Styjun

I am using RFID-RC522 to read a card with RFID already installed in the arduino, but when using function findCard() in the class RFID, I get an error:
'class RFID' has no member named 'findCard'

I opened the address where RFID.zip exists in my computer(I installed it by downloading a zip file and add it in arduino). I unzipped it and found that there is no function named "findCard".

Then there are two possibilities: my code is error, or RFID that I downloaded is error.

But I checked my code again, it is as same as what has been written in my book. And I searched in the internet to download a second "RFID.zip" from a different place, which, I later found, was as same as what I downloaded first.

my code is as follows. Error is in Line 19, where has a function named "findCard". These code also use some other functions in class RFID, but those can all be successfully found in RFID.

#include <SPI.h>
#include <RFID.h>

//D10 - 读卡器CS引脚、D5 - 读卡器RST引脚
RFID rfid(10, 5);
unsigned char status;
unsigned char str[MAX_LEN]; //MAX_LEN为16，数组最大长度

void setup()

 Serial.begin(9600);
 SPI.begin();
 rfid.init(); //初始化


void loop()

 //Search card, return card types
 if (rfid.findCard(PICC_REQIDL, str) == MI_OK) 
 Serial.println("Find the card!");
 // Show card type
 ShowCardType(str);
 //防冲突检测,读取卡序列号
 if (rfid.anticoll(str) == MI_OK) 
 Serial.print("The card's number is : ");
 //显示卡序列号
 for (int i = 0; i < 4; i++) 
 Serial.print(0x0F & (str[i] >> 4), HEX);
 Serial.print(0x0F & str[i], HEX);
 
 Serial.println("");
 
 //选卡（锁定卡片，防止多数读取，去掉本行将连续读卡）
 rfid.selectTag(str);
 
 rfid.halt(); //命令卡片进入休眠状态


void ShowCardType(unsigned char * type)

 Serial.print("Card type: ");
 if (type[0] == 0x04 && type[1] == 0x00)
 Serial.println("MFOne-S50");
 else if (type[0] == 0x02 && type[1] == 0x00)
 Serial.println("MFOne-S70");
 else if (type[0] == 0x44 && type[1] == 0x00)
 Serial.println("MF-UltraLight");
 else if (type[0] == 0x08 && type[1] == 0x00)
 Serial.println("MF-Pro");
 else if (type[0] == 0x44 && type[1] == 0x03)
 Serial.println("MF Desire");
 else
 Serial.println("Unknown");

RFID.h in RFID.zip are as follows, where there is no function findCard:

/* RFID.h - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI W AND R BY COOQROBOT.
 * Based on code Dr.Leong ( WWW.B2CQSHOP.COM )
 * Created by Miguel Balboa (circuitito.com), Jan, 2012. 
 * 整理者：极客工坊bg1lsy (lsy@sogou.com)
 * 整理时间：2013.05.25
 */
#ifndef RFID_h
#define RFID_h

#include <Arduino.h>
#include <SPI.h>


/******************************************************************************
 * 定义
 ******************************************************************************/
#define MAX_LEN 16 // 数组最大长度

//MF522命令字
#define PCD_IDLE 0x00 //无动作，取消当前命令
#define PCD_AUTHENT 0x0E //验证密钥
#define PCD_RECEIVE 0x08 //接收数据
#define PCD_TRANSMIT 0x04 //发送数据
#define PCD_TRANSCEIVE 0x0C //发送并接收数据
#define PCD_RESETPHASE 0x0F //复位
#define PCD_CALCCRC 0x03 //CRC计算

//Mifare_One卡片命令字
#define PICC_REQIDL 0x26 //寻天线区内未进入休眠状态
#define PICC_REQALL 0x52 //寻天线区内全部卡
#define PICC_ANTICOLL 0x93 //防冲撞
#define PICC_SElECTTAG 0x93 //选卡
#define PICC_AUTHENT1A 0x60 //验证A密钥
#define PICC_AUTHENT1B 0x61 //验证B密钥
#define PICC_READ 0x30 //读块
#define PICC_WRITE 0xA0 //写块
#define PICC_DECREMENT 0xC0 
#define PICC_INCREMENT 0xC1 
#define PICC_RESTORE 0xC2 //调块数据到缓冲区
#define PICC_TRANSFER 0xB0 //保存缓冲区中数据
#define PICC_HALT 0x50 //休眠

