yotsaphat Lertsukon
5555
Revision 0:4f5ffc06a65b, committed 2017-12-11
- Comitter:
- 59340500048
- Date:
- Mon Dec 11 15:27:03 2017 +0000
- Commit message:
- eiei
Changed in this revision
| MFRC522.cpp | Show annotated file Show diff for this revision Revisions of this file |
| MFRC522.h | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MFRC522.cpp Mon Dec 11 15:27:03 2017 +0000
@@ -0,0 +1,1154 @@
+/*
+* MFRC522.cpp - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI W AND R BY COOQROBOT.
+* _Please_ see the comments in MFRC522.h - they give useful hints and background.
+* Released into the public domain.
+*/
+
+#include "MFRC522.h"
+
+static const char* const _TypeNamePICC[] =
+{
+ "Unknown type",
+ "PICC compliant with ISO/IEC 14443-4",
+ "PICC compliant with ISO/IEC 18092 (NFC)",
+ "MIFARE Mini, 320 bytes",
+ "MIFARE 1KB",
+ "MIFARE 4KB",
+ "MIFARE Ultralight or Ultralight C",
+ "MIFARE Plus",
+ "MIFARE TNP3XXX",
+
+ /* not complete UID */
+ "SAK indicates UID is not complete"
+};
+
+static const char* const _ErrorMessage[] =
+{
+ "Unknown error",
+ "Success",
+ "Error in communication",
+ "Collision detected",
+ "Timeout in communication",
+ "A buffer is not big enough",
+ "Internal error in the code, should not happen",
+ "Invalid argument",
+ "The CRC_A does not match",
+ "A MIFARE PICC responded with NAK"
+};
+
+#define MFRC522_MaxPICCs (sizeof(_TypeNamePICC)/sizeof(_TypeNamePICC[0]))
+#define MFRC522_MaxError (sizeof(_ErrorMessage)/sizeof(_ErrorMessage[0]))
+
+/////////////////////////////////////////////////////////////////////////////////////
+// Functions for setting up the driver
+/////////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Constructor.
+ * Prepares the output pins.
+ */
+MFRC522::MFRC522(PinName mosi,
+ PinName miso,
+ PinName sclk,
+ PinName cs,
+ PinName reset) : m_SPI(mosi, miso, sclk), m_CS(cs), m_RESET(reset)
+{
+ /* Configure SPI bus */
+ m_SPI.format(8, 0);
+ m_SPI.frequency(8000000);
+
+ /* Release SPI-CS pin */
+ m_CS = 1;
+
+ /* Release RESET pin */
+ m_RESET = 1;
+} // End constructor
+
+
+/**
+ * Destructor.
+ */
+MFRC522::~MFRC522()
+{
+
+}
+
+
+/////////////////////////////////////////////////////////////////////////////////////
+// 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(uint8_t reg, uint8_t value)
+{
+ m_CS = 0; /* Select SPI Chip MFRC522 */
+
+ // MSB == 0 is for writing. LSB is not used in address. Datasheet section 8.1.2.3.
+ (void) m_SPI.write(reg & 0x7E);
+ (void) m_SPI.write(value);
+
+ m_CS = 1; /* Release SPI Chip MFRC522 */
+} // 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(uint8_t reg, uint8_t count, uint8_t *values)
+{
+ m_CS = 0; /* Select SPI Chip MFRC522 */
+
+ // MSB == 0 is for writing. LSB is not used in address. Datasheet section 8.1.2.3.
+ (void) m_SPI.write(reg & 0x7E);
+ for (uint8_t index = 0; index < count; index++)
+ {
+ (void) m_SPI.write(values[index]);
+ }
+
+ m_CS = 1; /* Release SPI Chip MFRC522 */
+} // 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.
+ */
+uint8_t MFRC522::PCD_ReadRegister(uint8_t reg)
+{
+ uint8_t value;
+ m_CS = 0; /* Select SPI Chip MFRC522 */
+
+ // MSB == 1 is for reading. LSB is not used in address. Datasheet section 8.1.2.3.
+ (void) m_SPI.write(0x80 | reg);
+
+ // Read the value back. Send 0 to stop reading.
+ value = m_SPI.write(0);
+
+ m_CS = 1; /* Release SPI Chip MFRC522 */
+
+ 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(uint8_t reg, uint8_t count, uint8_t *values, uint8_t rxAlign)
+{
+ if (count == 0) { return; }
+
+ uint8_t address = 0x80 | reg; // MSB == 1 is for reading. LSB is not used in address. Datasheet section 8.1.2.3.
+ uint8_t index = 0; // Index in values array.
+
+ m_CS = 0; /* Select SPI Chip MFRC522 */
+ count--; // One read is performed outside of the loop
+ (void) m_SPI.write(address); // Tell MFRC522 which address we want to read
+
+ while (index < count)
+ {
+ if ((index == 0) && rxAlign) // Only update bit positions rxAlign..7 in values[0]
+ {
+ // Create bit mask for bit positions rxAlign..7
+ uint8_t mask = 0;
+ for (uint8_t i = rxAlign; i <= 7; i++)
+ {
+ mask |= (1 << i);
+ }
+
+ // Read value and tell that we want to read the same address again.
+ uint8_t value = m_SPI.write(address);
+
+ // Apply mask to both current value of values[0] and the new data in value.
+ values[0] = (values[index] & ~mask) | (value & mask);
+ }
+ else
+ {
+ // Read value and tell that we want to read the same address again.
+ values[index] = m_SPI.write(address);
+ }
+
+ index++;
+ }
+
+ values[index] = m_SPI.write(0); // Read the final byte. Send 0 to stop reading.
+
+ m_CS = 1; /* Release SPI Chip MFRC522 */
+} // End PCD_ReadRegister()
+
+/**
+ * Sets the bits given in mask in register reg.
+ */
+void MFRC522::PCD_SetRegisterBits(uint8_t reg, uint8_t mask)
+{
+ uint8_t 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_ClrRegisterBits(uint8_t reg, uint8_t mask)
+{
+ uint8_t 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.
