#include <Keypad.h>


// 定义Keypad的行和列数量
const byte ROWS = 4; // 四行
const byte COLS = 4; // 四列
// 定义Keypad的按键布局
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {13, 12, 14, 27}; // 将这些引脚连接到Keypad的行引脚
byte colPins[COLS] = {26, 25, 33, 32}; // 将这些引脚连接到Keypad的列引脚
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  Serial.println(getChar());

}

String getKeypadString() {
  String inputString = "";
  char key;
  while (true) {
    key = keypad.getKey();
    if (key != NO_KEY) {
      if (key == '#') {  // '#' 作为输入结束的标志
        break;
      } else {
        inputString += key;
      }
    }
  }
  return inputString;
}

char getChar() {
  char key;
  while (true) {
    key = keypad.getKey();
    if (key != NO_KEY) {
      return key;
    }
  }
}