pessoal não consigo carregar esse programa no meu arduino.
já reinstalei varias vezes a biblioteca na IDE do Arduino e continua do mesmo jeito.

peguei o programa de um site

#include
#include
#include

#define SS_PIN 10
#define RST_PIN 9
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance.

LiquidCrystal lcd(6, 7, 5, 4, 3, 2);

char st[20];

void setup()
{
Serial.begin(9600); // Inicia a serial
SPI.begin(); // Inicia SPI bus
mfrc522.PCD_Init(); // Inicia MFRC522
Serial.println("Aproxime o seu cartao do leitor...");
Serial.println();
//Define o número de colunas e linhas do LCD:
lcd.begin(16, 2);
mensageminicial();
}

void loop()
{
// Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent())
{
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial())
{
return;
}
//Mostra UID na serial
Serial.print("UID da tag :");
String conteudo= "";
byte letra;
for (byte i = 0; i < mfrc522.uid.size; i++)
{
Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
Serial.print(mfrc522.uid.uidByte[i], HEX);
conteudo.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
conteudo.concat(String(mfrc522.uid.uidByte[i], HEX));
}
Serial.println();
Serial.print("Mensagem : ");
conteudo.toUpperCase();
if (conteudo.substring(1) == "ED 78 03 CA") //UID 1 - Chaveiro
{
Serial.println("Ola FILIPEFLOP !");
Serial.println();
lcd.clear();
lcd.setCursor(0,0);
lcd.print("Ola FILIPEFLOP !");
lcd.setCursor(0,1);
lcd.print("Acesso liberado!");
delay(3000);
mensageminicial();
}

if (conteudo.substring(1) == "BD 9B 06 7D") //UID 2 - Cartao
{
Serial.println("Ola Cartao !");
Serial.println();
lcd.clear();
lcd.setCursor(0,0);
lcd.print("Ola Cartao !");
lcd.setCursor(0,1);
lcd.print("Acesso Negado !");
delay(3000);
mensageminicial();
}
}

void mensageminicial()
{
lcd.clear();
lcd.print(" Aproxime o seu");
lcd.setCursor(0,1);
lcd.print("cartao do leitor");
}

ai aparece a msg na caixa de msg

C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.cpp: In member function 'bool MFRC522::MIFARE_SetUid(byte*, byte, bool)':

C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.cpp:1818:39: warning: 'bool MFRC522::MIFARE_OpenUidBackdoor(bool)' is deprecated (declared at C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.cpp:1674): will move to extra class in next version [-Wdeprecated-declarations]

if (!MIFARE_OpenUidBackdoor(logErrors)) {

^

C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.cpp: In member function 'bool MFRC522::MIFARE_UnbrickUidSector(bool)':

C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.cpp:1847:34: warning: 'bool MFRC522::MIFARE_OpenUidBackdoor(bool)' is deprecated (declared at C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.cpp:1674): will move to extra class in next version [-Wdeprecated-declarations]

MIFARE_OpenUidBackdoor(logErrors);

^

In file included from C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522Extended.cpp:8:0:

C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522Extended.h: In constructor 'MFRC522Extended::MFRC522Extended(uint8_t)':

C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522Extended.h:81:44: warning: 'MFRC522::MFRC522(byte)' is deprecated (declared at C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\MFRC522\src\MFRC522.h:335): use MFRC522(byte chipSelectPin, byte resetPowerDownPin) [-Wdeprecated-declarations]

MFRC522Extended(uint8_t rst) : MFRC522(rst) {};

^

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::begin()'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

c:/users/pca/downloads/documents/arduino-1.6.12-windows/arduino-1.6.12/hardware/tools/avr/bin/../lib/gcc/avr/4.9.2/../../../../avr/bin/ld.exe: Disabling relaxation: it will not work with multiple definitions

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::initialized'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::end()'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::interruptMode'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::usingInterrupt(unsigned char)'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::interruptMask'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::notUsingInterrupt(unsigned char)'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPIClass::interruptSave'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

libraries\SPI\SPI.cpp.o (symbol from plugin): In function `SPIClass::begin()':

(.text+0x0): multiple definition of `SPI'

libraries\SPI\SPI (2).cpp.o (symbol from plugin):(.text+0x0): first defined here

collect2.exe: error: ld returned 1 exit status

Foram encontradas múltiplas bibliotecas para "SPI.h"
Usado: C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\hardware\arduino\avr\libraries\SPI
Não usado: C:\Users\PCA\Downloads\Documents\arduino-1.6.12-windows\arduino-1.6.12\libraries\SPI-master
exit status 1
Erro compilando para a placa Arduino/Genuino Mega or Mega 2560

alguma ajuda