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 ...

[Teatree] tells a sad, sad story about the lost password for his fire safe. The electronic keypad comes with a manufacturer’s code as well as a user selected combination. Somehow he managed t… ...