//和MF522通讯时返回的错误代码
#define MI_OK 0
#define MI_NOTAGERR 1
#define MI_ERR 2


//------------------MFRC522寄存器---------------
//Page 0:Command and Status
#define Reserved00 0x00 
#define CommandReg 0x01 
#define CommIEnReg 0x02 
#define DivlEnReg 0x03 
#define CommIrqReg 0x04 
#define DivIrqReg 0x05
#define ErrorReg 0x06 
#define Status1Reg 0x07 
#define Status2Reg 0x08 
#define FIFODataReg 0x09
#define FIFOLevelReg 0x0A
#define WaterLevelReg 0x0B
#define ControlReg 0x0C
#define BitFramingReg 0x0D
#define CollReg 0x0E
#define Reserved01 0x0F
//Page 1:Command 
#define Reserved10 0x10
#define ModeReg 0x11
#define TxModeReg 0x12
#define RxModeReg 0x13
#define TxControlReg 0x14
#define TxAutoReg 0x15
#define TxSelReg 0x16
#define RxSelReg 0x17
#define RxThresholdReg 0x18
#define DemodReg 0x19
#define Reserved11 0x1A
#define Reserved12 0x1B
#define MifareReg 0x1C
#define Reserved13 0x1D
#define Reserved14 0x1E
#define SerialSpeedReg 0x1F
//Page 2:CFG 
#define Reserved20 0x20 
#define CRCResultRegM 0x21
#define CRCResultRegL 0x22
#define Reserved21 0x23
#define ModWidthReg 0x24
#define Reserved22 0x25
#define RFCfgReg 0x26
#define GsNReg 0x27
#define CWGsPReg 0x28
#define ModGsPReg 0x29
#define TModeReg 0x2A
#define TPrescalerReg 0x2B
#define TReloadRegH 0x2C
#define TReloadRegL 0x2D
#define TCounterValueRegH 0x2E
#define TCounterValueRegL 0x2F
//Page 3:TestRegister 
#define Reserved30 0x30
#define TestSel1Reg 0x31
#define TestSel2Reg 0x32
#define TestPinEnReg 0x33
#define TestPinValueReg 0x34
#define TestBusReg 0x35
#define AutoTestReg 0x36
#define VersionReg 0x37
#define AnalogTestReg 0x38
#define TestDAC1Reg 0x39 
#define TestDAC2Reg 0x3A 
#define TestADCReg 0x3B 
#define Reserved31 0x3C 
#define Reserved32 0x3D 
#define Reserved33 0x3E 
#define Reserved34 0x3F
//-----------------------------------------------

class RFID

 public:
 RFID(int chipSelectPin, int NRSTPD);

 bool isCard();
 bool readCardSerial();
 void init();
 void reset();
 void setBitMask(unsigned char reg, unsigned char mask);
 void clearBitMask(unsigned char reg, unsigned char mask);
 void antennaOn(void);
 void antennaOff(void);
 void calculateCRC(unsigned char *pIndata, unsigned char len, unsigned char *pOutData);
 void writeMFRC522(unsigned char addr, unsigned char val);
 unsigned char readMFRC522(unsigned char addr);
 unsigned char MFRC522Request(unsigned char reqMode, unsigned char *TagType);
 unsigned char MFRC522ToCard(unsigned char command, unsigned char *sendData, unsigned char sendLen, unsigned char *backData, unsigned int *backLen);
 unsigned char anticoll(unsigned char *serNum);
 unsigned char auth(unsigned char authMode, unsigned char BlockAddr, unsigned char *Sectorkey, unsigned char *serNum);
 unsigned char read(unsigned char blockAddr, unsigned char *recvData);
 unsigned char write(unsigned char blockAddr, unsigned char *writeData);
 unsigned char selectTag(unsigned char *serNum);
 void halt();

 unsigned char serNum[5]; // 4字节卡序列号，第5字节为校验字节

 private:
 int _chipSelectPin;
 int _NRSTPD;
;

#endif

If you want to use the RC522 I suggest you use the library offered in the Arduino IDE.

Click Sketch -> Include Library -> Manage Libraries

Search for 522 and install the library you find. This library is up-to-date, very well tested and specifically written for your RFID-Reader and should support the full feature set of that device.

As Ivan pointed out the library you're using is from 2013 and most likely outdated.