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MFRC522_I2C_Library/MFRC522_I2C.cpp

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2018-06-24 15:54:33 +02:00
/*
* MFRC522.cpp - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS I2C BY AROZCAN
* MFRC522.cpp - Based on ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI Library BY COOQROBOT.
* NOTE: Please also check the comments in MFRC522.h - they provide useful hints and background information.
* Released into the public domain.
Update MFRC522_I2C.cpp
2018-06-24 16:00:14 +02:00
* Author: arozcan @ https://github.com/arozcan/MFRC522-I2C-Library
Add files via upload
2018-06-24 15:54:33 +02:00
*/
#include <Arduino.h>
#include <MFRC522_I2C.h>
#include <Wire.h>
/////////////////////////////////////////////////////////////////////////////////////
// Functions for setting up the Arduino
/////////////////////////////////////////////////////////////////////////////////////
/**
* Constructor.
* Prepares the output pins.
*/
MFRC522::MFRC522( byte chipAddress,
byte resetPowerDownPin ///< Arduino pin connected to MFRC522's reset and power down input (Pin 6, NRSTPD, active low)
) {
_chipAddress = chipAddress;
_resetPowerDownPin = resetPowerDownPin;
} // End constructor
/////////////////////////////////////////////////////////////////////////////////////
// Basic interface functions for communicating with the MFRC522
/////////////////////////////////////////////////////////////////////////////////////
/**
* Writes a byte to the specified register in the MFRC522 chip.
* The interface is described in the datasheet section 8.1.2.
*/
void MFRC522::PCD_WriteRegister( byte reg, ///< The register to write to. One of the PCD_Register enums.
byte value ///< The value to write.
) {
Wire.beginTransmission(_chipAddress);
Wire.write(reg);
Wire.write(value);
Wire.endTransmission();
} // End PCD_WriteRegister()
/**
* Writes a number of bytes to the specified register in the MFRC522 chip.
* The interface is described in the datasheet section 8.1.2.
*/
void MFRC522::PCD_WriteRegister( byte reg, ///< The register to write to. One of the PCD_Register enums.
byte count, ///< The number of bytes to write to the register
byte *values ///< The values to write. Byte array.
) {
Wire.beginTransmission(_chipAddress);
Wire.write(reg);
for (byte index = 0; index < count; index++) {
Wire.write(values[index]);
}
Wire.endTransmission();
} // End PCD_WriteRegister()
/**
* Reads a byte from the specified register in the MFRC522 chip.
* The interface is described in the datasheet section 8.1.2.
*/
byte MFRC522::PCD_ReadRegister( byte reg ///< The register to read from. One of the PCD_Register enums.
) {
byte value;
//digitalWrite(_chipSelectPin, LOW); // Select slave
Wire.beginTransmission(_chipAddress);
Wire.write(reg);
Wire.endTransmission();
Wire.requestFrom(_chipAddress, 1);
value = Wire.read();
return value;
} // End PCD_ReadRegister()
/**
* Reads a number of bytes from the specified register in the MFRC522 chip.
* The interface is described in the datasheet section 8.1.2.
*/
void MFRC522::PCD_ReadRegister( byte reg, ///< The register to read from. One of the PCD_Register enums.
byte count, ///< The number of bytes to read
byte *values, ///< Byte array to store the values in.
byte rxAlign ///< Only bit positions rxAlign..7 in values[0] are updated.
) {
if (count == 0) {
return;
}
byte address = reg;
byte index = 0; // Index in values array.
Wire.beginTransmission(_chipAddress);
Wire.write(address);
Wire.endTransmission();
Wire.requestFrom(_chipAddress, count);
while (Wire.available()) {
if (index == 0 && rxAlign) { // Only update bit positions rxAlign..7 in values[0]
// Create bit mask for bit positions rxAlign..7
byte mask = 0;
for (byte i = rxAlign; i <= 7; i++) {
mask |= (1 << i);
}
// Read value and tell that we want to read the same address again.
byte value = Wire.read();
// Apply mask to both current value of values[0] and the new data in value.
values[0] = (values[index] & ~mask) | (value & mask);
}
else { // Normal case
values[index] = Wire.read();
}
index++;
}
} // End PCD_ReadRegister()
/**
* Sets the bits given in mask in register reg.
*/
void MFRC522::PCD_SetRegisterBitMask( byte reg, ///< The register to update. One of the PCD_Register enums.
byte mask ///< The bits to set.
) {
byte tmp;
tmp = PCD_ReadRegister(reg);
PCD_WriteRegister(reg, tmp | mask); // set bit mask
} // End PCD_SetRegisterBitMask()
/**
* Clears the bits given in mask from register reg.
*/
void MFRC522::PCD_ClearRegisterBitMask( byte reg, ///< The register to update. One of the PCD_Register enums.
byte mask ///< The bits to clear.
) {
byte tmp;
tmp = PCD_ReadRegister(reg);
PCD_WriteRegister(reg, tmp & (~mask)); // clear bit mask
} // End PCD_ClearRegisterBitMask()
/**
* Use the CRC coprocessor in the MFRC522 to calculate a CRC_A.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PCD_CalculateCRC( byte *data, ///< In: Pointer to the data to transfer to the FIFO for CRC calculation.
byte length, ///< In: The number of bytes to transfer.
byte *result ///< Out: Pointer to result buffer. Result is written to result[0..1], low byte first.
) {
PCD_WriteRegister(CommandReg, PCD_Idle); // Stop any active command.
PCD_WriteRegister(DivIrqReg, 0x04); // Clear the CRCIRq interrupt request bit
PCD_SetRegisterBitMask(FIFOLevelReg, 0x80); // FlushBuffer = 1, FIFO initialization
PCD_WriteRegister(FIFODataReg, length, data); // Write data to the FIFO
PCD_WriteRegister(CommandReg, PCD_CalcCRC); // Start the calculation
// Wait for the CRC calculation to complete. Each iteration of the while-loop takes 17.73<EFBFBD>s.
word i = 5000;
byte n;
while (1) {
n = PCD_ReadRegister(DivIrqReg); // DivIrqReg[7..0] bits are: Set2 reserved reserved MfinActIRq reserved CRCIRq reserved reserved
if (n & 0x04) { // CRCIRq bit set - calculation done
break;
}
if (--i == 0) { // The emergency break. We will eventually terminate on this one after 89ms. Communication with the MFRC522 might be down.
return STATUS_TIMEOUT;
}
}
PCD_WriteRegister(CommandReg, PCD_Idle); // Stop calculating CRC for new content in the FIFO.
// Transfer the result from the registers to the result buffer
result[0] = PCD_ReadRegister(CRCResultRegL);
result[1] = PCD_ReadRegister(CRCResultRegH);
return STATUS_OK;
} // End PCD_CalculateCRC()
/////////////////////////////////////////////////////////////////////////////////////
// Functions for manipulating the MFRC522
/////////////////////////////////////////////////////////////////////////////////////
/**
* Initializes the MFRC522 chip.
*/
void MFRC522::PCD_Init() {
// Set the chipSelectPin as digital output, do not select the slave yet
// Set the resetPowerDownPin as digital output, do not reset or power down.
pinMode(_resetPowerDownPin, OUTPUT);
if (digitalRead(_resetPowerDownPin) == LOW) { //The MFRC522 chip is in power down mode.
digitalWrite(_resetPowerDownPin, HIGH); // Exit power down mode. This triggers a hard reset.
// Section 8.8.2 in the datasheet says the oscillator start-up time is the start up time of the crystal + 37,74<37>s. Let us be generous: 50ms.
delay(50);
}
else { // Perform a soft reset
PCD_Reset();
}
// When communicating with a PICC we need a timeout if something goes wrong.
// f_timer = 13.56 MHz / (2*TPreScaler+1) where TPreScaler = [TPrescaler_Hi:TPrescaler_Lo].
// TPrescaler_Hi are the four low bits in TModeReg. TPrescaler_Lo is TPrescalerReg.
PCD_WriteRegister(TModeReg, 0x80); // TAuto=1; timer starts automatically at the end of the transmission in all communication modes at all speeds
PCD_WriteRegister(TPrescalerReg, 0xA9); // TPreScaler = TModeReg[3..0]:TPrescalerReg, ie 0x0A9 = 169 => f_timer=40kHz, ie a timer period of 25<32>s.
PCD_WriteRegister(TReloadRegH, 0x03); // Reload timer with 0x3E8 = 1000, ie 25ms before timeout.
PCD_WriteRegister(TReloadRegL, 0xE8);
PCD_WriteRegister(TxASKReg, 0x40); // Default 0x00. Force a 100 % ASK modulation independent of the ModGsPReg register setting
PCD_WriteRegister(ModeReg, 0x3D); // Default 0x3F. Set the preset value for the CRC coprocessor for the CalcCRC command to 0x6363 (ISO 14443-3 part 6.2.4)
PCD_AntennaOn(); // Enable the antenna driver pins TX1 and TX2 (they were disabled by the reset)
} // End PCD_Init()
/**
* Performs a soft reset on the MFRC522 chip and waits for it to be ready again.