+ */
+uint8_t MFRC522::PCD_CalculateCRC(uint8_t *data, uint8_t length, uint8_t *result)
+{
+ PCD_WriteRegister(CommandReg, PCD_Idle); // Stop any active command.
+ PCD_WriteRegister(DivIrqReg, 0x04); // Clear the CRCIRq interrupt request bit
+ PCD_SetRegisterBits(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 17.73us.
+ uint16_t i = 5000;
+ uint8_t 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;
+ }
+ }
+
+ // Stop calculating CRC for new content in the FIFO.
+ PCD_WriteRegister(CommandReg, PCD_Idle);
+
+ // 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()
+{
+ /* Reset MFRC522 */
+ m_RESET = 0;
+ wait_ms(10);
+ m_RESET = 1;
+
+ // Section 8.8.2 in the datasheet says the oscillator start-up time is the start up time of the crystal + 37,74us. Let us be generous: 50ms.
+ wait_ms(50);
+
+ // 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 25us.
+ 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_WriteRegister(RFCfgReg, (0x07<<4)); // Set Rx Gain to max
+
+ 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 + 37,74us. Let us be generous: 50ms.
+ wait_ms(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 disabled.
+ */
+void MFRC522::PCD_AntennaOn()
+{
+ uint8_t value = PCD_ReadRegister(TxControlReg);
+ if ((value & 0x03) != 0x03)
+ {
+ PCD_WriteRegister(TxControlReg, value | 0x03);
+ }
+} // End PCD_AntennaOn()
+
+/////////////////////////////////////////////////////////////////////////////////////
+// Functions for communicating with PICCs
+/////////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Executes the Transceive command.
+ * CRC validation can only be done if backData and backLen are specified.
+ */
+uint8_t MFRC522::PCD_TransceiveData(uint8_t *sendData,
+ uint8_t sendLen,
+ uint8_t *backData,
+ uint8_t *backLen,
+ uint8_t *validBits,
+ uint8_t rxAlign,
+ bool checkCRC)
+{
+ uint8_t 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 commend, waits for completion and transfers data back from the FIFO.
+ * CRC validation can only be done if backData and backLen are specified.
+ */
+uint8_t MFRC522::PCD_CommunicateWithPICC(uint8_t command,
+ uint8_t waitIRq,
+ uint8_t *sendData,
+ uint8_t sendLen,
+ uint8_t *backData,
+ uint8_t *backLen,
+ uint8_t *validBits,
+ uint8_t rxAlign,
+ bool checkCRC)
+{
+ uint8_t n, _validBits = 0;
+ uint32_t i;
+
+ // Prepare values for BitFramingReg
+ uint8_t txLastBits = validBits ? *validBits : 0;
+ uint8_t 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_SetRegisterBits(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_SetRegisterBits(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 17.86us.
+ 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.
+ uint8_t 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.
+ uint8_t 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.
+ */
+uint8_t MFRC522::PICC_RequestA(uint8_t *bufferATQA, uint8_t *bufferSize)
+{
+ 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.
+ */
+uint8_t MFRC522::PICC_WakeupA(uint8_t *bufferATQA, uint8_t *bufferSize)
+{
+ 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.
+ */
+uint8_t MFRC522::PICC_REQA_or_WUPA(uint8_t command, uint8_t *bufferATQA, uint8_t *bufferSize)
+{
+ uint8_t validBits;
+ uint8_t status;
+
+ if (bufferATQA == NULL || *bufferSize < 2)
+ { // The ATQA response is 2 bytes long.
+ return STATUS_NO_ROOM;
+ }
+
+ // ValuesAfterColl=1 => Bits received after collision are cleared.
+ PCD_ClrRegisterBits(CollReg, 0x80);
+
+ // For REQA and WUPA we need the short frame format
+ // - transmit only 7 bits of the last (and only) byte. TxLastBits = BitFramingReg[2..0]
+ validBits = 7;
+
+ 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.
+ */
+uint8_t MFRC522::PICC_Select(Uid *uid, uint8_t validBits)
+{
+ bool uidComplete;
+ bool selectDone;
+ bool useCascadeTag;
+ uint8_t cascadeLevel = 1;
+ uint8_t result;
+ uint8_t count;
+ uint8_t index;
+ uint8_t uidIndex; // The first index in uid->uidByte[] that is used in the current Cascade Level.
+ uint8_t currentLevelKnownBits; // The number of known UID bits in the current Cascade Level.
+ uint8_t buffer[9]; // The SELECT/ANTICOLLISION commands uses a 7 byte standard frame + 2 bytes CRC_A
+ uint8_t bufferUsed; // The number of bytes used in the buffer, ie the number of bytes to transfer to the FIFO.
+ uint8_t rxAlign; // Used in BitFramingReg. Defines the bit position for the first bit received.
+ uint8_t txLastBits; // Used in BitFramingReg. The number of valid bits in the last transmitted byte.
+ uint8_t *responseBuffer;
+ uint8_t 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
+ // ValuesAfterColl=1 => Bits received after collision are cleared.
+ PCD_ClrRegisterBits(CollReg, 0x80);
+
+ // 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?
+ if(validBits > (8 * uidIndex))
+ {
+ currentLevelKnownBits = validBits - (8 * uidIndex);
+ }
+ else
+ {
+ currentLevelKnownBits = 0;
+ }
+
+ // Copy the known bits from uid->uidByte[] to buffer[]
+ index = 2; // destination index in buffer[]
+ if (useCascadeTag)
+ {
+ buffer[index++] = PICC_CMD_CT;
+ }
+
+ uint8_t bytesToCopy = currentLevelKnownBits / 8 + (currentLevelKnownBits % 8 ? 1 : 0); // The number of bytes needed to represent the known bits for this level.
+ if (bytesToCopy)
+ {
+ // Max 4 bytes in each Cascade Level. Only 3 left if we use the Cascade Tag
+ uint8_t maxBytes = useCascadeTag ? 3 : 4;
+ 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("SELECT: currentLevelKnownBits="); Serial.println(currentLevelKnownBits, DEC);
+ buffer[1] = 0x70; // NVB - Number of Valid Bits: Seven whole bytes
+
+ // Calulate 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("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
+ }
+
+ uint8_t 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.
