Reinventing obsolete devices seems quite popular now, enter the “Bulbdial” concept –
I think we can all agree that sundials pretty much suck. They only have an hour hand, they donâ€™t work at night or indoors, their accuracy changes with the seasons, and if you happen to live in the Southern hemisphere they run backwards. And yet, we all would love to be able to tell the time by looking at shadows, right?
The Bulbdial Clock has no hands â€” just one pole in the center of the clock, and three light sources of varying heights which revolve around the pole casting shadows. In the model illustrated above, the light sources are each attached to a ring which rotates around the pole. The innermost ring rotates once per minute, casting a â€œsecond handâ€ shadow. The middle ring rotates once per hour, and casts the â€œminute handâ€ shadow. And the outer ring rotates once every 12 hours, casting the â€œlittle handâ€ shadow.
It appears this design would necessitate indoor usage. Seems quite do-able with microccontroller + LEDs. – Bulbdial on Ironic Sans
DIY Sundial for your garden