codable remote lock for treasure chest

It is a codable four-digit lock that can be activated remotely. The default code is 1234 but can be modified by editing the program.

It uses :
-2 micro:bit cards ;
-a servo motor sg90 ;
-a 5V battery (like powerbank) to power the servo motor.
-a USB cable to power the servo motor like this one for example: https://www.amazon.fr/gp/product/B00M552AE2/ref=ppx_yo_dt_b_asin_title_o07__o00_s00?ie=UTF8&psc=1 ;
-2 springs.

The pieces are based on the Taiwantoni lock and his idea of using a B