+ */
+uint8_t MFRC522::PICC_HaltA()
+{
+ uint8_t result;
+ uint8_t 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)
+ {
+ // 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)
+ {
+ result = STATUS_OK;
+ }
+ else if (result == STATUS_OK)
+ { // That is ironically NOT ok in this case ;-)
+ result = STATUS_ERROR;
+ }
+ }
+
+ return result;
+} // End PICC_HaltA()
+
+
+/////////////////////////////////////////////////////////////////////////////////////
+// Functions for communicating with MIFARE PICCs
+/////////////////////////////////////////////////////////////////////////////////////
+
+/*
+ * Executes the MFRC522 MFAuthent command.
+ */
+uint8_t MFRC522::PCD_Authenticate(uint8_t command, uint8_t blockAddr, MIFARE_Key *key, Uid *uid)
+{
+ uint8_t i, waitIRq = 0x10; // IdleIRq
+
+ // Build command buffer
+ uint8_t sendData[12];
+ sendData[0] = command;
+ sendData[1] = blockAddr;
+
+ for (i = 0; i < MF_KEY_SIZE; i++)
+ { // 6 key bytes
+ sendData[2+i] = key->keyByte[i];
+ }
+
+ for (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_ClrRegisterBits(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.
+ */
+uint8_t MFRC522::MIFARE_Read(uint8_t blockAddr, uint8_t *buffer, uint8_t *bufferSize)
+{
+ uint8_t result = STATUS_NO_ROOM;
+
+ // Sanity check
+ if ((buffer == NULL) || (*bufferSize < 18))
+ {
+ return result;
+ }
+
+ // 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.
+ */
+uint8_t MFRC522::MIFARE_Write(uint8_t blockAddr, uint8_t *buffer, uint8_t bufferSize)
+{
+ uint8_t 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.
+ uint8_t cmdBuffer[2];
+ cmdBuffer[0] = PICC_CMD_MF_WRITE;
+ cmdBuffer[1] = blockAddr;
+ // Adds CRC_A and checks that the response is MF_ACK.
+ result = PCD_MIFARE_Transceive(cmdBuffer, 2);
+ if (result != STATUS_OK)
+ {
+ return result;
+ }
+
+ // Step 2: Transfer the data
+ // Adds CRC_A and checks that the response is MF_ACK.
+ result = PCD_MIFARE_Transceive(buffer, bufferSize);
+ if (result != STATUS_OK)
+ {
+ return result;
+ }
+
+ return STATUS_OK;
+} // End MIFARE_Write()
+
+/*
+ * Writes a 4 byte page to the active MIFARE Ultralight PICC.
+ */
+uint8_t MFRC522::MIFARE_UltralightWrite(uint8_t page, uint8_t *buffer, uint8_t bufferSize)
+{
+ uint8_t result;
+
+ // Sanity check
+ if (buffer == NULL || bufferSize < 4)
+ {
+ return STATUS_INVALID;
+ }
+
+ // Build commmand buffer
+ uint8_t 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.
+ */
+uint8_t MFRC522::MIFARE_Decrement(uint8_t blockAddr, uint32_t delta)
+{
+ 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.
+ */
+uint8_t MFRC522::MIFARE_Increment(uint8_t blockAddr, uint32_t delta)
+{
+ 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.
+ */
+uint8_t MFRC522::MIFARE_Restore(uint8_t blockAddr)
+{
+ // 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.
+ */
+uint8_t MFRC522::MIFARE_TwoStepHelper(uint8_t command, uint8_t blockAddr, uint32_t data)
+{
+ uint8_t result;
+ uint8_t 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;
+
+ // Adds CRC_A and checks that the response is MF_ACK.
+ result = PCD_MIFARE_Transceive(cmdBuffer, 2);
+ if (result != STATUS_OK)
+ {
+ return result;
+ }
+
+ // Step 2: Transfer the data
+ // Adds CRC_A and accept timeout as success.
+ result = PCD_MIFARE_Transceive((uint8_t *) &data, 4, true);
+ 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.
+ */
+uint8_t MFRC522::MIFARE_Transfer(uint8_t blockAddr)
+{
+ uint8_t 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;
+
+ // Adds CRC_A and checks that the response is MF_ACK.
+ return PCD_MIFARE_Transceive(cmdBuffer, 2);
+} // End MIFARE_Transfer()
+
+
+/////////////////////////////////////////////////////////////////////////////////////
+// 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.
+ */
+uint8_t MFRC522::PCD_MIFARE_Transceive(uint8_t *sendData, uint8_t sendLen, bool acceptTimeout)
+{
+ uint8_t result;
+ uint8_t 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[]
+ uint8_t waitIRq = 0x30; // RxIRq and IdleIRq
+ uint8_t cmdBufferSize = sizeof(cmdBuffer);
+ uint8_t 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()
+
+
+/*
+ * Translates the SAK (Select Acknowledge) to a PICC type.
+ */
+uint8_t MFRC522::PICC_GetType(uint8_t sak)
+{
+ uint8_t retType = PICC_TYPE_UNKNOWN;
+
+ if (sak & 0x04)
+ { // UID not complete
+ retType = PICC_TYPE_NOT_COMPLETE;
+ }
+ else
+ {
+ switch (sak)
+ {
+ case 0x09: retType = PICC_TYPE_MIFARE_MINI; break;
+ case 0x08: retType = PICC_TYPE_MIFARE_1K; break;
+ case 0x18: retType = PICC_TYPE_MIFARE_4K; break;
+ case 0x00: retType = PICC_TYPE_MIFARE_UL; break;
+ case 0x10:
+ case 0x11: retType = PICC_TYPE_MIFARE_PLUS; break;
+ case 0x01: retType = PICC_TYPE_TNP3XXX; break;
+ default:
+ if (sak & 0x20)
+ {
+ retType = PICC_TYPE_ISO_14443_4;
+ }
+ else if (sak & 0x40)
+ {
+ retType = PICC_TYPE_ISO_18092;
+ }
+ break;
+ }
+ }
+
+ return (retType);
+} // End PICC_GetType()
+
+/*
+ * Returns a string pointer to the PICC type name.
