jonathdb

  int readBlock(int blockNumber, byte arrayAddress[]) {
  int largestModulo4Number=blockNumber/4*4;
  int trailerBlock=largestModulo4Number+3;//determine trailer block for the sector

  /*****************************************authentication of the desired block for access***********************************************************/
  byte status = scanner.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, trailerBlock, &key, &(scanner.uid));
  if (status != MFRC522::STATUS_OK) {
         //Serial.print("PCD_Authenticate() failed (read): ");
         //Serial.println(scanner.GetStatusCodeName(status));
         skrivFeilmld();

jonathdb

#include <Adafruit_NeoPixel.h>
#include <LiquidCrystal.h>
#include <SPI.h>//include the SPI bus library
#include <MFRC522.h>//include the RFID reader library


#define SS_PIN 10                          //slave select pin
#define RST_PIN 9                          //reset pin
String name;                              //ID of the RFID-card
int block=2;                              //this is the block number we will read.