连线图：
/* @file HelloKeypad.pde
|| @version 1.0
|| @author Alexander Brevig
|| @contact [email protected]
||
|| @description
|| | Demonstrates the simplest use of the matrix Keypad library.
|| #
*/
#include <Keypad.h>
const byte ROWS = 4; //four rows
const byte COLS = 4; //three columns
char keys[ROWS][COLS] = {
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'*','0','#','D'}
};
byte rowPins[ROWS] = {5, 4, 3, 2}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {9,8, 7, 6}; //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){
Serial.println(key);
}
}