What is Kairos?

The ancient greek word “Kairos” represents the concept of a moment in time. Unlike “Chronos” that refers to the passage of time. Of course anyone building a clock, a timepiece or a timer is going to use the latter word in their product name. This little story tells you that Kairos is about time. It is about hardware and software that we use to indicate your moment in time - In short: clocks!

I never set out to make clocks. The premise of the project was an off-the-cuff remark about how the little LED filament strips used in cafe style light globes might be used to make seven segment displays:

These are a sample of the stocks we now have. These are “COB” or “chip-on-board” LED filaments used in café style filament lamps. They are available in a range of sizes from about 12mm up to more than 68mm in daylight, warm white (several color temperatures), red, green, blue and even purple.

We started using them as light sources in our first prototype garden lamps. They require just 3V per filament, and five in series can be lit with a 15V constant current booster very nicely - this is what that all looked like:

That was a very interesting first project - but what does it have to do with clocks?

Well - a whimsical remark was made about how the “straight” format of the filaments could be used to make a cool old-school seven segment display: the type that everyone is familiar with in their microwaves and bedside clocks.

At the same time, we had take delivery of a Volterra V-One PCB printer. This device could print conductive ink on PCB substrate, drill holes and more or less delivery a prototype PCB on the desktop. So the idea of a relatively simple seven-segment display PCB presented as a perfect test project for the machine.

… and there you have it: our printer making the first digit display board (only one side of a two sided board). This worked well enough to hook the board up to an Arduino and get some segments glowing:

That isn’t actually the prototype, its a bit further along in the story which I will continue in my next post.