubes to display Time, Date and Temperature.

As it shows each pair of digits, the base of the tubes illuminate with any one of  7 colours, e.g. Blue for Hours, Green for Minutes.

There are many configuration options so you can adjust the display to how you like it.

It also has effects such as “slot machine” digits and even some LED effects that run when the tubes are turned off.

This design has two boards which plug-together to keep it compact without needing any tiny “surface-mount” parts.

Features  (firmware v2 released September 2011)
  • The core of the clock is a Microchip PIC18F1330 8-bit CMOS microcontroller IC. (It is programmed entirely in assembly language code for high performance).
  • Timekeeping by watch crystal or 50/60Hz mains frequency with up to 12 hours “Supercap” backup. (The timekeeping accuracy can be finely adjusted in the clock software.)
  • All clock option settings are easily adjusted using two push-buttons and are retained in the controller non-volatile memory during power-off.
  • The clock is very configurable with over 50 user settings.
  • Time, Date and Temperature digit effects.
  • 12 or 24 hour mode time display with am/pm indication.
  • Gently fading digits options.
  • Automatic DST (Daylight Saving Time) rule presets for UK,Europe,US,Australia,New Zealand & Mexico. + custom settings for other locations or future rule changes.
  • Configurable multi-colour Tube LEDs to indicate which information is being shown and other effects
  • Display brightness can be automatically dimmed or turned-off between set hours or by light sensor, ideal for night time use.
  • Manual tubes toggle on/off facility can override the automatic timed or light sensor modes.
  • Interesting LED effects for when the tubes are turned-off.
  • Adjustable LED brightness and colour.
  • UK/US Date display options and automatic leap year compensation.
  • Temperature in °C or °F using a DS18B20 digital sensor with fine accuracy adjustment.
  • Special Thermometer mode to constantly show the temperature.
  • Maximum/ Minimum temperature display.
  • Can be configured to continually show just the date (calendar mode)
  • Digit Cycling effects can be configured to run at various intervals.
  • Random effects selection.
  • Low power consumption from a 9 – 12 Volts AC or DC adaptor (Not Included).
  • The High Voltage (HV) converter shuts-down to save power if the tubes are turned-off. (When in timed or light-controlled tubes off modes).
  • Protected by a fast-blow fuse and software HV monitoring with overload shutdown.
  • Auto diagnostics for the HV soft-startup with  problem indication by  LEDs.
  • Compact design with no tiny surface-mount parts.
  • Configuration can be easily reset back to defaults if you wish.

Power supply adapter requirements:
  • A 9 – 12 Volts AC or DC power adapter (wall-wart) rated at 300-500mA is required
Power consumption:
  • Approx 2 Watts with both tubes and LEDs on.
    0.2 Watts with all tubes, LEDS and HV off.
  • PCB only – 64mm X 45mm X 1.6mm (2.52″ X 1.77″ X 0.06″)
    Height (including tubes) Approx 76mm (3″)
Timekeeping Accuracy:
  • (Un-adjusted crystal accuracy ± 1.7 seconds per day)
    Timekeeping fine-adjustment in software or mains frequency sync.
Temperature Display:
  • 0 – 125°C (the unadjusted accuracy is ± 0.5°C between 0 – 85°C )
    The displayable Fahrenheit range is 32 -199°F
Weight: (no case):
  • Approx 76 Grams (2.7oz)

You can download the user manual here

Dyadnix Clock User Manual V1
Dyadnix Clock User Manual V2

(Version 2 manual is only for clocks supplied after September 2011 with v2 firmware)

Assembly Manual

Dyadnix Assembly Manual

Circuit Description

Dyadnix Circuit description
This kit is now Sold Out  (The microcontroller chip is still available in the shop)