*/
void MFRC522::PCD_Reset() {
PCD_WriteRegister(CommandReg, PCD_SoftReset); // Issue the SoftReset command.
// The datasheet does not mention how long the SoftRest command takes to complete.
// But the MFRC522 might have been in soft power-down mode (triggered by bit 4 of CommandReg)
// Section 8.8.2 in the datasheet says the oscillator start-up time is the start up time of the crystal + 37,74<37>s. Let us be generous: 50ms.
delay(50);
// Wait for the PowerDown bit in CommandReg to be cleared
while (PCD_ReadRegister(CommandReg) & (1<<4)) {
// PCD still restarting - unlikely after waiting 50ms, but better safe than sorry.
}
} // End PCD_Reset()
/**
* Turns the antenna on by enabling pins TX1 and TX2.
* After a reset these pins are disabled.
*/
void MFRC522::PCD_AntennaOn() {
byte value = PCD_ReadRegister(TxControlReg);
if ((value & 0x03) != 0x03) {
PCD_WriteRegister(TxControlReg, value | 0x03);
}
} // End PCD_AntennaOn()
/**
* Turns the antenna off by disabling pins TX1 and TX2.
*/
void MFRC522::PCD_AntennaOff() {
PCD_ClearRegisterBitMask(TxControlReg, 0x03);
} // End PCD_AntennaOff()
/**
* Get the current MFRC522 Receiver Gain (RxGain[2:0]) value.
* See 9.3.3.6 / table 98 in http://www.nxp.com/documents/data_sheet/MFRC522.pdf
* NOTE: Return value scrubbed with (0x07<<4)=01110000b as RCFfgReg may use reserved bits.
*
* @return Value of the RxGain, scrubbed to the 3 bits used.
*/
byte MFRC522::PCD_GetAntennaGain() {
return PCD_ReadRegister(RFCfgReg) & (0x07<<4);
} // End PCD_GetAntennaGain()
/**
* Set the MFRC522 Receiver Gain (RxGain) to value specified by given mask.
* See 9.3.3.6 / table 98 in http://www.nxp.com/documents/data_sheet/MFRC522.pdf
* NOTE: Given mask is scrubbed with (0x07<<4)=01110000b as RCFfgReg may use reserved bits.
*/
void MFRC522::PCD_SetAntennaGain(byte mask) {
if (PCD_GetAntennaGain() != mask) { // only bother if there is a change
PCD_ClearRegisterBitMask(RFCfgReg, (0x07<<4)); // clear needed to allow 000 pattern
PCD_SetRegisterBitMask(RFCfgReg, mask & (0x07<<4)); // only set RxGain[2:0] bits
}
} // End PCD_SetAntennaGain()
/**
* Performs a self-test of the MFRC522
* See 16.1.1 in http://www.nxp.com/documents/data_sheet/MFRC522.pdf
*
* @return Whether or not the test passed.
*/
bool MFRC522::PCD_PerformSelfTest() {
// This follows directly the steps outlined in 16.1.1
// 1. Perform a soft reset.
PCD_Reset();
// 2. Clear the internal buffer by writing 25 bytes of 00h
byte ZEROES[25] = {0x00};
PCD_SetRegisterBitMask(FIFOLevelReg, 0x80); // flush the FIFO buffer
PCD_WriteRegister(FIFODataReg, 25, ZEROES); // write 25 bytes of 00h to FIFO
PCD_WriteRegister(CommandReg, PCD_Mem); // transfer to internal buffer
// 3. Enable self-test
PCD_WriteRegister(AutoTestReg, 0x09);
// 4. Write 00h to FIFO buffer
PCD_WriteRegister(FIFODataReg, 0x00);
// 5. Start self-test by issuing the CalcCRC command
PCD_WriteRegister(CommandReg, PCD_CalcCRC);
// 6. Wait for self-test to complete
word i;
byte n;
for (i = 0; i < 0xFF; i++) {
n = PCD_ReadRegister(DivIrqReg); // DivIrqReg[7..0] bits are: Set2 reserved reserved MfinActIRq reserved CRCIRq reserved reserved
if (n & 0x04) { // CRCIRq bit set - calculation done
break;
}
}
PCD_WriteRegister(CommandReg, PCD_Idle); // Stop calculating CRC for new content in the FIFO.
// 7. Read out resulting 64 bytes from the FIFO buffer.
byte result[64];
PCD_ReadRegister(FIFODataReg, 64, result, 0);
// Auto self-test done
// Reset AutoTestReg register to be 0 again. Required for normal operation.
PCD_WriteRegister(AutoTestReg, 0x00);
// Determine firmware version (see section 9.3.4.8 in spec)
byte version = PCD_ReadRegister(VersionReg);
// Pick the appropriate reference values
const byte *reference;
switch (version) {
case 0x88: // Fudan Semiconductor FM17522 clone
reference = FM17522_firmware_reference;
break;
case 0x90: // Version 0.0
reference = MFRC522_firmware_referenceV0_0;
break;
case 0x91: // Version 1.0
reference = MFRC522_firmware_referenceV1_0;
break;
case 0x92: // Version 2.0
reference = MFRC522_firmware_referenceV2_0;
break;
default: // Unknown version
return false;
}
// Verify that the results match up to our expectations
for (i = 0; i < 64; i++) {
if (result[i] != pgm_read_byte(&(reference[i]))) {
return false;
}
}
// Test passed; all is good.
return true;
} // End PCD_PerformSelfTest()
/////////////////////////////////////////////////////////////////////////////////////
// Functions for communicating with PICCs
/////////////////////////////////////////////////////////////////////////////////////
/**
* Executes the Transceive command.
* CRC validation can only be done if backData and backLen are specified.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PCD_TransceiveData( byte *sendData, ///< Pointer to the data to transfer to the FIFO.
byte sendLen, ///< Number of bytes to transfer to the FIFO.
byte *backData, ///< NULL or pointer to buffer if data should be read back after executing the command.
byte *backLen, ///< In: Max number of bytes to write to *backData. Out: The number of bytes returned.
byte *validBits, ///< In/Out: The number of valid bits in the last byte. 0 for 8 valid bits. Default NULL.
byte rxAlign, ///< In: Defines the bit position in backData[0] for the first bit received. Default 0.
bool checkCRC ///< In: True => The last two bytes of the response is assumed to be a CRC_A that must be validated.
) {
byte waitIRq = 0x30; // RxIRq and IdleIRq
return PCD_CommunicateWithPICC(PCD_Transceive, waitIRq, sendData, sendLen, backData, backLen, validBits, rxAlign, checkCRC);
} // End PCD_TransceiveData()
/**
* Transfers data to the MFRC522 FIFO, executes a command, waits for completion and transfers data back from the FIFO.
* CRC validation can only be done if backData and backLen are specified.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PCD_CommunicateWithPICC( byte command, ///< The command to execute. One of the PCD_Command enums.
byte waitIRq, ///< The bits in the ComIrqReg register that signals successful completion of the command.
byte *sendData, ///< Pointer to the data to transfer to the FIFO.
byte sendLen, ///< Number of bytes to transfer to the FIFO.
byte *backData, ///< NULL or pointer to buffer if data should be read back after executing the command.
byte *backLen, ///< In: Max number of bytes to write to *backData. Out: The number of bytes returned.
byte *validBits, ///< In/Out: The number of valid bits in the last byte. 0 for 8 valid bits.
byte rxAlign, ///< In: Defines the bit position in backData[0] for the first bit received. Default 0.
bool checkCRC ///< In: True => The last two bytes of the response is assumed to be a CRC_A that must be validated.
) {
byte n, _validBits;
unsigned int i;
// Prepare values for BitFramingReg
byte txLastBits = validBits ? *validBits : 0;
byte bitFraming = (rxAlign << 4) + txLastBits; // RxAlign = BitFramingReg[6..4]. TxLastBits = BitFramingReg[2..0]
PCD_WriteRegister(CommandReg, PCD_Idle); // Stop any active command.
PCD_WriteRegister(ComIrqReg, 0x7F); // Clear all seven interrupt request bits
PCD_SetRegisterBitMask(FIFOLevelReg, 0x80); // FlushBuffer = 1, FIFO initialization
PCD_WriteRegister(FIFODataReg, sendLen, sendData); // Write sendData to the FIFO
PCD_WriteRegister(BitFramingReg, bitFraming); // Bit adjustments
PCD_WriteRegister(CommandReg, command); // Execute the command
if (command == PCD_Transceive) {
PCD_SetRegisterBitMask(BitFramingReg, 0x80); // StartSend=1, transmission of data starts
}
// Wait for the command to complete.
// In PCD_Init() we set the TAuto flag in TModeReg. This means the timer automatically starts when the PCD stops transmitting.
