I’ve wanted to do this because there’s a zillion cool clocks out there that use a similar movement. I’d also wanted to make it battery powered which means doing NTP update only once per day (or less). Doubt that is realistic, tho.

Maybe embed Hall sensors and detect when the hands are in a certain position and when all three line up wake the ESP32, do an NTP update, tick it forward to where it should be, then go to sleep. Probably still use too much power, especially the Halls.

How does this keep track with DST?

Looking at the code [1], it looks like if the actual time is 1 hour ahead of the displayed time, then we get 10 pulses per second to leap forward. Otherwise, the clock stops running for an hour to fall back.

https://github.com/jim11662418/ESP8266_WiFi_Analog_Clock/blo...

Sorry if this is a dumb question, but do you guys not have radio controlled clocks outside of Europe? If I got it right, the only purpose of this project is to always display the correct time. Radio controlled clocks do exactly that. They are cheaper than the one ESP board, and run years on a single AA battery. No WiFi, tinkering, setup, or cables necessary

On this topic. Do WiFi signals contain time (unencrypted)? If so why does my oven not pull time from the air and needs adjustment every 2 months? If not, why are APs not defacto time beacons for all sorts of non-smart appliances (and clocks)?

This is great. I spent years looking for an affordable battery-powered WiFi clock that syncs via NTP since where I am, the WWVB clocks never pick up the radio signal.

I never considered making my own. Anyway, about two years ago this option popped up on Amazon. I've been happy with it:

https://www.amazon.com/OCEST-Wall-Clock-12Inch-Auto/dp/B0DJS...

I'm guessing internally it's not much different than the DIY clock in this submission.

I'm currently making something similar but using a BKA30D-R5 (a dual stepper motor used in car dashboards) and a hall sensor to zero the hands.

Pretty awesome. The only thing I would change is to put a USB battery between the usb wall power and the D1 mini. That way for power outages of < a couple of days or so you're clock will be fine.

What's the best way to periodically get time and date if your customers are big businesses with hostile IT departments?

I’m curious how long it takes for the hands to drift to the point where the time difference is perceivable. Luckily the 30 millisecond pulse time is configurable.

It'd be interesting to see the logs or data on how the physical movement falls out of sync. It probably even correlates with temperature and humidity.