This is another Electronics DIY project of mine
It is a security system that i built for my room. The access is controlled by a PIN or an RFID tag.
An ATMega328P controls the Drop Bolt solenoid that locks the door. MFRC 522 reader and a 4×4 keypad are used here. A backup power supply is needed inside the room to make it failsecure although i wouldnt recommend it without testing your system’s reliability. To exit the room a button is to be pressed that would momentarily disable the lock. RFID tags can be added or removed without needing to reprogram. The system can be reset using another button provided inside.
RFID libraries are readily available, but programming knowledge is required.The system can be modified to fit a car so that ignition is controlled by the keypad like Jason Statham’s car.
Drop bolt solenoid