// Each iteration of the do-while-loop takes 17.86<EFBFBD>s.
i = 2000;
while (1) {
n = PCD_ReadRegister(ComIrqReg); // ComIrqReg[7..0] bits are: Set1 TxIRq RxIRq IdleIRq HiAlertIRq LoAlertIRq ErrIRq TimerIRq
if (n & waitIRq) { // One of the interrupts that signal success has been set.
break;
}
if (n & 0x01) { // Timer interrupt - nothing received in 25ms
return STATUS_TIMEOUT;
}
if (--i == 0) { // The emergency break. If all other condions fail we will eventually terminate on this one after 35.7ms. Communication with the MFRC522 might be down.
return STATUS_TIMEOUT;
}
}
// Stop now if any errors except collisions were detected.
byte errorRegValue = PCD_ReadRegister(ErrorReg); // ErrorReg[7..0] bits are: WrErr TempErr reserved BufferOvfl CollErr CRCErr ParityErr ProtocolErr
if (errorRegValue & 0x13) { // BufferOvfl ParityErr ProtocolErr
return STATUS_ERROR;
}
// If the caller wants data back, get it from the MFRC522.
if (backData && backLen) {
n = PCD_ReadRegister(FIFOLevelReg); // Number of bytes in the FIFO
if (n > *backLen) {
return STATUS_NO_ROOM;
}
*backLen = n; // Number of bytes returned
PCD_ReadRegister(FIFODataReg, n, backData, rxAlign); // Get received data from FIFO
_validBits = PCD_ReadRegister(ControlReg) & 0x07; // RxLastBits[2:0] indicates the number of valid bits in the last received byte. If this value is 000b, the whole byte is valid.
if (validBits) {
*validBits = _validBits;
}
}
// Tell about collisions
if (errorRegValue & 0x08) { // CollErr
return STATUS_COLLISION;
}
// Perform CRC_A validation if requested.
if (backData && backLen && checkCRC) {
// In this case a MIFARE Classic NAK is not OK.
if (*backLen == 1 && _validBits == 4) {
return STATUS_MIFARE_NACK;
}
// We need at least the CRC_A value and all 8 bits of the last byte must be received.
if (*backLen < 2 || _validBits != 0) {
return STATUS_CRC_WRONG;
}
// Verify CRC_A - do our own calculation and store the control in controlBuffer.
byte controlBuffer[2];
n = PCD_CalculateCRC(&backData[0], *backLen - 2, &controlBuffer[0]);
if (n != STATUS_OK) {
return n;
}
if ((backData[*backLen - 2] != controlBuffer[0]) || (backData[*backLen - 1] != controlBuffer[1])) {
return STATUS_CRC_WRONG;
}
}
return STATUS_OK;
} // End PCD_CommunicateWithPICC()
/**
* Transmits a REQuest command, Type A. Invites PICCs in state IDLE to go to READY and prepare for anticollision or selection. 7 bit frame.
* Beware: When two PICCs are in the field at the same time I often get STATUS_TIMEOUT - probably due do bad antenna design.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PICC_RequestA(byte *bufferATQA, ///< The buffer to store the ATQA (Answer to request) in
byte *bufferSize ///< Buffer size, at least two bytes. Also number of bytes returned if STATUS_OK.
) {
return PICC_REQA_or_WUPA(PICC_CMD_REQA, bufferATQA, bufferSize);
} // End PICC_RequestA()
/**
* Transmits a Wake-UP command, Type A. Invites PICCs in state IDLE and HALT to go to READY(*) and prepare for anticollision or selection. 7 bit frame.
* Beware: When two PICCs are in the field at the same time I often get STATUS_TIMEOUT - probably due do bad antenna design.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PICC_WakeupA( byte *bufferATQA, ///< The buffer to store the ATQA (Answer to request) in
byte *bufferSize ///< Buffer size, at least two bytes. Also number of bytes returned if STATUS_OK.
) {
return PICC_REQA_or_WUPA(PICC_CMD_WUPA, bufferATQA, bufferSize);
} // End PICC_WakeupA()
/**
* Transmits REQA or WUPA commands.
* Beware: When two PICCs are in the field at the same time I often get STATUS_TIMEOUT - probably due do bad antenna design.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PICC_REQA_or_WUPA( byte command, ///< The command to send - PICC_CMD_REQA or PICC_CMD_WUPA
byte *bufferATQA, ///< The buffer to store the ATQA (Answer to request) in
byte *bufferSize ///< Buffer size, at least two bytes. Also number of bytes returned if STATUS_OK.
) {
byte validBits;
byte status;
if (bufferATQA == NULL || *bufferSize < 2) { // The ATQA response is 2 bytes long.
return STATUS_NO_ROOM;
}
PCD_ClearRegisterBitMask(CollReg, 0x80); // ValuesAfterColl=1 => Bits received after collision are cleared.
validBits = 7; // For REQA and WUPA we need the short frame format - transmit only 7 bits of the last (and only) byte. TxLastBits = BitFramingReg[2..0]
status = PCD_TransceiveData(&command, 1, bufferATQA, bufferSize, &validBits);
if (status != STATUS_OK) {
return status;
}
if (*bufferSize != 2 || validBits != 0) { // ATQA must be exactly 16 bits.
return STATUS_ERROR;
}
return STATUS_OK;
} // End PICC_REQA_or_WUPA()
/**
* Transmits SELECT/ANTICOLLISION commands to select a single PICC.
* Before calling this function the PICCs must be placed in the READY(*) state by calling PICC_RequestA() or PICC_WakeupA().
* On success:
* - The chosen PICC is in state ACTIVE(*) and all other PICCs have returned to state IDLE/HALT. (Figure 7 of the ISO/IEC 14443-3 draft.)
* - The UID size and value of the chosen PICC is returned in *uid along with the SAK.
*
* A PICC UID consists of 4, 7 or 10 bytes.
* Only 4 bytes can be specified in a SELECT command, so for the longer UIDs two or three iterations are used:
* UID size Number of UID bytes Cascade levels Example of PICC
* ======== =================== ============== ===============
* single 4 1 MIFARE Classic
* double 7 2 MIFARE Ultralight
* triple 10 3 Not currently in use?
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PICC_Select( Uid *uid, ///< Pointer to Uid struct. Normally output, but can also be used to supply a known UID.
byte validBits ///< The number of known UID bits supplied in *uid. Normally 0. If set you must also supply uid->size.
) {
bool uidComplete;
bool selectDone;
bool useCascadeTag;
byte cascadeLevel = 1;
byte result;
byte count;
byte index;
byte uidIndex; // The first index in uid->uidByte[] that is used in the current Cascade Level.
int8_t currentLevelKnownBits; // The number of known UID bits in the current Cascade Level.
byte buffer[9]; // The SELECT/ANTICOLLISION commands uses a 7 byte standard frame + 2 bytes CRC_A
byte bufferUsed; // The number of bytes used in the buffer, ie the number of bytes to transfer to the FIFO.
byte rxAlign; // Used in BitFramingReg. Defines the bit position for the first bit received.
byte txLastBits; // Used in BitFramingReg. The number of valid bits in the last transmitted byte.
byte *responseBuffer;
byte responseLength;
// Description of buffer structure:
// Byte 0: SEL Indicates the Cascade Level: PICC_CMD_SEL_CL1, PICC_CMD_SEL_CL2 or PICC_CMD_SEL_CL3
// Byte 1: NVB Number of Valid Bits (in complete command, not just the UID): High nibble: complete bytes, Low nibble: Extra bits.
// Byte 2: UID-data or CT See explanation below. CT means Cascade Tag.
// Byte 3: UID-data
// Byte 4: UID-data
// Byte 5: UID-data
// Byte 6: BCC Block Check Character - XOR of bytes 2-5
// Byte 7: CRC_A
// Byte 8: CRC_A
// The BCC and CRC_A is only transmitted if we know all the UID bits of the current Cascade Level.
//
// Description of bytes 2-5: (Section 6.5.4 of the ISO/IEC 14443-3 draft: UID contents and cascade levels)
// UID size Cascade level Byte2 Byte3 Byte4 Byte5
// ======== ============= ===== ===== ===== =====
// 4 bytes 1 uid0 uid1 uid2 uid3
// 7 bytes 1 CT uid0 uid1 uid2
// 2 uid3 uid4 uid5 uid6
// 10 bytes 1 CT uid0 uid1 uid2
// 2 CT uid3 uid4 uid5
// 3 uid6 uid7 uid8 uid9
// Sanity checks
if (validBits > 80) {
return STATUS_INVALID;
}
// Prepare MFRC522
PCD_ClearRegisterBitMask(CollReg, 0x80); // ValuesAfterColl=1 => Bits received after collision are cleared.
