#include <Keypad.h>

#include "SdFat.h"

#define SPI_SPEED SD_SCK_MHZ(4)
#define CS_PIN 10

const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};

uint8_t colPins[COLS] = { 5, 4, 3, 2 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 }; // Pins connected to R1, R2, R3, R4

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() {
  Serial.begin(9600);
  int analogValue = analogRead(A0);
}

void loop() {
  char key = keypad.getKey();

  if (key != NO_KEY) {
    Serial.println(key);
  }
}

SdFat sd;

void setup() {
  Serial.begin(115200);
  if (!sd.begin(CS_PIN, SPI_SPEED)) {
    if (sd.card()->errorCode()) {
      Serial.println("SD initialization failed.");
    } else if (sd.vol()->fatType() == 0) {
      Serial.println("Can't find a valid FAT16/FAT32 partition.");
    } else {
      Serial.println("Can't determine error type");
    }
    return;
  }

  Serial.println("Files on card:");
  Serial.println("   Size    Name");

  sd.ls(LS_R | LS_SIZE);
}

void loop() {
}