Mechanical scanning + afterglow =?

Mechanical scan displays cost a small number of LEDs - and that’s where their pluses end. They require precise program keeping of very small time intervals, as well as supplying power to the movable part through slip rings, a rotating transformer, etc.

Probably, many had the idea to use a disc, a drum or a belt with a light storage device in such a display. Information can be recorded on any of these carriers by slowly moving it past the fixed LED line, and erasing will be automatic due to the extinction of the afterglow of the phosphor. The program that controls the LEDs, while it can be quite sloupochnoy. The price of this is the loss of the ability to display animation, but horizontal or vertical scrolling becomes hardware, it is not even necessary to program it.
')
The Dutchman Jan Derogee decided to first check how spectacular such a display would turn out on the simplest Morse simulator . There is only one LED here.



After a successful “trial of the pen,” the same author swung at once to the complex display design , where the horizontal LED ruler “prints” the entire line on the horizontal drum. The problem of lack of outputs in ESP8266 is solved trivially - with the help of shift registers.



One device is too simple, the other is too complicated, is there something in the middle? Of course. The author of the site Instructables under the nickname maken_it_so designed a watch with a display on the same principle , where the disk serves as a carrier. They are made on the Arduino, and there are only 10 LEDs (the “seal” is not longitudinal, as in the previous case, but transverse), so shift registers are not required.