Half-Dial Clock or Dialog With Know-it-all

Know-it-all. What do you want to show this time? I see some strange clock dials.

Jumbleview. Above you can see snapshot of web page to display local time on your computer. Here is link to this page: https://tinyurl.com/half-dial-local-time .

Kia. This link is unclickable. Why?

Jv. For some reason Instructbles editor doesn't allow me to set clickable link. You can still select link with the mouse, copy it, and paste it in a new browser tab/window.

Kia. Is it safe?

Jv. Absolutely. This page is hosted by private cloud provider and I am only one who has a write access.

Kia. OK, I did opened it and saw how it works. I believe some explanations needed.

Jv. Sure. There are several clocks: some are traditional and some are very specific. On the left column there are two traditional clocks: analog on the top and digital on the bottom. Middle and right columns contain four clock which shows time in some different ways.

Kia. They "shows time in some different ways"?. Are you telling us that you invented new clock interfaces?

Jv. Word "invention" probably is too bold here. Still I believe there is some novelty in it.

Kia. Alas, real time moves too slow. It is a long wait to see how various times are shown by your clocks.

Jv. In that case let us move to the next step.

Jv. I have build one more web page which simulate clocks. And here is the link:
https://tinyurl.com/half-dial-simulator

It has two controls:

• Button to start/stop simulation
• Slider to speed up or slow down clock simulation pace.

Kia. OK, I see. It is better. Still it would be nice to have some explanation.

Jv. Next steps provide some. They contain sketches with traditional analog clocks positioned next to the new designs.

Jv. Here is the first sketch. Left column shows regular analog clocks. Right column shows what I named arch clocks. Clocks on the same row shows the same time. This example show us these times, namely:

• Top row: ten minutes past two.
• Bottom row: ten minutes past ten.

Kia. I think I got it. For regular clock hands are radiuses of circles: smaller one is for hours; bigger one is for minutes. Normally you tell time looking at the angle between dial vertical axis (line which goes through dial center and mark 12) and clock hand (radius). But there is another way to show the angle: arch. This is what we see on the right dials: arch on smaller circle represents hours, arch on bigger circle represents minutes.

Jv. Exactly. Arches start at 12 mark and ends at mark representing current time.

Kia. Telling the time out of this clock is almost the same as telling it out of a regular clock. In addition one may say that two arches never obstruct each other (which happens with hands of a regular clock). Such a clock makes a sense for computers/phone applications or smart watches but it would be hard to recommend for DIY device. Not easy to implement, unless you have some graphical display.

Kia. This sketch is confusing. You just cut of left part of the dial with arches !? Why?

Jv. There is the reason for that. Let us look first at the top row. For regular clock both hands positioned on the right part of the dial.

Kia. I see it. And arches on the right dial are the same as in previous step.

Jv. Good, now look at the bottom row. Minutes hand of the regular clock is positioned on the right side as well. So minutes arch are again the same as in previous step.

Kia. OK, I think I got it. Hours hand of the regular clock is positioned in the left side of dial. But there is no left side of the dial for arch clock. So you changed direction of the hours arch. Now it starts not at 12 mark but at 6 mark. That way you can show hours from 6 till 11.

Jv. Exactly. If there are some confusion you can play with simulator to see how arches change with time. When minutes hand of regular clock positioned on the left side of the dial, arch of the new clock starts at 30 minutes mark.

Kia. You know, maybe I can get used to it, but why? This design saves same space but for computer application or even phone it is no that important. And regarding the DIY devices you have the the same problem is in previous step: it is hard to draw continues arch if yo do not have some graphical display.

Jv. Still you can use it for some smart watches. Saving some space make a sense there. If you do not accept this design at all it does no make a sense to read further through this instructable.

Kia. We got so far I would like to stay with you till the end.

Jv. Here we see arch half-dial clock but with important change: arches are not continues but discrete. Hours arch made out of seven big dots and minutes arch made out of seven big dots and 4x6=24 small dots.

Kia. I see, these dots looks very like LEDs. So this design can be used to build LED digital clocks. You need only 38 LEDs to implement such clocks. It is not hard to control two LEDs with the single microcontroller pin. One can build this clock with Atmega328 microchip.

Jv. Right. Atmega328 has 23 IO pins: enough to build such a clock. But let us move a little further.

Jv. Here I eliminated small LEDs from minutes scale. Minutes scale has only LEDs showing time with five minutes precision. But there are four small LEDs to the left. They provides one minute precision.

Kia. OK. I just need to add number of lighted small LEDs to time shown by minutes scale with big LEDs. Please, provide one more example when all arches start from the bottom?

Jv. Here is the last example. Can you tell time looking only on the right image.

Kia. I believe I can: it is ten hours forty two minutes. Or telling it in proper English it is eighteen minutes to eleven.

Jv. Congratulation. You got it right. I feel it is cool minimalistic LEDs constellation which shows time with one minute precision. At first glance this design is confusing but after some practice it is as easy to read as any wall clock.

Kia. Will you build this project with real LEDs.

Jv. I will, as soon as I will have a free time.

Kia. Sure. Tell me how busy you are. Busyness is the lame excuse for lazy people, who can't manage time. Tell us at least how you build web pages for this project?

Jv. Web pages for this project written in JavaScript with usage of excellent p5js GUI library. At the beginning I learned how to use this library from the book shown here. Later I switched to the home site of this library https://p5js.org/

All code of this project is available at GitHub: https://github.com/jumbleview/halfdial

Kia. OK, see you next time. Hope you will present real clock, not simulation.