// Repeat Cascade Level loop until we have a complete UID.
uidComplete = false;
while (!uidComplete) {
// Set the Cascade Level in the SEL byte, find out if we need to use the Cascade Tag in byte 2.
switch (cascadeLevel) {
case 1:
buffer[0] = PICC_CMD_SEL_CL1;
uidIndex = 0;
useCascadeTag = validBits && uid->size > 4; // When we know that the UID has more than 4 bytes
break;
case 2:
buffer[0] = PICC_CMD_SEL_CL2;
uidIndex = 3;
useCascadeTag = validBits && uid->size > 7; // When we know that the UID has more than 7 bytes
break;
case 3:
buffer[0] = PICC_CMD_SEL_CL3;
uidIndex = 6;
useCascadeTag = false; // Never used in CL3.
break;
default:
return STATUS_INTERNAL_ERROR;
break;
}
// How many UID bits are known in this Cascade Level?
currentLevelKnownBits = validBits - (8 * uidIndex);
if (currentLevelKnownBits < 0) {
currentLevelKnownBits = 0;
}
// Copy the known bits from uid->uidByte[] to buffer[]
index = 2; // destination index in buffer[]
if (useCascadeTag) {
buffer[index++] = PICC_CMD_CT;
}
byte bytesToCopy = currentLevelKnownBits / 8 + (currentLevelKnownBits % 8 ? 1 : 0); // The number of bytes needed to represent the known bits for this level.
if (bytesToCopy) {
byte maxBytes = useCascadeTag ? 3 : 4; // Max 4 bytes in each Cascade Level. Only 3 left if we use the Cascade Tag
if (bytesToCopy > maxBytes) {
bytesToCopy = maxBytes;
}
for (count = 0; count < bytesToCopy; count++) {
buffer[index++] = uid->uidByte[uidIndex + count];
}
}
// Now that the data has been copied we need to include the 8 bits in CT in currentLevelKnownBits
if (useCascadeTag) {
currentLevelKnownBits += 8;
}
// Repeat anti collision loop until we can transmit all UID bits + BCC and receive a SAK - max 32 iterations.
selectDone = false;
while (!selectDone) {
// Find out how many bits and bytes to send and receive.
if (currentLevelKnownBits >= 32) { // All UID bits in this Cascade Level are known. This is a SELECT.
//Serial.print(F("SELECT: currentLevelKnownBits=")); Serial.println(currentLevelKnownBits, DEC);
buffer[1] = 0x70; // NVB - Number of Valid Bits: Seven whole bytes
// Calculate BCC - Block Check Character
buffer[6] = buffer[2] ^ buffer[3] ^ buffer[4] ^ buffer[5];
// Calculate CRC_A
result = PCD_CalculateCRC(buffer, 7, &buffer[7]);
if (result != STATUS_OK) {
return result;
}
txLastBits = 0; // 0 => All 8 bits are valid.
bufferUsed = 9;
// Store response in the last 3 bytes of buffer (BCC and CRC_A - not needed after tx)
responseBuffer = &buffer[6];
responseLength = 3;
}
else { // This is an ANTICOLLISION.
//Serial.print(F("ANTICOLLISION: currentLevelKnownBits=")); Serial.println(currentLevelKnownBits, DEC);
txLastBits = currentLevelKnownBits % 8;
count = currentLevelKnownBits / 8; // Number of whole bytes in the UID part.
index = 2 + count; // Number of whole bytes: SEL + NVB + UIDs
buffer[1] = (index << 4) + txLastBits; // NVB - Number of Valid Bits
bufferUsed = index + (txLastBits ? 1 : 0);
// Store response in the unused part of buffer
responseBuffer = &buffer[index];
responseLength = sizeof(buffer) - index;
}
// Set bit adjustments
rxAlign = txLastBits; // Having a seperate variable is overkill. But it makes the next line easier to read.
PCD_WriteRegister(BitFramingReg, (rxAlign << 4) + txLastBits); // RxAlign = BitFramingReg[6..4]. TxLastBits = BitFramingReg[2..0]
// Transmit the buffer and receive the response.
result = PCD_TransceiveData(buffer, bufferUsed, responseBuffer, &responseLength, &txLastBits, rxAlign);
if (result == STATUS_COLLISION) { // More than one PICC in the field => collision.
result = PCD_ReadRegister(CollReg); // CollReg[7..0] bits are: ValuesAfterColl reserved CollPosNotValid CollPos[4:0]
if (result & 0x20) { // CollPosNotValid
return STATUS_COLLISION; // Without a valid collision position we cannot continue
}
byte collisionPos = result & 0x1F; // Values 0-31, 0 means bit 32.
if (collisionPos == 0) {
collisionPos = 32;
}
if (collisionPos <= currentLevelKnownBits) { // No progress - should not happen
return STATUS_INTERNAL_ERROR;
}
// Choose the PICC with the bit set.
currentLevelKnownBits = collisionPos;
count = (currentLevelKnownBits - 1) % 8; // The bit to modify
index = 1 + (currentLevelKnownBits / 8) + (count ? 1 : 0); // First byte is index 0.
buffer[index] |= (1 << count);
}
else if (result != STATUS_OK) {
return result;
}
else { // STATUS_OK
if (currentLevelKnownBits >= 32) { // This was a SELECT.
selectDone = true; // No more anticollision
// We continue below outside the while.
}
else { // This was an ANTICOLLISION.
// We now have all 32 bits of the UID in this Cascade Level
currentLevelKnownBits = 32;
// Run loop again to do the SELECT.
}
}
} // End of while (!selectDone)
// We do not check the CBB - it was constructed by us above.
// Copy the found UID bytes from buffer[] to uid->uidByte[]
index = (buffer[2] == PICC_CMD_CT) ? 3 : 2; // source index in buffer[]
bytesToCopy = (buffer[2] == PICC_CMD_CT) ? 3 : 4;
for (count = 0; count < bytesToCopy; count++) {
uid->uidByte[uidIndex + count] = buffer[index++];
}
// Check response SAK (Select Acknowledge)
if (responseLength != 3 || txLastBits != 0) { // SAK must be exactly 24 bits (1 byte + CRC_A).
return STATUS_ERROR;
}
// Verify CRC_A - do our own calculation and store the control in buffer[2..3] - those bytes are not needed anymore.
result = PCD_CalculateCRC(responseBuffer, 1, &buffer[2]);
if (result != STATUS_OK) {
return result;
}
if ((buffer[2] != responseBuffer[1]) || (buffer[3] != responseBuffer[2])) {
return STATUS_CRC_WRONG;
}
if (responseBuffer[0] & 0x04) { // Cascade bit set - UID not complete yes
cascadeLevel++;
}
else {
uidComplete = true;
uid->sak = responseBuffer[0];
}
} // End of while (!uidComplete)
// Set correct uid->size
uid->size = 3 * cascadeLevel + 1;
return STATUS_OK;
} // End PICC_Select()
/**
* Instructs a PICC in state ACTIVE(*) to go to state HALT.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PICC_HaltA() {
byte result;
byte buffer[4];
// Build command buffer
buffer[0] = PICC_CMD_HLTA;
buffer[1] = 0;
// Calculate CRC_A
result = PCD_CalculateCRC(buffer, 2, &buffer[2]);
if (result != STATUS_OK) {
return result;
}
// Send the command.
// The standard says:
// If the PICC responds with any modulation during a period of 1 ms after the end of the frame containing the
// HLTA command, this response shall be interpreted as 'not acknowledge'.
// We interpret that this way: Only STATUS_TIMEOUT is an success.
result = PCD_TransceiveData(buffer, sizeof(buffer), NULL, 0);
if (result == STATUS_TIMEOUT) {
return STATUS_OK;
}
if (result == STATUS_OK) { // That is ironically NOT ok in this case ;-)
return STATUS_ERROR;
}
return result;
} // End PICC_HaltA()
/////////////////////////////////////////////////////////////////////////////////////
// Functions for communicating with MIFARE PICCs
/////////////////////////////////////////////////////////////////////////////////////
/**
* Executes the MFRC522 MFAuthent command.
* This command manages MIFARE authentication to enable a secure communication to any MIFARE Mini, MIFARE 1K and MIFARE 4K card.
* The authentication is described in the MFRC522 datasheet section 10.3.1.9 and http://www.nxp.com/documents/data_sheet/MF1S503x.pdf section 10.1.
* For use with MIFARE Classic PICCs.
* The PICC must be selected - ie in state ACTIVE(*) - before calling this function.
* Remember to call PCD_StopCrypto1() after communicating with the authenticated PICC - otherwise no new communications can start.
*
* All keys are set to FFFFFFFFFFFFh at chip delivery.
*
* @return STATUS_OK on success, STATUS_??? otherwise. Probably STATUS_TIMEOUT if you supply the wrong key.
*/
byte MFRC522::PCD_Authenticate(byte command, ///< PICC_CMD_MF_AUTH_KEY_A or PICC_CMD_MF_AUTH_KEY_B
byte blockAddr, ///< The block number. See numbering in the comments in the .h file.
MIFARE_Key *key, ///< Pointer to the Crypteo1 key to use (6 bytes)
Uid *uid ///< Pointer to Uid struct. The first 4 bytes of the UID is used.
