This Binary Clock’s Circular Arrangement and Position Numbers Are Easier to Read

Binary clocks and watches are a cool way to show off your geek street cred. If you can comprehend binary quickly enough for it to be practical way to read a clock, then you must spend a lot of time doing low-level computing. Most binary clocks use a series of LEDs arranged in a line or grid to represent binary digits. You only need a total of 16 LEDs for this (6 for seconds, 6 for minutes, and 4 for hours 1-12). But it can be a little difficult to intuitively understand the digit positions, which is what JohnThinger’s Circular Binary Clock improves upon.

In binary, each subsequent digit multiplies the previous digits. Thanks to the power of exponents, we can represent huge numbers in relatively few binary digits. The binary sequence for the decimal number 63 (starting at 0) is, for example, “111111” and you can test this for yourself by multiplying 2 by itself 6 times. Another way to think about it is that each position starting at 0 (N) represents the number 2 to the power N. So you can determine that “001001” equals the decimal number 9, because 2 to the 3rd power equals 8 and then add the final 1. The Circular Binary Clock makes this much easier to calculate by labeling each position.

As you can see, the clock has 16 numbers arranged around its circumference. Those correspond to the 16 binary digits necessary to represent 60 seconds, 60 minutes, and 12 hours. If a number is lit, then it is a 1 in binary. The numbers represent the position of each binary digit: 0-5 for seconds, 0-5 for minutes, and 0-3 for hours. The numbers are also lit in blocks to help you understand which digits represent seconds, which represent minutes, and which represent hours. To find the time, you just calculate 2 to the N power represented by each digit. Add up the seconds calculations, the minutes calculations, and the hours calculations and you have your time.

A Microchip ATtiny85 controls the LEDs behind each digit. It tracks the time using a DS1302 real-time clock with a 32.768kHz crystal oscillator controlling the processor clock. Power for the RTC comes from a CR2032 coin cell battery, while the primary power comes from a 5V DC power supply. The enclosure is 3D-printable and looks a bit like a radiator cap — though that seems to be unintentional.

This obviously isn’t a practical way to tell the time. It is much easier to use a standard analog or digital clock, as few of us read binary quickly. But that’s kind of the point; this clock will be indecipherable to most people, which will make it all the more impressive when you can read it.