+ */
+char* MFRC522::PICC_GetTypeName(uint8_t piccType)
+{
+ if(piccType == PICC_TYPE_NOT_COMPLETE)
+ {
+ piccType = MFRC522_MaxPICCs - 1;
+ }
+
+ return((char *) _TypeNamePICC[piccType]);
+} // End PICC_GetTypeName()
+
+/*
+ * Returns a string pointer to a status code name.
+ */
+char* MFRC522::GetStatusCodeName(uint8_t code)
+{
+ return((char *) _ErrorMessage[code]);
+} // End GetStatusCodeName()
+
+/*
+ * 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(uint8_t *accessBitBuffer,
+ uint8_t g0,
+ uint8_t g1,
+ uint8_t g2,
+ uint8_t g3)
+{
+ uint8_t c1 = ((g3 & 4) << 1) | ((g2 & 4) << 0) | ((g1 & 4) >> 1) | ((g0 & 4) >> 2);
+ uint8_t c2 = ((g3 & 2) << 2) | ((g2 & 2) << 1) | ((g1 & 2) << 0) | ((g0 & 2) >> 1);
+ uint8_t 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()
+
+/////////////////////////////////////////////////////////////////////////////////////
+// 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.
+ */
+bool MFRC522::PICC_IsNewCardPresent(void)
+{
+ uint8_t bufferATQA[2];
+ uint8_t bufferSize = sizeof(bufferATQA);
+ uint8_t result = PICC_RequestA(bufferATQA, &bufferSize);
+ return ((result == STATUS_OK) || (result == STATUS_COLLISION));
+} // End PICC_IsNewCardPresent()
+
+/*
+ * Simple wrapper around PICC_Select.
+ */
+bool MFRC522::PICC_ReadCardSerial(void)
+{
+ uint8_t result = PICC_Select(&uid);
+ return (result == STATUS_OK);
+} // End PICC_ReadCardSerial()
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MFRC522.h Mon Dec 11 15:27:03 2017 +0000
@@ -0,0 +1,786 @@
+/**
+ * MFRC522.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.
+ * Rewritten by Soren Thing Andersen (access.thing.dk), fall of 2013 (Translation to English, refactored, comments, anti collision, cascade levels.)
+ * Ported to mbed by Martin Olejar, Dec, 2013
+ *
+ * Please read this file for an overview and then MFRC522.cpp for comments on the specific functions.
+ * Search for "mf-rc522" on ebay.com to purchase the MF-RC522 board.
+ *
+ * There are three hardware components involved:
+ * 1) The micro controller: An Arduino
+ * 2) The PCD (short for Proximity Coupling Device): NXP MFRC522 Contactless Reader IC
+ * 3) The PICC (short for Proximity Integrated Circuit Card): A card or tag using the ISO 14443A interface, eg Mifare or NTAG203.
+ *
+ * The microcontroller and card reader uses SPI for communication.
+ * The protocol is described in the MFRC522 datasheet: http://www.nxp.com/documents/data_sheet/MFRC522.pdf
+ *
+ * The card reader and the tags communicate using a 13.56MHz electromagnetic field.
+ * The protocol is defined in ISO/IEC 14443-3 Identification cards -- Contactless integrated circuit cards -- Proximity cards -- Part 3: Initialization and anticollision".
+ * A free version of the final draft can be found at http://wg8.de/wg8n1496_17n3613_Ballot_FCD14443-3.pdf
+ * Details are found in chapter 6, Type A: Initialization and anticollision.
+ *
+ * If only the PICC UID is wanted, the above documents has all the needed information.
+ * To read and write from MIFARE PICCs, the MIFARE protocol is used after the PICC has been selected.
+ * The MIFARE Classic chips and protocol is described in the datasheets:
+ * 1K: http://www.nxp.com/documents/data_sheet/MF1S503x.pdf
+ * 4K: http://www.nxp.com/documents/data_sheet/MF1S703x.pdf
+ * Mini: http://www.idcardmarket.com/download/mifare_S20_datasheet.pdf
+ * The MIFARE Ultralight chip and protocol is described in the datasheets:
+ * Ultralight: http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf
+ * Ultralight C: http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf
+ *
+ * MIFARE Classic 1K (MF1S503x):
+ * Has 16 sectors * 4 blocks/sector * 16 bytes/block = 1024 bytes.
+ * The blocks are numbered 0-63.
+ * Block 3 in each sector is the Sector Trailer. See http://www.nxp.com/documents/data_sheet/MF1S503x.pdf sections 8.6 and 8.7:
+ * Bytes 0-5: Key A
+ * Bytes 6-8: Access Bits
+ * Bytes 9: User data
+ * Bytes 10-15: Key B (or user data)
+ * Block 0 is read only manufacturer data.
+ * To access a block, an authentication using a key from the block's sector must be performed first.
+ * Example: To read from block 10, first authenticate using a key from sector 3 (blocks 8-11).
+ * All keys are set to FFFFFFFFFFFFh at chip delivery.
+ * Warning: Please read section 8.7 "Memory Access". It includes this text: if the PICC detects a format violation the whole sector is irreversibly blocked.
+ * To use a block in "value block" mode (for Increment/Decrement operations) you need to change the sector trailer. Use PICC_SetAccessBits() to calculate the bit patterns.
+ * MIFARE Classic 4K (MF1S703x):
+ * Has (32 sectors * 4 blocks/sector + 8 sectors * 16 blocks/sector) * 16 bytes/block = 4096 bytes.
+ * The blocks are numbered 0-255.
+ * The last block in each sector is the Sector Trailer like above.
+ * MIFARE Classic Mini (MF1 IC S20):
+ * Has 5 sectors * 4 blocks/sector * 16 bytes/block = 320 bytes.
+ * The blocks are numbered 0-19.
+ * The last block in each sector is the Sector Trailer like above.
+ *
+ * MIFARE Ultralight (MF0ICU1):
+ * Has 16 pages of 4 bytes = 64 bytes.
+ * Pages 0 + 1 is used for the 7-byte UID.
