# Main Content

In a previous instructable, I have presented a concept for making a “linear” binary clock from a standard WS2812 LED strip and an ATtiny microprocessor. The design of that clock was not that great… …which is why I made a new version using an LED ring.

This clock will show the hours, minutes, and seconds of the current time in a binary style on the 16 LEDs of the ring - 4 representing the hours (blue), 6 representing the minutes (pink) and 6 representing the seconds (green). You will get the correct time, if you just add the single 2x values of each LED. As an example, it is 11:36:49 a.m. in the picture above. Hence, the clock lights the blue LEDs “0”, “1”, and “3” for the hours (= 20 + 21 + 23 = 1 + 2 + 8 = 11). It will also light the pink LEDs “2” and “5” for the minutes (= 22 + 25 = 4 + 32 = 36), and the green LEDs “0”, “4”, and “5” (= 20 + 24 + 25 = 1 + 16 + 32 = 49).

Simply put, a binary clock is not making life easier, but it trains the brains…

For making this clock, you will need:

- 1x LED-Ring with 16 WS2812 LEDs (inner diameter: 54 mm; outer diameter: 68 mm)
- 1x ATtiny85 (20U - DIP-8 version with 5V)
- 1x DS1302 (or DS1307) RTC chip (DIP-8 version)
- 1x 32.768 kHz Crystal Oscillator with 6pF Load Capacitance
- 1x PCB Prototyping Board (Perfboard): 14 x 20 Holes // 40 x 60 mm
- 2x 8 Pin DIP Socket
- 1x Battery Clip (diameter 20 mm)
- 1x CR2032 battery
- 1x 2-Pin Terminal block (optional)
- 1x 47 µF Capacitor (optional)
- 1x Barrel Jack Socket 5.5 mm/2.1 mm (w/ M7 Nut)
- 1x 5V DC Power supply or USB to Barrel Jack Cable
- 1x Breadboard (optional)
- Some 0.14…0.25 mm² Cable
- 1x USP Programmer or Arduino Uno + Some Jumper Cables
- 1x Sheet of Tracing Paper (i.e. “Transparent Paper” for copying drawings)
- 4x M2 Screw and 4x M2 Nut
- 3x M3x25 Screw and 3x M3 Nut
- 1x 3D Printer and some filament, or a Printing Service, or some Self-made Case

Please note: There are different sizes of the LED rings with 16 LEDs out there. My housing design uses the version with an outside diameter of 68 mm (and an inner diameter of 54 mm). The rings with an outer diameter of 70 mm should fit, too. There are, however, much smaller sizes like the original Adafruit or NeoPixel versions that have an outer diameter of 44.5 mm. Those versions will not fit here!
Please note: The DS1302 need a 32.768 kHz crystal oscillator that expects a load capacitance of 6 pF (which is included inside the DS1302). Most crystals with 32.768 have a load capacitance of 12.5 pF which might cause a drift of a few seconds a day. You may use these crystals if your ok with the drift, or you might add extra capacitors as explained here. In the end, the DS1302 and a (cheap) crystal will show a drift of a few seconds a day anyway. If you want a more precise RTC, maybe take a look at the DS3231.”

Link to article