README.md

I'm rarely impressed by alternative clock displays firstly because the traditional analog design is so damn good. You can tell the time at a glance just from the angle between the two hands: how can you improve on that? But then I found this bizarre watch display on the internet (press download to view the video).

Hard to realise on a mechanical watch ;) but interesting. And it got me thinking. This repo has analog and digital clocks on the e-paper display. In theory e-paper should be ideal for clocks with exceptionally low power consumption: zero if you switch them off! Results were poor as there are two choices. Either you refresh the display normally, in which case every (say) 1 minute the screen goes through a five second rigmarole to update. Or you use fast updates, in which case you get ghosting.

E-paper displays in fast mode are additive. Ghosting only occurs when you turn a black pixel white. I therefore devised this adaptation of the video which only turns pixels white with a full refresh once per hour.

As in the video the display inside the circle is a window onto a dial too large to fit the screen. The dial is the minutes display, with a range of +-30 minutes. The hour hand (chevron) moves to the next hour when the minutes pass 30, with the minutes before or after the hour shown by the black band on the scale.

The above image shows 20 to 7 PM, that below shows nearly quarter past 2 PM. Like a conventional analog clock it encourages reading the display in the way in which we normally describe time.

Implemented on a Pyboard 1.x with Pervasive Displays EPD.

This demo will need minor adaptation to run. The micropower import is only required for my hardware, to turn on power to the display.

Main README