+ * Page 2 contains the last chech digit for the UID, one byte manufacturer internal data, and the lock bytes (see http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf section 8.5.2)
+ * Page 3 is OTP, One Time Programmable bits. Once set to 1 they cannot revert to 0.
+ * Pages 4-15 are read/write unless blocked by the lock bytes in page 2.
+ * MIFARE Ultralight C (MF0ICU2):
+ * Has 48 pages of 4 bytes = 64 bytes.
+ * Pages 0 + 1 is used for the 7-byte UID.
+ * Page 2 contains the last chech digit for the UID, one byte manufacturer internal data, and the lock bytes (see http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf section 8.5.2)
+ * Page 3 is OTP, One Time Programmable bits. Once set to 1 they cannot revert to 0.
+ * Pages 4-39 are read/write unless blocked by the lock bytes in page 2.
+ * Page 40 Lock bytes
+ * Page 41 16 bit one way counter
+ * Pages 42-43 Authentication configuration
+ * Pages 44-47 Authentication key
+ */
+#ifndef MFRC522_h
+#define MFRC522_h
+
+#include "mbed.h"
+
+/**
+* MFRC522 example
+*
+* @code
+* #include "mbed.h"
+* #include "MFRC522.h"
+*
+* //KL25Z Pins for MFRC522 SPI interface
+* #define SPI_MOSI PTC6
+* #define SPI_MISO PTC7
+* #define SPI_SCLK PTC5
+* #define SPI_CS PTC4
+* // KL25Z Pin for MFRC522 reset
+* #define MF_RESET PTC3
+* // KL25Z Pins for Debug UART port
+* #define UART_RX PTA1
+* #define UART_TX PTA2
+*
+* DigitalOut LedRed (LED_RED);
+* DigitalOut LedGreen (LED_GREEN);
+*
+* Serial DebugUART(UART_TX, UART_RX);
+* MFRC522 RfChip (SPI_MOSI, SPI_MISO, SPI_SCLK, SPI_CS, MF_RESET);
+*
+* int main(void) {
+* // Set debug UART speed
+* DebugUART.baud(115200);
+*
+* // Init. RC522 Chip
+* RfChip.PCD_Init();
+*
+* while (true) {
+* LedRed = 1;
+* LedGreen = 1;
+*
+* // Look for new cards
+* if ( ! RfChip.PICC_IsNewCardPresent())
+* {
+* wait_ms(500);
+* continue;
+* }
+*
+* LedRed = 0;
+*
+* // Select one of the cards
+* if ( ! RfChip.PICC_ReadCardSerial())
+* {
+* wait_ms(500);
+* continue;
+* }
+*
+* LedRed = 1;
+* LedGreen = 0;
+*
+* // Print Card UID
+* printf("Card UID: ");
+* for (uint8_t i = 0; i < RfChip.uid.size; i++)
+* {
+* printf(" %X02", RfChip.uid.uidByte[i]);
+* }
+* printf("\n\r");
+*
+* // Print Card type
+* uint8_t piccType = RfChip.PICC_GetType(RfChip.uid.sak);
+* printf("PICC Type: %s \n\r", RfChip.PICC_GetTypeName(piccType));
+* wait_ms(1000);
+* }
+* }
+* @endcode
+*/
+
+class MFRC522 {
+public:
+
+ /**
+ * MFRC522 registers (described in chapter 9 of the datasheet).
+ * When using SPI all addresses are shifted one bit left in the "SPI address byte" (section 8.1.2.3)
+ */
+ enum PCD_Register {
+ // Page 0: Command and status
+ // 0x00 // reserved for future use
+ CommandReg = 0x01 << 1, // starts and stops command execution
+ ComIEnReg = 0x02 << 1, // enable and disable interrupt request control bits
+ DivIEnReg = 0x03 << 1, // enable and disable interrupt request control bits
+ ComIrqReg = 0x04 << 1, // interrupt request bits
+ DivIrqReg = 0x05 << 1, // interrupt request bits
+ ErrorReg = 0x06 << 1, // error bits showing the error status of the last command executed
+ Status1Reg = 0x07 << 1, // communication status bits
+ Status2Reg = 0x08 << 1, // receiver and transmitter status bits
+ FIFODataReg = 0x09 << 1, // input and output of 64 byte FIFO buffer
+ FIFOLevelReg = 0x0A << 1, // number of bytes stored in the FIFO buffer
+ WaterLevelReg = 0x0B << 1, // level for FIFO underflow and overflow warning
+ ControlReg = 0x0C << 1, // miscellaneous control registers
+ BitFramingReg = 0x0D << 1, // adjustments for bit-oriented frames
+ CollReg = 0x0E << 1, // bit position of the first bit-collision detected on the RF interface
+ // 0x0F // reserved for future use
+
+ // Page 1:Command
+ // 0x10 // reserved for future use
+ ModeReg = 0x11 << 1, // defines general modes for transmitting and receiving
+ TxModeReg = 0x12 << 1, // defines transmission data rate and framing
+ RxModeReg = 0x13 << 1, // defines reception data rate and framing
+ TxControlReg = 0x14 << 1, // controls the logical behavior of the antenna driver pins TX1 and TX2
+ TxASKReg = 0x15 << 1, // controls the setting of the transmission modulation
+ TxSelReg = 0x16 << 1, // selects the internal sources for the antenna driver
+ RxSelReg = 0x17 << 1, // selects internal receiver settings
+ RxThresholdReg = 0x18 << 1, // selects thresholds for the bit decoder
+ DemodReg = 0x19 << 1, // defines demodulator settings
+ // 0x1A // reserved for future use
+ // 0x1B // reserved for future use
+ MfTxReg = 0x1C << 1, // controls some MIFARE communication transmit parameters
+ MfRxReg = 0x1D << 1, // controls some MIFARE communication receive parameters
+ // 0x1E // reserved for future use
+ SerialSpeedReg = 0x1F << 1, // selects the speed of the serial UART interface
+
+ // Page 2: Configuration
+ // 0x20 // reserved for future use
+ CRCResultRegH = 0x21 << 1, // shows the MSB and LSB values of the CRC calculation
+ CRCResultRegL = 0x22 << 1,
+ // 0x23 // reserved for future use
+ ModWidthReg = 0x24 << 1, // controls the ModWidth setting?
