Keypad pin 4 to Arduino digital 8 //R4; Keypad pin 5 to Arduino digital 4 //C3; Keypad pin 6 to Arduino digital 7 //R3; Keypad pin 7 to Arduino digital 6 //R2; Since keypads are available from many ...

The system auto-locks after 5 seconds, and just in case, [Andrea] has hard-coded in a few safety codes into the firmware to allow him to forcefully open the door — you know, if it malfunctions ...