How it works:
- According to the time provided by RTC, Arduino moves the 28BYJ-48 stepping motor.
- The right drum moves one step per minute, and the left drum moves one step per hour. Attach 60 plates to each drum.
- With a photo reflector in the drum, Arduino knows the absolute angle.
For the four digit split flap display clock I made previously, improved the following things:
- Reduced the number of motors from 4 to 2.
- Remove of gear by coaxial arrangement of drum and motor.
- Wiring hidden in the frame.
- Reduces the influence of ambient light by changing the position of the infrared sensor.
It takes a long time to paste the number seal. It took me a day. If you have a printer with a dual nozzle and you can make 3D data of a plate with numbers, you can easily print it.
I uploaded Arduino sourse code and schematic.