+ // 0x25 // reserved for future use
+ RFCfgReg = 0x26 << 1, // configures the receiver gain
+ GsNReg = 0x27 << 1, // selects the conductance of the antenna driver pins TX1 and TX2 for modulation
+ CWGsPReg = 0x28 << 1, // defines the conductance of the p-driver output during periods of no modulation
+ ModGsPReg = 0x29 << 1, // defines the conductance of the p-driver output during periods of modulation
+ TModeReg = 0x2A << 1, // defines settings for the internal timer
+ TPrescalerReg = 0x2B << 1, // the lower 8 bits of the TPrescaler value. The 4 high bits are in TModeReg.
+ TReloadRegH = 0x2C << 1, // defines the 16-bit timer reload value
+ TReloadRegL = 0x2D << 1,
+ TCntValueRegH = 0x2E << 1, // shows the 16-bit timer value
+ TCntValueRegL = 0x2F << 1,
+
+ // Page 3:Test Registers
+ // 0x30 // reserved for future use
+ TestSel1Reg = 0x31 << 1, // general test signal configuration
+ TestSel2Reg = 0x32 << 1, // general test signal configuration
+ TestPinEnReg = 0x33 << 1, // enables pin output driver on pins D1 to D7
+ TestPinValueReg = 0x34 << 1, // defines the values for D1 to D7 when it is used as an I/O bus
+ TestBusReg = 0x35 << 1, // shows the status of the internal test bus
+ AutoTestReg = 0x36 << 1, // controls the digital self test
+ VersionReg = 0x37 << 1, // shows the software version
+ AnalogTestReg = 0x38 << 1, // controls the pins AUX1 and AUX2
+ TestDAC1Reg = 0x39 << 1, // defines the test value for TestDAC1
+ TestDAC2Reg = 0x3A << 1, // defines the test value for TestDAC2
+ TestADCReg = 0x3B << 1 // shows the value of ADC I and Q channels
+ // 0x3C // reserved for production tests
+ // 0x3D // reserved for production tests
+ // 0x3E // reserved for production tests
+ // 0x3F // reserved for production tests
+ };
+
+ // MFRC522 commands Described in chapter 10 of the datasheet.
+ enum PCD_Command {
+ PCD_Idle = 0x00, // no action, cancels current command execution
+ PCD_Mem = 0x01, // stores 25 bytes into the internal buffer
+ PCD_GenerateRandomID = 0x02, // generates a 10-byte random ID number
+ PCD_CalcCRC = 0x03, // activates the CRC coprocessor or performs a self test
+ PCD_Transmit = 0x04, // transmits data from the FIFO buffer
+ PCD_NoCmdChange = 0x07, // no command change, can be used to modify the CommandReg register bits without affecting the command, for example, the PowerDown bit
+ PCD_Receive = 0x08, // activates the receiver circuits
+ PCD_Transceive = 0x0C, // transmits data from FIFO buffer to antenna and automatically activates the receiver after transmission
+ PCD_MFAuthent = 0x0E, // performs the MIFARE standard authentication as a reader
+ PCD_SoftReset = 0x0F // resets the MFRC522
+ };
+
+ // Commands sent to the PICC.
+ enum PICC_Command {
+ // The commands used by the PCD to manage communication with several PICCs (ISO 14443-3, Type A, section 6.4)
+ PICC_CMD_REQA = 0x26, // REQuest command, Type A. Invites PICCs in state IDLE to go to READY and prepare for anticollision or selection. 7 bit frame.
+ PICC_CMD_WUPA = 0x52, // 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.
+ PICC_CMD_CT = 0x88, // Cascade Tag. Not really a command, but used during anti collision.
+ PICC_CMD_SEL_CL1 = 0x93, // Anti collision/Select, Cascade Level 1
+ PICC_CMD_SEL_CL2 = 0x95, // Anti collision/Select, Cascade Level 1
+ PICC_CMD_SEL_CL3 = 0x97, // Anti collision/Select, Cascade Level 1
+ PICC_CMD_HLTA = 0x50, // HaLT command, Type A. Instructs an ACTIVE PICC to go to state HALT.
+
+ // The commands used for MIFARE Classic (from http://www.nxp.com/documents/data_sheet/MF1S503x.pdf, Section 9)
+ // Use PCD_MFAuthent to authenticate access to a sector, then use these commands to read/write/modify the blocks on the sector.
+ // The read/write commands can also be used for MIFARE Ultralight.
+ PICC_CMD_MF_AUTH_KEY_A = 0x60, // Perform authentication with Key A
+ PICC_CMD_MF_AUTH_KEY_B = 0x61, // Perform authentication with Key B
+ PICC_CMD_MF_READ = 0x30, // Reads one 16 byte block from the authenticated sector of the PICC. Also used for MIFARE Ultralight.
+ PICC_CMD_MF_WRITE = 0xA0, // Writes one 16 byte block to the authenticated sector of the PICC. Called "COMPATIBILITY WRITE" for MIFARE Ultralight.
+ PICC_CMD_MF_DECREMENT = 0xC0, // Decrements the contents of a block and stores the result in the internal data register.
+ PICC_CMD_MF_INCREMENT = 0xC1, // Increments the contents of a block and stores the result in the internal data register.
+ PICC_CMD_MF_RESTORE = 0xC2, // Reads the contents of a block into the internal data register.
+ PICC_CMD_MF_TRANSFER = 0xB0, // Writes the contents of the internal data register to a block.
+
+ // The commands used for MIFARE Ultralight (from http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf, Section 8.6)
+ // The PICC_CMD_MF_READ and PICC_CMD_MF_WRITE can also be used for MIFARE Ultralight.
+ PICC_CMD_UL_WRITE = 0xA2 // Writes one 4 byte page to the PICC.
+ };
+
+ // MIFARE constants that does not fit anywhere else
+ enum MIFARE_Misc {
+ MF_ACK = 0xA, // The MIFARE Classic uses a 4 bit ACK/NAK. Any other value than 0xA is NAK.
+ MF_KEY_SIZE = 6 // A Mifare Crypto1 key is 6 bytes.
