Look Ma, No Hands!

by Denis Meyer | 16 May, 2019

This circular wall clock comes as a partially assembled kit. It is presented in the form of a simple ring of about 25 cm (10 inches) diameter, to hang on the wall. In fact, all you see is this sober black crown a few centimetres in size, which acts as the dial. No display, no hands, no second hand, no pendulum, nothing like that. And yet, like all good timepieces, this one does have hands, a second hand, and even a pendulum.

This partially assembled kit from Velleman is offered by Elektor in the store: it’s just a ring of around 25 cm (10 inches) in diameter, which hangs on the wall. You see nothing but this sober black crown, several centimetres in size, which serves as a clock face. No display, no hands, no second hand no pendulum, nothing. But yet this timepiece tells the time, with hands, second hand, and even a pendulum… all virtual!

A compilation of clocks, would that be interesting?

At Elektor, we have often thought of publishing a compilation of all our innumerable electronic clock circuits. But I think such a publication has never seen the light of day. And if I am wrong, it would be because its short-lived success can’t have made much impression. I do remember very well some epic discussions during which the proposed compilation project was invariably shot down. “Our readers love clock circuits, of course. But to go from there to a compilation: NO!”

However few subjects have generated as many rejections as electronic clocks. Every Elektor reader has been has been struck at least once by a memorable electronic clock circuit. So I’m taking this opportunity to ask you, our readers: “Would a compilation of clock circuits published by Elektor be of interest to you?”

Please respond in the comments below.

A black crown surrounded by coloured light

What time is it? About 7:25 and 12 seconds…

Here, everything is in a ring of LEDs emitting light on either side of the crown behind which they are hidden. The display of the time here is thus similar to an ordinary round clock face where the position of the hands is represented by a halo of coloured light. A simple, original and spectacular idea. It has the practical advantage of having no moving parts or adjustments… but an ESP32 and wireless communications.

By lighting the 60 (of course!) RGB LEDs, and forming luminous patterns, we quickly learn to read them like the positions of real hands.

I can imagine this clock being a great thing to have in a waiting room, because while looking at it you don’t really sense the time going by.

Setting the colours of the hands: it’s 13:59 and 22 seconds

Arduino, WiFi, ESP32, nTP Server

The Brightdot kit (that’s the name of this clock) offers all the functions of a modern clock:

Wireless communication for automatic time synchronisation via nTP server
Setting the light animation effects from your local WiFi network
Communication with smartphone or PC (Windows, macOS & Linux)
Open source ESP-32: code (Arduino)

Kit available in the Elektor Store:

Complete BrightDot clock kit (black version)
Fully Arduino compatible & ESP32 controlled