) {
byte waitIRq = 0x10; // IdleIRq
// Build command buffer
byte sendData[12];
sendData[0] = command;
sendData[1] = blockAddr;
for (byte i = 0; i < MF_KEY_SIZE; i++) { // 6 key bytes
sendData[2+i] = key->keyByte[i];
}
for (byte i = 0; i < 4; i++) { // The first 4 bytes of the UID
sendData[8+i] = uid->uidByte[i];
}
// Start the authentication.
return PCD_CommunicateWithPICC(PCD_MFAuthent, waitIRq, &sendData[0], sizeof(sendData));
} // End PCD_Authenticate()
/**
* Used to exit the PCD from its authenticated state.
* Remember to call this function after communicating with an authenticated PICC - otherwise no new communications can start.
*/
void MFRC522::PCD_StopCrypto1() {
// Clear MFCrypto1On bit
PCD_ClearRegisterBitMask(Status2Reg, 0x08); // Status2Reg[7..0] bits are: TempSensClear I2CForceHS reserved reserved MFCrypto1On ModemState[2:0]
} // End PCD_StopCrypto1()
/**
* Reads 16 bytes (+ 2 bytes CRC_A) from the active PICC.
*
* For MIFARE Classic the sector containing the block must be authenticated before calling this function.
*
* For MIFARE Ultralight only addresses 00h to 0Fh are decoded.
* The MF0ICU1 returns a NAK for higher addresses.
* The MF0ICU1 responds to the READ command by sending 16 bytes starting from the page address defined by the command argument.
* For example; if blockAddr is 03h then pages 03h, 04h, 05h, 06h are returned.
* A roll-back is implemented: If blockAddr is 0Eh, then the contents of pages 0Eh, 0Fh, 00h and 01h are returned.
*
* The buffer must be at least 18 bytes because a CRC_A is also returned.
* Checks the CRC_A before returning STATUS_OK.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Read( byte blockAddr, ///< MIFARE Classic: The block (0-0xff) number. MIFARE Ultralight: The first page to return data from.
byte *buffer, ///< The buffer to store the data in
byte *bufferSize ///< Buffer size, at least 18 bytes. Also number of bytes returned if STATUS_OK.
) {
byte result;
// Sanity check
if (buffer == NULL || *bufferSize < 18) {
return STATUS_NO_ROOM;
}
// Build command buffer
buffer[0] = PICC_CMD_MF_READ;
buffer[1] = blockAddr;
// Calculate CRC_A
result = PCD_CalculateCRC(buffer, 2, &buffer[2]);
if (result != STATUS_OK) {
return result;
}
// Transmit the buffer and receive the response, validate CRC_A.
return PCD_TransceiveData(buffer, 4, buffer, bufferSize, NULL, 0, true);
} // End MIFARE_Read()
/**
* Writes 16 bytes to the active PICC.
*
* For MIFARE Classic the sector containing the block must be authenticated before calling this function.
*
* For MIFARE Ultralight the operation is called "COMPATIBILITY WRITE".
* Even though 16 bytes are transferred to the Ultralight PICC, only the least significant 4 bytes (bytes 0 to 3)
* are written to the specified address. It is recommended to set the remaining bytes 04h to 0Fh to all logic 0.
* *
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Write( byte blockAddr, ///< MIFARE Classic: The block (0-0xff) number. MIFARE Ultralight: The page (2-15) to write to.
byte *buffer, ///< The 16 bytes to write to the PICC
byte bufferSize ///< Buffer size, must be at least 16 bytes. Exactly 16 bytes are written.
) {
byte result;
// Sanity check
if (buffer == NULL || bufferSize < 16) {
return STATUS_INVALID;
}
// Mifare Classic protocol requires two communications to perform a write.
// Step 1: Tell the PICC we want to write to block blockAddr.
byte cmdBuffer[2];
cmdBuffer[0] = PICC_CMD_MF_WRITE;
cmdBuffer[1] = blockAddr;
result = PCD_MIFARE_Transceive(cmdBuffer, 2); // Adds CRC_A and checks that the response is MF_ACK.
if (result != STATUS_OK) {
return result;
}
// Step 2: Transfer the data
result = PCD_MIFARE_Transceive(buffer, bufferSize); // Adds CRC_A and checks that the response is MF_ACK.
if (result != STATUS_OK) {
return result;
}
return STATUS_OK;
} // End MIFARE_Write()
/**
* Writes a 4 byte page to the active MIFARE Ultralight PICC.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Ultralight_Write( byte page, ///< The page (2-15) to write to.
byte *buffer, ///< The 4 bytes to write to the PICC
byte bufferSize ///< Buffer size, must be at least 4 bytes. Exactly 4 bytes are written.
) {
byte result;
// Sanity check
if (buffer == NULL || bufferSize < 4) {
return STATUS_INVALID;
}
// Build commmand buffer
byte cmdBuffer[6];
cmdBuffer[0] = PICC_CMD_UL_WRITE;
cmdBuffer[1] = page;
memcpy(&cmdBuffer[2], buffer, 4);
// Perform the write
result = PCD_MIFARE_Transceive(cmdBuffer, 6); // Adds CRC_A and checks that the response is MF_ACK.
if (result != STATUS_OK) {
return result;
}
return STATUS_OK;
} // End MIFARE_Ultralight_Write()
/**
* MIFARE Decrement subtracts the delta from the value of the addressed block, and stores the result in a volatile memory.
* For MIFARE Classic only. The sector containing the block must be authenticated before calling this function.
* Only for blocks in "value block" mode, ie with access bits [C1 C2 C3] = [110] or [001].
* Use MIFARE_Transfer() to store the result in a block.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Decrement( byte blockAddr, ///< The block (0-0xff) number.
long delta ///< This number is subtracted from the value of block blockAddr.
) {
return MIFARE_TwoStepHelper(PICC_CMD_MF_DECREMENT, blockAddr, delta);
} // End MIFARE_Decrement()
/**
* MIFARE Increment adds the delta to the value of the addressed block, and stores the result in a volatile memory.
* For MIFARE Classic only. The sector containing the block must be authenticated before calling this function.
* Only for blocks in "value block" mode, ie with access bits [C1 C2 C3] = [110] or [001].
* Use MIFARE_Transfer() to store the result in a block.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Increment( byte blockAddr, ///< The block (0-0xff) number.
long delta ///< This number is added to the value of block blockAddr.
) {
return MIFARE_TwoStepHelper(PICC_CMD_MF_INCREMENT, blockAddr, delta);
} // End MIFARE_Increment()
/**
* MIFARE Restore copies the value of the addressed block into a volatile memory.
* For MIFARE Classic only. The sector containing the block must be authenticated before calling this function.
* Only for blocks in "value block" mode, ie with access bits [C1 C2 C3] = [110] or [001].
* Use MIFARE_Transfer() to store the result in a block.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Restore( byte blockAddr ///< The block (0-0xff) number.
) {
// The datasheet describes Restore as a two step operation, but does not explain what data to transfer in step 2.
// Doing only a single step does not work, so I chose to transfer 0L in step two.
return MIFARE_TwoStepHelper(PICC_CMD_MF_RESTORE, blockAddr, 0L);
} // End MIFARE_Restore()
/**
* Helper function for the two-step MIFARE Classic protocol operations Decrement, Increment and Restore.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_TwoStepHelper( byte command, ///< The command to use
byte blockAddr, ///< The block (0-0xff) number.
long data ///< The data to transfer in step 2
) {
byte result;
byte cmdBuffer[2]; // We only need room for 2 bytes.
// Step 1: Tell the PICC the command and block address
cmdBuffer[0] = command;
cmdBuffer[1] = blockAddr;
result = PCD_MIFARE_Transceive( cmdBuffer, 2); // Adds CRC_A and checks that the response is MF_ACK.
if (result != STATUS_OK) {
return result;
}
// Step 2: Transfer the data
result = PCD_MIFARE_Transceive( (byte *)&data, 4, true); // Adds CRC_A and accept timeout as success.
if (result != STATUS_OK) {
return result;
}
return STATUS_OK;
} // End MIFARE_TwoStepHelper()
/**
* MIFARE Transfer writes the value stored in the volatile memory into one MIFARE Classic block.
* For MIFARE Classic only. The sector containing the block must be authenticated before calling this function.
* Only for blocks in "value block" mode, ie with access bits [C1 C2 C3] = [110] or [001].
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_Transfer( byte blockAddr ///< The block (0-0xff) number.
) {
byte result;
byte cmdBuffer[2]; // We only need room for 2 bytes.
// Tell the PICC we want to transfer the result into block blockAddr.
cmdBuffer[0] = PICC_CMD_MF_TRANSFER;
cmdBuffer[1] = blockAddr;
result = PCD_MIFARE_Transceive( cmdBuffer, 2); // Adds CRC_A and checks that the response is MF_ACK.
if (result != STATUS_OK) {
return result;
}
return STATUS_OK;
} // End MIFARE_Transfer()
/**
* Helper routine to read the current value from a Value Block.
*
* Only for MIFARE Classic and only for blocks in "value block" mode, that
* is: with access bits [C1 C2 C3] = [110] or [001]. The sector containing
* the block must be authenticated before calling this function.