+ };
+
+ // PICC types we can detect. Remember to update PICC_GetTypeName() if you add more.
+ enum PICC_Type {
+ PICC_TYPE_UNKNOWN = 0,
+ PICC_TYPE_ISO_14443_4 = 1, // PICC compliant with ISO/IEC 14443-4
+ PICC_TYPE_ISO_18092 = 2, // PICC compliant with ISO/IEC 18092 (NFC)
+ PICC_TYPE_MIFARE_MINI = 3, // MIFARE Classic protocol, 320 bytes
+ PICC_TYPE_MIFARE_1K = 4, // MIFARE Classic protocol, 1KB
+ PICC_TYPE_MIFARE_4K = 5, // MIFARE Classic protocol, 4KB
+ PICC_TYPE_MIFARE_UL = 6, // MIFARE Ultralight or Ultralight C
+ PICC_TYPE_MIFARE_PLUS = 7, // MIFARE Plus
+ PICC_TYPE_TNP3XXX = 8, // Only mentioned in NXP AN 10833 MIFARE Type Identification Procedure
+ PICC_TYPE_NOT_COMPLETE = 255 // SAK indicates UID is not complete.
+ };
+
+ // Return codes from the functions in this class. Remember to update GetStatusCodeName() if you add more.
+ enum StatusCode {
+ STATUS_OK = 1, // Success
+ STATUS_ERROR = 2, // Error in communication
+ STATUS_COLLISION = 3, // Collision detected
+ STATUS_TIMEOUT = 4, // Timeout in communication.
+ STATUS_NO_ROOM = 5, // A buffer is not big enough.
+ STATUS_INTERNAL_ERROR = 6, // Internal error in the code. Should not happen ;-)
+ STATUS_INVALID = 7, // Invalid argument.
+ STATUS_CRC_WRONG = 8, // The CRC_A does not match
+ STATUS_MIFARE_NACK = 9 // A MIFARE PICC responded with NAK.
+ };
+
+ // A struct used for passing the UID of a PICC.
+ typedef struct {
+ uint8_t size; // Number of bytes in the UID. 4, 7 or 10.
+ uint8_t uidByte[10];
+ char uidcheck[100];
+ uint8_t sak; // The SAK (Select acknowledge) byte returned from the PICC after successful selection.
+ } Uid;
+
+ // A struct used for passing a MIFARE Crypto1 key
+ typedef struct {
+ uint8_t keyByte[MF_KEY_SIZE];
+ } MIFARE_Key;
+
+ // Member variables
+ Uid uid; // Used by PICC_ReadCardSerial().
+
+ // Size of the MFRC522 FIFO
+ static const uint8_t FIFO_SIZE = 64; // The FIFO is 64 bytes.
+
+ /**
+ * MFRC522 constructor
+ *
+ * @param mosi SPI MOSI pin
+ * @param miso SPI MISO pin
+ * @param sclk SPI SCLK pin
+ * @param cs SPI CS pin
+ * @param reset Reset pin
+ */
+ MFRC522(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName reset);
+
+ /**
+ * MFRC522 destructor
+ */
+ ~MFRC522();
+
+
+ // ************************************************************************************
+ //! @name Functions for manipulating the MFRC522
+ // ************************************************************************************
+ //@{
+
+ /**
+ * Initializes the MFRC522 chip.
+ */
+ void PCD_Init (void);
+
+ /**
+ * Performs a soft reset on the MFRC522 chip and waits for it to be ready again.
+ */
+ void PCD_Reset (void);
+
+ /**
+ * Turns the antenna on by enabling pins TX1 and TX2.
+ * After a reset these pins disabled.
+ */
+ void PCD_AntennaOn (void);
+
+ /**
+ * Writes a byte to the specified register in the MFRC522 chip.
+ * The interface is described in the datasheet section 8.1.2.
+ *
+ * @param reg The register to write to. One of the PCD_Register enums.
+ * @param value The value to write.
+ */
+ void PCD_WriteRegister (uint8_t reg, uint8_t value);
+
+ /**
+ * Writes a number of bytes to the specified register in the MFRC522 chip.
+ * The interface is described in the datasheet section 8.1.2.
+ *
+ * @param reg The register to write to. One of the PCD_Register enums.
+ * @param count The number of bytes to write to the register
+ * @param values The values to write. Byte array.
+ */
+ void PCD_WriteRegister (uint8_t reg, uint8_t count, uint8_t *values);
+
+ /**
+ * Reads a byte from the specified register in the MFRC522 chip.
+ * The interface is described in the datasheet section 8.1.2.
+ *
+ * @param reg The register to read from. One of the PCD_Register enums.
+ * @returns Register value
+ */
+ uint8_t PCD_ReadRegister (uint8_t reg);
+
+ /**
+ * Reads a number of bytes from the specified register in the MFRC522 chip.
+ * The interface is described in the datasheet section 8.1.2.
+ *
+ * @param reg The register to read from. One of the PCD_Register enums.
+ * @param count The number of bytes to read.
+ * @param values Byte array to store the values in.
+ * @param rxAlign Only bit positions rxAlign..7 in values[0] are updated.
+ */
+ void PCD_ReadRegister (uint8_t reg, uint8_t count, uint8_t *values, uint8_t rxAlign = 0);
+
+ /**
+ * Sets the bits given in mask in register reg.
+ *
+ * @param reg The register to update. One of the PCD_Register enums.
+ * @param mask The bits to set.
+ */
+ void PCD_SetRegisterBits(uint8_t reg, uint8_t mask);
+
+ /**
+ * Clears the bits given in mask from register reg.
+ *
+ * @param reg The register to update. One of the PCD_Register enums.
+ * @param mask The bits to clear.
+ */
+ void PCD_ClrRegisterBits(uint8_t reg, uint8_t mask);
+
+ /**
+ * Use the CRC coprocessor in the MFRC522 to calculate a CRC_A.
+ *
+ * @param data Pointer to the data to transfer to the FIFO for CRC calculation.
+ * @param length The number of bytes to transfer.
+ * @param result Pointer to result buffer. Result is written to result[0..1], low byte first.
