Here is my self calibrating sundial gadget :) It's one of my newest Arduino based projects and although it's working perfectly fine I'm still trying to improve the code itself as I'm still learning.
Basically the device is equipped with two SG90 servos, GPS receiver and digital compass all connected and controlled by Arduino nano (see attached schematic).
The compass will position the sundial in North-South direction no matter what the starting position will be. Then the GPS will find the latitude and will tilt the sundial plate at the latitude angle. Other words doesn't matter where you are and where you position this sundial it will calibrate itself :D Of course you have to remember to place it in sunny spot and make sure it's reasonably leveled to get accurate time readings.
This is and equatorial sundial which has perpendicular gnomon and hour angles are evenly spread every 15 degrees and once tilted at latitude angle will give you solar time.
Physics, 3D printing, Programming, Astronomy and Sci-fi - that's me \//