automatic calibration

[HR-zju]

Hi, I was wondering how you got to know what time the clock is showing now, when you use ntp to calibrate the time.

[HR-zju]

By the way, can you provide a picture of the hardware connection

[nikzin96]

Hello,

you can find the project with the hardware connections here: https://www.instructables.com/Hollow-Clock-4/
just connect the pins I used in the sketch, but you can also just change the pins.

About your question: when you power up the clock you need to set it to 12 o´Clock, this is what i assumes. From there it sets itself. After that it only checks every 10 seconds if the time on the NTP server has changed and then takes the amount of steps specified. In my comment on the instructables project I said, that so far I have no feedback for the clock to know if it actually is correct. That could be a future improvement to include a hall sensor or similar to give it some feedback and correct any mismatches. The one I have running since around christmas is still perfectly correct.

To get the correct steps I made a test sketch to let it rotate some amounts and see if it´s still correct. Then I calculated the actual steps per rotatoion for my clock. This can be different for every clock because of differences in the mechanical parts.

I hope this helps you. If you have any further questions just let me know.