Arduino code for digital clock, 3D printed inspired by www.otvinta.com, https://www.thingiverse.com/thing:3266949.
I added some thin back covers to hide the cables and added two feet to give a safe stand. These files are here: https://www.thingiverse.com/thing:4313748
Author of the code: Jordi Ginjaume. Excellent code Jordi! It inspired me to do the thing with Arduino. Original Version 20190118 (his code and case can be found here: https://www.thingiverse.com/thing:3375870)
Modified for use with an ESP32 wihtout RTC, just calling NTP all 12 hours over WiFi using the following hardware:
1 ESP32 programmed with Arduino
2 PCA9685 chaining servo drivers, set solder blob on A0 on the second board for digits 3 and 4
NTP call via WiFi
28 SG90 servos
Important: keep sequence with servos plugging into PCA9685:
first digit: 0-6, leave 7 blank
second digit: 8-14, leave 15 blank
repeat on second board for third and forth digit
PIN Connections on ESP32
21 -- SLA
22 -- SLC
0 -- OA
I inserted a switch to turn off the power to the PC9685 for programming purposes.