beli token v2

// Library NFC
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_PN532.h>

#define PN532_SCK  (PA5)
#define PN532_MOSI (PA7)
#define PN532_SS   (PA4)
#define PN532_MISO (PA6)
#define PN532_IRQ   (2)
#define PN532_RESET (3)


// Library OLED
#include "Arduino.h"
#include "Wire.h"
#include "Adafruit_GFX.h"
#include "Adafruit_SSD1306.h"

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

Adafruit_PN532 nfc(PN532_SCK, PN532_MISO, PN532_MOSI, PN532_SS);

#if defined(ARDUINO_ARCH_SAMD)
#define Serial SerialUSB
#endif

void setup(void)
{
#ifndef ESP8266
#endif
  Serial.begin(115200);
  Serial.println("Hello Arif!");

  nfc.begin();

  uint32_t versiondata = nfc.getFirmwareVersion();
  if (! versiondata) {
    Serial.print("Didn't find PN53x board");
    while (1); // halt
  }

  nfc.SAMConfig();

  Serial.println("Tempelkan kartu pelanggan");

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
}

String str1, str3;
String str2 = "0x49 0xB3 0x9E 0x2B";
void loop(void)
{
  uint8_t success;
  uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 };  // Buffer to store the returned UID
  uint8_t uidLength;                          // Length of the UID (4 or 7 bytes depending on ISO14443A card type)

  success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength);

  if (success)
  {
    String str22 = hexify(uid, uidLength);
    results(str22);
  }
}

String hexify(uint8_t u[], byte len)
{
  String out = "";
  for (byte i = 0; i < len; i++)
  {
    String a = String(u[i], HEX);
    a.toUpperCase();
    if (a.length() == 1) a = "0" + a;
    out += "0x" + a + " ";
  }
  out.trim();
  return out;
}

void results(String str)
{
  if (str == str2)
  {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);

    display.setCursor(0, 0);
    display.print("Pelanggan dikenali");

    display.setCursor(0, 8);
    display.print("sebagai :");

    display.setCursor(0, 16);
    display.print(" > 1303167045");
    display.display();

    Serial.println("\n  1303167045");
    jeda();
  }
  else
  {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);

    display.setCursor(0, 0);
    display.print("Tag NFC tidak");

    display.setCursor(0, 8);
    display.print("dikenali");

    display.setCursor(0, 16);
    display.print(" > Bukan pelanggan");
    display.display();

    Serial.println("\n  Bukan pelanggan");
  }
  Serial.print("");
}

void jeda()
{
  delay(2000);

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);

  display.setCursor(0, 0);
  display.print("> 10K");

  display.setCursor(0, 8);
  display.print("> 20K");
  display.display();

  display.setCursor(0, 16);
  display.print("> 50K");
  display.display();
}