The rows of the keypad are connected to arduino pins 2, 3, 4, and 5, and the columns to pins 6, 7, 8, 9. See below for a full connection table.
Click "Run code" to see the demo program in action.
Pin connection list:
| Keypad pin | Arduino Pin |
|---|---|
| R0 | 2 |
| R1 | 3 |
| R2 | 4 |
| R3 | 5 |
| C0 | 6 |
| C1 | 7 |
| C2 | 8 |
| C3 | 9 |
#include <Keypad.h>
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
{'1', '2', '3', 'A'},
{'4', '5', '6', 'B'},
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {2, 3, 4, 5}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {6, 7, 8, 9}; // Connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
void setup() {
Serial.begin(9600);
}
void loop() {
char key = keypad.getKey();
if (key != NO_KEY) {
Serial.println(key);
}
}