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 to do ...

Pins are mapped to four rows and four columns on the keypad. A user reads the keypad by bringing each row up to logic: HIGH, and reading the corresponding column values, (HIGH or LOW). Keypad ...

the Arduino brings one keypad input line high and checks the voltage of the four output lines in order. The diodes on the PC board prevent feedback across the rows and columns. The RGB LEDs are ...