Learn how to make a door lock system using password with keypad and electromagnetic lock. When the door is unlocked by a correct password, It keeps the door unlocked for 20 seconds, and then automatically lock the door again. The Arduino Nano ESP32 code supports multiple passwords. The detail instruction, code, wiring diagram, video tutorial, line-by-line code explanation are provided to help you quickly get started with ESP32. Find this and other Arduino Nano ESP32 tutorials on Newbiely.com.