# some-01 ``` C = #include <Keypad.h>; //引用LCD_I2C.h 函式庫 #include<LiquidCrystal_I2C.h> LiquidCrystal_I2C mylcd(0x27,16,2); const byte ROWS = 4 ; const byte COLS = 4 ; char keys [ROWS][COLS] = { // 設定按鍵的「行、列」代表值 {'1','2','3','A'}, {'4','5','6','B'}, {'7','8','9','C'}, {'*','0','#','D'} }; byte rowPins[ROWS] = {9,8,7,6}; byte colPins[COLS] = {5,4,3,2}; Keypad keypad = Keypad(makeKeymap(keys),rowPins,colPins,ROWS,COLS); void setup() { Serial.begin(9600); // 設定序列埠通訊頻率 mylcd.init(); mylcd.backlight(); } void loop() { char key = keypad.getKey(); if(key != NO_KEY){ Serial.println(key); mylcd.print(key); } } ```