“There are 10 kinds of people in this world….” and you know the rest.
Can you tell the time?
Watch the intentionally bad focused video below to see in which category you fit…
The mysterious device you can see is my binary clock. If you couldn’t tell the time that easily or at all it is because my clock is a few times more complicated than normal binary clocks.
Simplest binary clocks represent each digit of a clock with 2 3 or 4 LEDs in a binary form and clearly mark what each column means and the value of each bit as you may see here.
I wanted to make one that is more special and as hard to read as possible. So first step to making the clock less understandable by most people is to remove all markings of what the LEDs mean. This was easy.
Seconds, minutes and hours are all numbers, there’s no need to split them into digits…. each number can be represented on 6 (m, s) or 5 bits (h).
I choose one color for each or the three numbers to make things more colorful: red for hours, green for minutes and blue for seconds. And then I used something familiar in electronics and not only: multiplexing. I simply overlapped all the three sets of 6 bits. The result: more colors and fewer LEDs. Only 6 of them… RGB LEDs. Now I can explain the name: Color Multiplex Binary Clock (CoMBi Clock).
If a LED is red, it means that it is a 1 for the number representing hours. If it is yellow it means it is 1 for hours and 1 for minutes. If it is white it is 1 for hours, minutes and seconds and so on.
The seventh white LED on the left is there to help the readout. I’ve added it for easier readout in the dark.
There’s no case, no instructions, no labels, just the bare PCB to make is as geek friendly as possible.
And now for the technical details: the brain is an ATMEGA8535. It was chosen mainly because it has 4 PWM channels, three for each color and one for the white LED. This allows it to adjust the brightness of the LEDs according to the ambient light level measured by a photoresistor. Without this feature the LEDs will simply be too bright in the dark.
The heart is a DS3232 real time clock backed up by a CR2025 battery for permanent correct time even when the power goes down. Two buttons allow for time adjusting.
Initially I planned to include a thermometer too, hence the extra space for three buttons and a 1 wire temperature sensor on the PCB. But I was missing the sensor at the time of the build and as I think that a binary thermometer is just not that cool I didn’t add it…maybe later.
I have used transparent LEDs because they were brighter and allow an easy readout in daylight. The diffused LEDs I was able to find were simply too dim. Because the colors don’t mix so well in transparent LEDs I had to add a diffuser.
If I will find some bright enough diffused LEDs with good color blending I will make a circular version like a normal clock and watch, probably without seconds. Oh, and add the temperature sensor on this one.
For more pictures see the gallery below: