Getting a 4-digit number from a keypad

Projects Programming
14

Try this one. Study it. Understand it. Then write something like it for your own use.

#include <Keypad.h>

const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns

//define the symbols
char stdKeys[ROWS][COLS] = {
  { '1' , '2' , '3' , 'A' },
  { '4' , '5' , '6' , 'B' },
  { '7', ' 8', ' 9', ' C' },
  { '#' , '0' , '*' , 'D'}
};
byte colPins[ROWS] = {2, 3, 4, 5}; //connect to the row pinouts of the keypad
byte rowPins[COLS] = {6, 7, 8, 9}; //connect to the column pinouts of the keypad
int myInt = 0;
byte digitCount = 0;

//initialize an instance of class NewKeypad
Keypad customKeypad = Keypad( makeKeymap(stdKeys), rowPins, colPins, ROWS, COLS); 

void setup(){
  Serial.begin(115200);
  Serial.println("Enter a 4 digit number");
}

void loop(){
  char Key = customKeypad.getKey();

  if (Key >= '0' && Key <= '9'){
    Serial.println(Key);
      myInt = (myInt * 10) + Key -'0';
      digitCount++;
    if (digitCount == 4) {
      Serial.print("You entered: ");
      Serial.println(myInt);
      digitCount = 0;
      myInt = 0;
    }
  }
}