*
* @param[in] blockAddr The block (0x00-0xff) number.
* @param[out] value Current value of the Value Block.
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_GetValue(byte blockAddr, long *value) {
byte status;
byte buffer[18];
byte size = sizeof(buffer);
// Read the block
status = MIFARE_Read(blockAddr, buffer, &size);
if (status == STATUS_OK) {
// Extract the value
*value = (long(buffer[3])<<24) | (long(buffer[2])<<16) | (long(buffer[1])<<8) | long(buffer[0]);
}
return status;
} // End MIFARE_GetValue()
/**
* Helper routine to write a specific value into a Value Block.
*
* Only for MIFARE Classic and only for blocks in "value block" mode, that
* is: with access bits [C1 C2 C3] = [110] or [001]. The sector containing
* the block must be authenticated before calling this function.
*
* @param[in] blockAddr The block (0x00-0xff) number.
* @param[in] value New value of the Value Block.
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::MIFARE_SetValue(byte blockAddr, long value) {
byte buffer[18];
// Translate the long into 4 bytes; repeated 2x in value block
buffer[0] = buffer[ 8] = (value & 0xFF);
buffer[1] = buffer[ 9] = (value & 0xFF00) >> 8;
buffer[2] = buffer[10] = (value & 0xFF0000) >> 16;
buffer[3] = buffer[11] = (value & 0xFF000000) >> 24;
// Inverse 4 bytes also found in value block
buffer[4] = ~buffer[0];
buffer[5] = ~buffer[1];
buffer[6] = ~buffer[2];
buffer[7] = ~buffer[3];
// Address 2x with inverse address 2x
buffer[12] = buffer[14] = blockAddr;
buffer[13] = buffer[15] = ~blockAddr;
// Write the whole data block
return MIFARE_Write(blockAddr, buffer, 16);
} // End MIFARE_SetValue()
/////////////////////////////////////////////////////////////////////////////////////
// Support functions
/////////////////////////////////////////////////////////////////////////////////////
/**
* Wrapper for MIFARE protocol communication.
* Adds CRC_A, executes the Transceive command and checks that the response is MF_ACK or a timeout.
*
* @return STATUS_OK on success, STATUS_??? otherwise.
*/
byte MFRC522::PCD_MIFARE_Transceive( byte *sendData, ///< Pointer to the data to transfer to the FIFO. Do NOT include the CRC_A.
byte sendLen, ///< Number of bytes in sendData.
bool acceptTimeout ///< True => A timeout is also success
) {
byte result;
byte cmdBuffer[18]; // We need room for 16 bytes data and 2 bytes CRC_A.
// Sanity check
if (sendData == NULL || sendLen > 16) {
return STATUS_INVALID;
}
// Copy sendData[] to cmdBuffer[] and add CRC_A
memcpy(cmdBuffer, sendData, sendLen);
result = PCD_CalculateCRC(cmdBuffer, sendLen, &cmdBuffer[sendLen]);
if (result != STATUS_OK) {
return result;
}
sendLen += 2;
// Transceive the data, store the reply in cmdBuffer[]
byte waitIRq = 0x30; // RxIRq and IdleIRq
byte cmdBufferSize = sizeof(cmdBuffer);
byte validBits = 0;
result = PCD_CommunicateWithPICC(PCD_Transceive, waitIRq, cmdBuffer, sendLen, cmdBuffer, &cmdBufferSize, &validBits);
if (acceptTimeout && result == STATUS_TIMEOUT) {
return STATUS_OK;
}
if (result != STATUS_OK) {
return result;
}
// The PICC must reply with a 4 bit ACK
if (cmdBufferSize != 1 || validBits != 4) {
return STATUS_ERROR;
}
if (cmdBuffer[0] != MF_ACK) {
return STATUS_MIFARE_NACK;
}
return STATUS_OK;
} // End PCD_MIFARE_Transceive()
/**
* Returns a __FlashStringHelper pointer to a status code name.
*
* @return const __FlashStringHelper *
*/
const __FlashStringHelper *MFRC522::GetStatusCodeName(byte code ///< One of the StatusCode enums.
) {
switch (code) {
case STATUS_OK: return F("Success."); break;
case STATUS_ERROR: return F("Error in communication."); break;
case STATUS_COLLISION: return F("Collission detected."); break;
case STATUS_TIMEOUT: return F("Timeout in communication."); break;
case STATUS_NO_ROOM: return F("A buffer is not big enough."); break;
case STATUS_INTERNAL_ERROR: return F("Internal error in the code. Should not happen."); break;
case STATUS_INVALID: return F("Invalid argument."); break;
case STATUS_CRC_WRONG: return F("The CRC_A does not match."); break;
case STATUS_MIFARE_NACK: return F("A MIFARE PICC responded with NAK."); break;
default: return F("Unknown error"); break;
}
} // End GetStatusCodeName()
/**
* Translates the SAK (Select Acknowledge) to a PICC type.
*
* @return PICC_Type
*/
byte MFRC522::PICC_GetType(byte sak ///< The SAK byte returned from PICC_Select().
) {
if (sak & 0x04) { // UID not complete
return PICC_TYPE_NOT_COMPLETE;
}
switch (sak) {
case 0x09: return PICC_TYPE_MIFARE_MINI; break;
case 0x08: return PICC_TYPE_MIFARE_1K; break;
case 0x18: return PICC_TYPE_MIFARE_4K; break;
case 0x00: return PICC_TYPE_MIFARE_UL; break;
case 0x10:
case 0x11: return PICC_TYPE_MIFARE_PLUS; break;
case 0x01: return PICC_TYPE_TNP3XXX; break;
default: break;
}
if (sak & 0x20) {
return PICC_TYPE_ISO_14443_4;
}
if (sak & 0x40) {
return PICC_TYPE_ISO_18092;
}
return PICC_TYPE_UNKNOWN;
} // End PICC_GetType()
/**
* Returns a __FlashStringHelper pointer to the PICC type name.
*
* @return const __FlashStringHelper *
*/
const __FlashStringHelper *MFRC522::PICC_GetTypeName(byte piccType ///< One of the PICC_Type enums.
) {
switch (piccType) {
case PICC_TYPE_ISO_14443_4: return F("PICC compliant with ISO/IEC 14443-4"); break;
case PICC_TYPE_ISO_18092: return F("PICC compliant with ISO/IEC 18092 (NFC)");break;
case PICC_TYPE_MIFARE_MINI: return F("MIFARE Mini, 320 bytes"); break;
case PICC_TYPE_MIFARE_1K: return F("MIFARE 1KB"); break;
case PICC_TYPE_MIFARE_4K: return F("MIFARE 4KB"); break;
case PICC_TYPE_MIFARE_UL: return F("MIFARE Ultralight or Ultralight C"); break;
case PICC_TYPE_MIFARE_PLUS: return F("MIFARE Plus"); break;
case PICC_TYPE_TNP3XXX: return F("MIFARE TNP3XXX"); break;
case PICC_TYPE_NOT_COMPLETE: return F("SAK indicates UID is not complete."); break;
case PICC_TYPE_UNKNOWN:
default: return F("Unknown type"); break;
}
} // End PICC_GetTypeName()
/**
* Dumps debug info about the selected PICC to Serial.
* On success the PICC is halted after dumping the data.
* For MIFARE Classic the factory default key of 0xFFFFFFFFFFFF is tried.
*/
void MFRC522::PICC_DumpToSerial(Uid *uid ///< Pointer to Uid struct returned from a successful PICC_Select().
) {
MIFARE_Key key;
// UID
Serial.print(F("Card UID:"));
for (byte i = 0; i < uid->size; i++) {
if(uid->uidByte[i] < 0x10)
Serial.print(F(" 0"));
else
Serial.print(F(" "));
Serial.print(uid->uidByte[i], HEX);
}
Serial.println();
// PICC type
byte piccType = PICC_GetType(uid->sak);
Serial.print(F("PICC type: "));
Serial.println(PICC_GetTypeName(piccType));
// Dump contents
switch (piccType) {
case PICC_TYPE_MIFARE_MINI:
case PICC_TYPE_MIFARE_1K:
case PICC_TYPE_MIFARE_4K:
// All keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
for (byte i = 0; i < 6; i++) {
key.keyByte[i] = 0xFF;
}
PICC_DumpMifareClassicToSerial(uid, piccType, &key);
break;
case PICC_TYPE_MIFARE_UL:
PICC_DumpMifareUltralightToSerial();
break;
case PICC_TYPE_ISO_14443_4:
case PICC_TYPE_ISO_18092:
case PICC_TYPE_MIFARE_PLUS:
case PICC_TYPE_TNP3XXX:
Serial.println(F("Dumping memory contents not implemented for that PICC type."));
break;
case PICC_TYPE_UNKNOWN:
case PICC_TYPE_NOT_COMPLETE:
default:
break; // No memory dump here
}
Serial.println();
PICC_HaltA(); // Already done if it was a MIFARE Classic PICC.
} // End PICC_DumpToSerial()
/**
* Dumps memory contents of a MIFARE Classic PICC.
