connect to the row R1-R4 pinouts of the keypad byte colPins[COLS] = {2, 3, 4}; //connect to the column C1-C3 pinouts of the keypad Next is a project example, where the Arduino is instructed ... the ...

He’s constructed an Arduino keypad door lock — without using any proper fastening hardware! The entire build is made out of scrap parts he had lying around: some DVD’s, a bit of wood ...