Introduction: CountClock in Tidal Mode

About: Openproducts' focus is on design of new products and on innovative approaches towards improving existing products. An example: the CountClock, a concept facilitating children to learn telling the time. Purpose…

To avoid confusion: the CountClock in Tidal Mode does not indicate ocean tide, but it indicates time. The tidal aspect in this Instructable refers to the visual presentation of time, which appears similar to the rising tide.

CountClock Concept

The CountClock introduces a different way of looking at the analog clock. Basic principle is that time can be read out by counting the lights, and that's why the device is called CountClock. How it works? The inner circle of lights represents the hours: one light means that the hour is one, two lights indicate that the hour is two. And so forth. The outer circle represents the minutes: one light means that the minute is one, two lights show that the minute is two. And so on.

Design for Kids

The CountClock is a clock specially designed for children: it helps them to better understand how to tell the time from an analogue clock (note that this does not apply to the Tidal Mode, but is does apply to the special Learning Modes, see Step 1 below for more info). The CountClock project was launched on Instructables in January 2018 in the Design for Kids Contest. Feedback from the audience on this open source project often refers to the need for facilitating children’s clock learning process: what use is a clock that is useful only during the clock learning process? The CountClock in Tidal Mode shows that the CountClock is not only a learning clock, it is also a decorative and functional clock for anyone who’d like to know what time it is.

CountClock in Tidal Mode

Now about the CountClock in Tidal Mode. All over the world, people have learned how to interpret the analog clock: 12 is at the top, 6 at the bottom, 3 to the right and 9 to the left. Even without the numerals on the scale everybody knows how to interpret the position of the hour hand and the minute hand. The CountClock in Tidal Mode uses a different convention, which is easily possible because the sole criterion for reading out time is to count the hour lights and the minute lights. The convention used is this: the hours and the minutes start displaying from the bottom of the clockface. As time is running, the minute lights accumulate as water in a bowl. Once the bowl is full (all minutes in an hour have passed) the next hour is highlighted and the minute goes to zero again. Just like in conventional clocks. Then the cycle starts over again: the minutes accumulate and once all minutes in an hour have passed an additional hour is highlighted, bringing the minute back to zero again. This continues until 12:59, and then all hours - except the one at the bottom - and all minutes are reset to indicate 1:00 again, as indicated in the GIF animation above.

The CountClock presented here uses an Arduino controller with libraries to drive the multicolored LEDs. The build presented here uses minimal components, not even a timer module. The time is kept by the Arduino controller itself and adjusted permanently, which requires a calibration step by the programmer. Adding a timer module to your CountClock is recommended though. The Tidal Mode will be further developed to also contain changing colors and possibly also a falling tide, next to the rising tide.

This instructable presents all manufacturing design files and the Arduino program code to make your own Tidal CountClock. In several steps it is referred to earlier published Instructables, that in detail describe the building steps. First however, the concept behind the CountClock is illustrated in Step 1 below: it is an important feature for appreciating the open source CountClock project.

Step 1: CountClock Concept

The CountClock was designed to assist young children in learning to tell the time: the confusing concepts of an analogue clock (the double scales and double hands, the numerals (or their absence), the half hours and quarters) are all decomposed and offered as separate learning steps, tuned to young children. Multi-colored lights indicate time on separate hour and minute scales. For the youngest children for example this results in only presenting the full hours. Just by counting the lights they can read off the hour: knowing the numerals is not needed. In every learning step additional concepts of analogue time can be added, like half hours or quarters. For the older children all minutes including the seconds can be highlighted; in this highest learning level the looks of the CountClock closely approximate a conventional analogue clock. More info on the CountClock concept can be found in the original Instructable: (January 2018).

Step 2: CountClock Tidal Mode

Put yourself in the position of a child that learning to tell the time: doesn’t it sound logical to start counting at the bottom of the clockface? Experienced timetellers may at first be confused by the Tidal Mode. If in doubt, just refer to the basic principle of the CountClock and count the hour lights (on the inner circle) and then the minute lights (on the outer circle). If exact time is not so important the Tidal Mode is also well-suited for estimating time: especially the half hour is quite easy to discern. Also a quarter is a well-know entity to the eye. In order to give a balanced picture, the minute lights show up in a two-minute interval, indicating only the odd minutes: 1, 3, 5, …, 29, 31, … 59. And finally also minute 60 (usually not present in analog clocks, nor in digital ones) is highlighted for a second to visually close the circle before it is reset to zero again (see the animation at the start of this Instructable).