* On success the PICC is halted after dumping the data.
*/
void MFRC522::PICC_DumpMifareClassicToSerial( Uid *uid, ///< Pointer to Uid struct returned from a successful PICC_Select().
byte piccType, ///< One of the PICC_Type enums.
MIFARE_Key *key ///< Key A used for all sectors.
) {
byte no_of_sectors = 0;
switch (piccType) {
case PICC_TYPE_MIFARE_MINI:
// Has 5 sectors * 4 blocks/sector * 16 bytes/block = 320 bytes.
no_of_sectors = 5;
break;
case PICC_TYPE_MIFARE_1K:
// Has 16 sectors * 4 blocks/sector * 16 bytes/block = 1024 bytes.
no_of_sectors = 16;
break;
case PICC_TYPE_MIFARE_4K:
// Has (32 sectors * 4 blocks/sector + 8 sectors * 16 blocks/sector) * 16 bytes/block = 4096 bytes.
no_of_sectors = 40;
break;
default: // Should not happen. Ignore.
break;
}
// Dump sectors, highest address first.
if (no_of_sectors) {
Serial.println(F("Sector Block 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 AccessBits"));
for (int8_t i = no_of_sectors - 1; i >= 0; i--) {
PICC_DumpMifareClassicSectorToSerial(uid, key, i);
}
}
PICC_HaltA(); // Halt the PICC before stopping the encrypted session.
PCD_StopCrypto1();
} // End PICC_DumpMifareClassicToSerial()
/**
* Dumps memory contents of a sector of a MIFARE Classic PICC.
* Uses PCD_Authenticate(), MIFARE_Read() and PCD_StopCrypto1.
* Always uses PICC_CMD_MF_AUTH_KEY_A because only Key A can always read the sector trailer access bits.
*/
void MFRC522::PICC_DumpMifareClassicSectorToSerial(Uid *uid, ///< Pointer to Uid struct returned from a successful PICC_Select().
MIFARE_Key *key, ///< Key A for the sector.
byte sector ///< The sector to dump, 0..39.
) {
byte status;
byte firstBlock; // Address of lowest address to dump actually last block dumped)
byte no_of_blocks; // Number of blocks in sector
bool isSectorTrailer; // Set to true while handling the "last" (ie highest address) in the sector.
// The access bits are stored in a peculiar fashion.
// There are four groups:
// g[3] Access bits for the sector trailer, block 3 (for sectors 0-31) or block 15 (for sectors 32-39)
// g[2] Access bits for block 2 (for sectors 0-31) or blocks 10-14 (for sectors 32-39)
// g[1] Access bits for block 1 (for sectors 0-31) or blocks 5-9 (for sectors 32-39)
// g[0] Access bits for block 0 (for sectors 0-31) or blocks 0-4 (for sectors 32-39)
// Each group has access bits [C1 C2 C3]. In this code C1 is MSB and C3 is LSB.
// The four CX bits are stored together in a nible cx and an inverted nible cx_.
byte c1, c2, c3; // Nibbles
byte c1_, c2_, c3_; // Inverted nibbles
bool invertedError; // True if one of the inverted nibbles did not match
byte g[4]; // Access bits for each of the four groups.
byte group; // 0-3 - active group for access bits
bool firstInGroup; // True for the first block dumped in the group
// Determine position and size of sector.
if (sector < 32) { // Sectors 0..31 has 4 blocks each
no_of_blocks = 4;
firstBlock = sector * no_of_blocks;
}
else if (sector < 40) { // Sectors 32-39 has 16 blocks each
no_of_blocks = 16;
firstBlock = 128 + (sector - 32) * no_of_blocks;
}
else { // Illegal input, no MIFARE Classic PICC has more than 40 sectors.
return;
}
// Dump blocks, highest address first.
byte byteCount;
byte buffer[18];
byte blockAddr;
isSectorTrailer = true;
for (int8_t blockOffset = no_of_blocks - 1; blockOffset >= 0; blockOffset--) {
blockAddr = firstBlock + blockOffset;
// Sector number - only on first line
if (isSectorTrailer) {
if(sector < 10)
Serial.print(F(" ")); // Pad with spaces
else
Serial.print(F(" ")); // Pad with spaces
Serial.print(sector);
Serial.print(F(" "));
}
else {
Serial.print(F(" "));
}
// Block number
if(blockAddr < 10)
Serial.print(F(" ")); // Pad with spaces
else {
if(blockAddr < 100)
Serial.print(F(" ")); // Pad with spaces
else
Serial.print(F(" ")); // Pad with spaces
}
Serial.print(blockAddr);
Serial.print(F(" "));
// Establish encrypted communications before reading the first block
if (isSectorTrailer) {
status = PCD_Authenticate(PICC_CMD_MF_AUTH_KEY_A, firstBlock, key, uid);
if (status != STATUS_OK) {
Serial.print(F("PCD_Authenticate() failed: "));
Serial.println(GetStatusCodeName(status));
return;
}
}
// Read block
byteCount = sizeof(buffer);
status = MIFARE_Read(blockAddr, buffer, &byteCount);
if (status != STATUS_OK) {
Serial.print(F("MIFARE_Read() failed: "));
Serial.println(GetStatusCodeName(status));
continue;
}
// Dump data
for (byte index = 0; index < 16; index++) {
if(buffer[index] < 0x10)
Serial.print(F(" 0"));
else
Serial.print(F(" "));
Serial.print(buffer[index], HEX);
if ((index % 4) == 3) {
Serial.print(F(" "));
}
}
// Parse sector trailer data
if (isSectorTrailer) {
c1 = buffer[7] >> 4;
c2 = buffer[8] & 0xF;
c3 = buffer[8] >> 4;
c1_ = buffer[6] & 0xF;
c2_ = buffer[6] >> 4;
c3_ = buffer[7] & 0xF;
invertedError = (c1 != (~c1_ & 0xF)) || (c2 != (~c2_ & 0xF)) || (c3 != (~c3_ & 0xF));
g[0] = ((c1 & 1) << 2) | ((c2 & 1) << 1) | ((c3 & 1) << 0);
g[1] = ((c1 & 2) << 1) | ((c2 & 2) << 0) | ((c3 & 2) >> 1);
g[2] = ((c1 & 4) << 0) | ((c2 & 4) >> 1) | ((c3 & 4) >> 2);
g[3] = ((c1 & 8) >> 1) | ((c2 & 8) >> 2) | ((c3 & 8) >> 3);
isSectorTrailer = false;
}
// Which access group is this block in?
if (no_of_blocks == 4) {
group = blockOffset;
firstInGroup = true;
}
else {
group = blockOffset / 5;
firstInGroup = (group == 3) || (group != (blockOffset + 1) / 5);
}
if (firstInGroup) {
// Print access bits
Serial.print(F(" [ "));
Serial.print((g[group] >> 2) & 1, DEC); Serial.print(F(" "));
Serial.print((g[group] >> 1) & 1, DEC); Serial.print(F(" "));
Serial.print((g[group] >> 0) & 1, DEC);
Serial.print(F(" ] "));
if (invertedError) {
Serial.print(F(" Inverted access bits did not match! "));
}
}
if (group != 3 && (g[group] == 1 || g[group] == 6)) { // Not a sector trailer, a value block
long value = (long(buffer[3])<<24) | (long(buffer[2])<<16) | (long(buffer[1])<<8) | long(buffer[0]);
Serial.print(F(" Value=0x")); Serial.print(value, HEX);
Serial.print(F(" Adr=0x")); Serial.print(buffer[12], HEX);
}
Serial.println();
}
return;
} // End PICC_DumpMifareClassicSectorToSerial()
/**
* Dumps memory contents of a MIFARE Ultralight PICC.
*/
void MFRC522::PICC_DumpMifareUltralightToSerial() {
byte status;
byte byteCount;
byte buffer[18];
byte i;
Serial.println(F("Page 0 1 2 3"));
// Try the mpages of the original Ultralight. Ultralight C has more pages.
for (byte page = 0; page < 16; page +=4) { // Read returns data for 4 pages at a time.
// Read pages
byteCount = sizeof(buffer);
status = MIFARE_Read(page, buffer, &byteCount);
if (status != STATUS_OK) {
Serial.print(F("MIFARE_Read() failed: "));
Serial.println(GetStatusCodeName(status));
break;
}
// Dump data
for (byte offset = 0; offset < 4; offset++) {
i = page + offset;
if(i < 10)
Serial.print(F(" ")); // Pad with spaces
else
Serial.print(F(" ")); // Pad with spaces
Serial.print(i);
Serial.print(F(" "));
for (byte index = 0; index < 4; index++) {
i = 4 * offset + index;
if(buffer[i] < 0x10)
Serial.print(F(" 0"));
else
Serial.print(F(" "));
Serial.print(buffer[i], HEX);
}
Serial.println();
}
}
} // End PICC_DumpMifareUltralightToSerial()
/**
* Calculates the bit pattern needed for the specified access bits. In the [C1 C2 C3] tupples C1 is MSB (=4) and C3 is LSB (=1).
*/
void MFRC522::MIFARE_SetAccessBits( byte *accessBitBuffer, ///< Pointer to byte 6, 7 and 8 in the sector trailer. Bytes [0..2] will be set.
byte g0, ///< Access bits [C1 C2 C3] for block 0 (for sectors 0-31) or blocks 0-4 (for sectors 32-39)
byte g1, ///< Access bits C1 C2 C3] for block 1 (for sectors 0-31) or blocks 5-9 (for sectors 32-39)
byte g2, ///< Access bits C1 C2 C3] for block 2 (for sectors 0-31) or blocks 10-14 (for sectors 32-39)
byte g3 ///< Access bits C1 C2 C3] for the sector trailer, block 3 (for sectors 0-31) or block 15 (for sectors 32-39)
) {
byte c1 = ((g3 & 4) << 1) | ((g2 & 4) << 0) | ((g1 & 4) >> 1) | ((g0 & 4) >> 2);
byte c2 = ((g3 & 2) << 2) | ((g2 & 2) << 1) | ((g1 & 2) << 0) | ((g0 & 2) >> 1);
byte c3 = ((g3 & 1) << 3) | ((g2 & 1) << 2) | ((g1 & 1) << 1) | ((g0 & 1) << 0);
accessBitBuffer[0] = (~c2 & 0xF) << 4 | (~c1 & 0xF);
accessBitBuffer[1] = c1 << 4 | (~c3 & 0xF);
accessBitBuffer[2] = c3 << 4 | c2;
} // End MIFARE_SetAccessBits()
/**
* Performs the "magic sequence" needed to get Chinese UID changeable
* Mifare cards to allow writing to sector 0, where the card UID is stored.
*
* Note that you do not need to have selected the card through REQA or WUPA,
* this sequence works immediately when the card is in the reader vicinity.
* This means you can use this method even on "bricked" cards that your reader does
* not recognise anymore (see MFRC522::MIFARE_UnbrickUidSector).
*
* Of course with non-bricked devices, you're free to select them before calling this function.
*/
bool MFRC522::MIFARE_OpenUidBackdoor(bool logErrors) {
// Magic sequence:
// > 50 00 57 CD (HALT + CRC)
// > 40 (7 bits only)
// < A (4 bits only)
// > 43
// < A (4 bits only)
// Then you can write to sector 0 without authenticating
PICC_HaltA(); // 50 00 57 CD
byte cmd = 0x40;
byte validBits = 7; /* Our command is only 7 bits. After receiving card response,
this will contain amount of valid response bits. */
byte response[32]; // Card's response is written here
byte received;
byte status = PCD_TransceiveData(&cmd, (byte)1, response, &received, &validBits, (byte)0, false); // 40
if(status != STATUS_OK) {
if(logErrors) {
Serial.println(F("Card did not respond to 0x40 after HALT command. Are you sure it is a UID changeable one?"));
Serial.print(F("Error name: "));
Serial.println(GetStatusCodeName(status));
}
return false;
}
if (received != 1 || response[0] != 0x0A) {
if (logErrors) {
Serial.print(F("Got bad response on backdoor 0x40 command: "));
Serial.print(response[0], HEX);
Serial.print(F(" ("));
Serial.print(validBits);
Serial.print(F(" valid bits)\r\n"));
}
return false;
}
cmd = 0x43;
validBits = 8;
status = PCD_TransceiveData(&cmd, (byte)1, response, &received, &validBits, (byte)0, false); // 43
if(status != STATUS_OK) {
if(logErrors) {
Serial.println(F("Error in communication at command 0x43, after successfully executing 0x40"));
Serial.print(F("Error name: "));
Serial.println(GetStatusCodeName(status));
}
return false;
}
if (received != 1 || response[0] != 0x0A) {
if (logErrors) {
Serial.print(F("Got bad response on backdoor 0x43 command: "));
Serial.print(response[0], HEX);
Serial.print(F(" ("));
Serial.print(validBits);
Serial.print(F(" valid bits)\r\n"));
}
return false;
}
// You can now write to sector 0 without authenticating!
return true;
} // End MIFARE_OpenUidBackdoor()
/**
* Reads entire block 0, including all manufacturer data, and overwrites
* that block with the new UID, a freshly calculated BCC, and the original
* manufacturer data.
*
* It assumes a default KEY A of 0xFFFFFFFFFFFF.
* Make sure to have selected the card before this function is called.
*/
bool MFRC522::MIFARE_SetUid(byte *newUid, byte uidSize, bool logErrors) {
// UID + BCC byte can not be larger than 16 together
if (!newUid || !uidSize || uidSize > 15) {
if (logErrors) {
Serial.println(F("New UID buffer empty, size 0, or size > 15 given"));
}
return false;
}
// Authenticate for reading
MIFARE_Key key = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
byte status = PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, (byte)1, &key, &uid);
if (status != STATUS_OK) {
if (status == STATUS_TIMEOUT) {
// We get a read timeout if no card is selected yet, so let's select one
// Wake the card up again if sleeping
// byte atqa_answer[2];
// byte atqa_size = 2;
// PICC_WakeupA(atqa_answer, &atqa_size);
if (!PICC_IsNewCardPresent() || !PICC_ReadCardSerial()) {
Serial.println(F("No card was previously selected, and none are available. Failed to set UID."));
return false;
}
status = PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, (byte)1, &key, &uid);
if (status != STATUS_OK) {
// We tried, time to give up
if (logErrors) {
Serial.println(F("Failed to authenticate to card for reading, could not set UID: "));
Serial.println(GetStatusCodeName(status));
}
return false;
}
}
else {
if (logErrors) {
Serial.print(F("PCD_Authenticate() failed: "));
Serial.println(GetStatusCodeName(status));
}
return false;
}
}
// Read block 0
byte block0_buffer[18];
byte byteCount = sizeof(block0_buffer);
status = MIFARE_Read((byte)0, block0_buffer, &byteCount);
if (status != STATUS_OK) {
if (logErrors) {
Serial.print(F("MIFARE_Read() failed: "));
Serial.println(GetStatusCodeName(status));
Serial.println(F("Are you sure your KEY A for sector 0 is 0xFFFFFFFFFFFF?"));
}
return false;
}
// Write new UID to the data we just read, and calculate BCC byte
byte bcc = 0;
for (int i = 0; i < uidSize; i++) {
block0_buffer[i] = newUid[i];
bcc ^= newUid[i];
}
// Write BCC byte to buffer
block0_buffer[uidSize] = bcc;
// Stop encrypted traffic so we can send raw bytes
PCD_StopCrypto1();
// Activate UID backdoor
if (!MIFARE_OpenUidBackdoor(logErrors)) {
if (logErrors) {
Serial.println(F("Activating the UID backdoor failed."));
}
return false;
}
// Write modified block 0 back to card
status = MIFARE_Write((byte)0, block0_buffer, (byte)16);
if (status != STATUS_OK) {
if (logErrors) {
Serial.print(F("MIFARE_Write() failed: "));
Serial.println(GetStatusCodeName(status));
}
return false;
}
// Wake the card up again
byte atqa_answer[2];
byte atqa_size = 2;
PICC_WakeupA(atqa_answer, &atqa_size);
return true;
}
/**
* Resets entire sector 0 to zeroes, so the card can be read again by readers.
*/
bool MFRC522::MIFARE_UnbrickUidSector(bool logErrors) {
MIFARE_OpenUidBackdoor(logErrors);
byte block0_buffer[] = {0x01, 0x02, 0x03, 0x04, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
// Write modified block 0 back to card
byte status = MIFARE_Write((byte)0, block0_buffer, (byte)16);
if (status != STATUS_OK) {
if (logErrors) {
Serial.print(F("MIFARE_Write() failed: "));
Serial.println(GetStatusCodeName(status));
}
return false;
}
return true;
}
/////////////////////////////////////////////////////////////////////////////////////
// Convenience functions - does not add extra functionality
/////////////////////////////////////////////////////////////////////////////////////
/**
* Returns true if a PICC responds to PICC_CMD_REQA.
* Only "new" cards in state IDLE are invited. Sleeping cards in state HALT are ignored.
*
* @return bool
*/
bool MFRC522::PICC_IsNewCardPresent() {
byte bufferATQA[2];
byte bufferSize = sizeof(bufferATQA);
byte result = PICC_RequestA(bufferATQA, &bufferSize);
return (result == STATUS_OK || result == STATUS_COLLISION);
} // End PICC_IsNewCardPresent()
/**
* Simple wrapper around PICC_Select.
* Returns true if a UID could be read.
* Remember to call PICC_IsNewCardPresent(), PICC_RequestA() or PICC_WakeupA() first.
* The read UID is available in the class variable uid.
*
* @return bool
*/
bool MFRC522::PICC_ReadCardSerial() {
byte result = PICC_Select(&uid);
return (result == STATUS_OK);
} // End PICC_ReadCardSerial()
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