Step 3: Wooden CountClock Casing

The CountClock housing is a sandwich construction of multiple wooden panels. The middle panel has a large cavity that allows to place the electronic parts. The front panel has 12 holes for the hours and 60 holes for the minutes. These holes each have rounded light pipes that guide the light from the LED strips to the visible front, thus allowing to read off the CountClock from an angle. The best looks for the wooden CountClock housing is when it is made using CNC milling (because of its high accuracy and fine cuts). The CNC milling design files are available in multiple flavours: the source is in human-readable scalable vector graphics (SVG), for the router the DXF file is available. The design files are available in a separate Instructable, see Steps 6 and 7 in

Step 4: Electronic Parts

This version of the CountClock has only an Arduino controller (Adafruit Trinket Pro) and two LED rings (Adafruit Neopixel 24 (of which only 12 LEDs are used for the hours) and Adafruit Neopixel 60 (in four quarters of 15 LEDs) for the minutes). The components are listed below, including links to the manufacturer's webshop:

Other electronic parts you may easily purchase in your local electronics shop: a condensor (1 micro-Farad), a resistor (1 kOhm), conventional bulb LEDs to be used as light pipes (12 larger, say 8 mm and 60 smaller ones, say 5 mm in diameter). And some wiring and soldering needs. You might also consider integrating a light sensor in order to adjust the LED brightness to the ambient light.

Adding a timer module is a good idea for improving the CountClock, but that is not done in this Instructable. The optional element is a Real Time Clock module (for example the DS1307 at Without the timer module you'll be continuously monitoring whether your CountClock keeps good time (depending on the success of the calibration step).

For connecting the electronic parts it is referred to the manuals by the manufacturer’s NeoPixel Überguide.

Step 5: Protective Template

The protective template is an important component in the CountClock design. It has constructive and safety purposes, but also esthetic functionality: it guides the light in such way that only the targeted light is on, and not he neighboring lights. The protective template is a plastic slab, best made on a laser cutter. The source file is available is in human-readable scalable vector graphics (SVG) and for the lasercutter a DXF file is available. The design files for the protective template are available in a separate Instructable, see

Step 6: Arduino Code

The code for programming the CountClock in Tidal Mode is presented in this step. Arduino libraries that are used: TimeLib by Michael Margolis and Adafruit’s Neopixel library. The programming is straightforward and the current version does not vary the colors:

  • For the hours the LED ring has 24 LEDs, while only 12 lights are required. This means that one LED is skipped between the hours. Reason for opting for the ring with 24 LEDs is the larger size in diameter.
  • Neopixel LEDs are very bright, which especially at night is inconvenient. Therefore, the LEDS are dimmed during the evening and even more during the night time. This is done with the variable ‘Dimfactor’ which varies between 10 and 30.
  • In this design no timer module is used, which means that the timer capability of the Arduino board is used. Its clock is not very accurate (which is defendable for many purposed but not handy in a clock) so a calibration is required. This is done in the lower part of the main loop, but adjusting the time several times every minute with a fixed amount of seconds forward (drawback is that the seconds hop irregularly, a band-aid solution is to not display the seconds). In the current code, adjustments are made twelve times every minute, by 2 seconds forward. Further tuning may be necessary, for example every hour, and the fine tuning will be done once a day. It is recommended however to use a timer module, see Step 4.

Download the current version (version 1.0 from July 2018) of the Arduino code for the CountClock in Tidal Mode below.

Step 7: Rainbow Colors

Besides the Tidal Mode, there is another CountClock variant that targets people that know already how to tell the time: it is the CountClock in Rainbow Colors. It has a separate Instructable:

Step 8: Small CountClock

The CountClock presented in this Instructable shows both the hours and the minutes. Besides this large version, a small CountClock is also available, which only displays the hour. The reason for designing the small CountClock is that it for children learning to tell the time (the original target audience for the CountClock, see Step 1 above), getting to know the hour is the first step towards understanding the analog clock. In that stage the presence of minutes is more disturbing than helpful, and besides the social world of small children does not require time awareness sharp to the minute. More info on the small CountClock can be found here:

Step 9: CountClock Prototypes

The CountClock presented in this Instructable was first prototyped in single-color LEDs and controlled using shift registers, both in small and large variants. These prototypes were both presented in separate Instructables (both published in January 2018):

The single-color LEDs give a nice light but connecting them via shift registers is quite laborious, especially when also minutes are to be displayed. For future versions of the CountClock perhaps multicolored epoxy bulb LEDs will be used, but the challenge is how to control them. Suggestions are welcome!

Step 10: Share the CountClock Concept

The open source CountClock was designed as a clock that facilitates children in learning how to tell the time.

As this Instructable shows the CountClock liekewise is perfectly suited for anyone who likes non-standard clocks. If you like the concept then please feel free to share the concept via social media (via Twitter and FB You might also point people to the Instructables gallery by Openproducts or point them the CountClock website

The CountClock and its open source design files are freely available via Instructables, but the CountClock may also be bought as a complete and working product, plus a DIY kit containing only the casing and the protective template via the Openproducts webshop at (no sales though in August 2018, webshop will be closed).

Thanks for reading!

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