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PCD_CalculateCRC (uint8_t *data, uint8_t length, uint8_t *result);
+
+ /**
+ * Executes the Transceive command.
+ * CRC validation can only be done if backData and backLen are specified.
+ *
+ * @param sendData Pointer to the data to transfer to the FIFO.
+ * @param sendLen Number of bytes to transfer to the FIFO.
+ * @param backData NULL or pointer to buffer if data should be read back after executing the command.
+ * @param backLen Max number of bytes to write to *backData. Out: The number of bytes returned.
+ * @param validBits The number of valid bits in the last byte. 0 for 8 valid bits. Default NULL.
+ * @param rxAlign Defines the bit position in backData[0] for the first bit received. Default 0.
+ * @param checkCRC True => The last two bytes of the response is assumed to be a CRC_A that must be validated.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PCD_TransceiveData (uint8_t *sendData,
+ uint8_t sendLen,
+ uint8_t *backData,
+ uint8_t *backLen,
+ uint8_t *validBits = NULL,
+ uint8_t rxAlign = 0,
+ bool checkCRC = false);
+
+
+ /**
+ * Transfers data to the MFRC522 FIFO, executes a commend, waits for completion and transfers data back from the FIFO.
+ * CRC validation can only be done if backData and backLen are specified.
+ *
+ * @param command The command to execute. One of the PCD_Command enums.
+ * @param waitIRq The bits in the ComIrqReg register that signals successful completion of the command.
+ * @param sendData Pointer to the data to transfer to the FIFO.
+ * @param sendLen Number of bytes to transfer to the FIFO.
+ * @param backData NULL or pointer to buffer if data should be read back after executing the command.
+ * @param backLen In: Max number of bytes to write to *backData. Out: The number of bytes returned.
+ * @param validBits In/Out: The number of valid bits in the last byte. 0 for 8 valid bits.
+ * @param rxAlign In: Defines the bit position in backData[0] for the first bit received. Default 0.
+ * @param checkCRC In: True => The last two bytes of the response is assumed to be a CRC_A that must be validated.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PCD_CommunicateWithPICC(uint8_t command,
+ uint8_t waitIRq,
+ uint8_t *sendData,
+ uint8_t sendLen,
+ uint8_t *backData = NULL,
+ uint8_t *backLen = NULL,
+ uint8_t *validBits = NULL,
+ uint8_t rxAlign = 0,
+ bool checkCRC = false);
+
+ /**
+ * 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.
+ *
+ * @param bufferATQA The buffer to store the ATQA (Answer to request) in
+ * @param bufferSize Buffer size, at least two bytes. Also number of bytes returned if STATUS_OK.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PICC_RequestA (uint8_t *bufferATQA, uint8_t *bufferSize);
+
+ /**
+ * 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.
+ *
+ * @param bufferATQA The buffer to store the ATQA (Answer to request) in
+ * @param bufferSize Buffer size, at least two bytes. Also number of bytes returned if STATUS_OK.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PICC_WakeupA (uint8_t *bufferATQA, uint8_t *bufferSize);
+
+ /**
+ * 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.
+ *
+ * @param command The command to send - PICC_CMD_REQA or PICC_CMD_WUPA
+ * @param bufferATQA The buffer to store the ATQA (Answer to request) in
+ * @param bufferSize Buffer size, at least two bytes. Also number of bytes returned if STATUS_OK.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PICC_REQA_or_WUPA (uint8_t command, uint8_t *bufferATQA, uint8_t *bufferSize);
+
+ /**
+ * 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?
+ *
+ *
+ * @param uid Pointer to Uid struct. Normally output, but can also be used to supply a known UID.
+ * @param validBits The number of known UID bits supplied in *uid. Normally 0. If set you must also supply uid->size.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PICC_Select (Uid *uid, uint8_t validBits = 0);
+
+ /**
+ * Instructs a PICC in state ACTIVE(*) to go to state HALT.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PICC_HaltA (void);
+
+ // ************************************************************************************
+ //@}
+
+
+ // ************************************************************************************
+ //! @name 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.
+ *
+ * @param command PICC_CMD_MF_AUTH_KEY_A or PICC_CMD_MF_AUTH_KEY_B
+ * @param blockAddr The block number. See numbering in the comments in the .h file.
+ * @param key Pointer to the Crypteo1 key to use (6 bytes)
+ * @param uid Pointer to Uid struct. The first 4 bytes of the UID is used.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise. Probably STATUS_TIMEOUT if you supply the wrong key.
+ */
+ uint8_t PCD_Authenticate (uint8_t command, uint8_t blockAddr, MIFARE_Key *key, Uid *uid);
+
+ /**
+ * 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 PCD_StopCrypto1 (void);
+
+ /**
+ * 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.
+ *
+ * @param blockAddr MIFARE Classic: The block (0-0xff) number. MIFARE Ultralight: The first page to return data from.
+ * @param buffer The buffer to store the data in
+ * @param bufferSize Buffer size, at least 18 bytes. Also number of bytes returned if STATUS_OK.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_Read (uint8_t blockAddr, uint8_t *buffer, uint8_t *bufferSize);
+
+ /**
+ * 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 opretaion 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.
+ *
+ * @param blockAddr MIFARE Classic: The block (0-0xff) number. MIFARE Ultralight: The page (2-15) to write to.
+ * @param buffer The 16 bytes to write to the PICC
+ * @param bufferSize Buffer size, must be at least 16 bytes. Exactly 16 bytes are written.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_Write (uint8_t blockAddr, uint8_t *buffer, uint8_t bufferSize);
+
+ /**
+ * Writes a 4 byte page to the active MIFARE Ultralight PICC.
+ *
+ * @param page The page (2-15) to write to.
+ * @param buffer The 4 bytes to write to the PICC
+ * @param bufferSize Buffer size, must be at least 4 bytes. Exactly 4 bytes are written.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_UltralightWrite(uint8_t page, uint8_t *buffer, uint8_t bufferSize);
+
+ /**
+ * 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.
+ *
+ * @param blockAddr The block (0-0xff) number.
+ * @param delta This number is subtracted from the value of block blockAddr.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_Decrement (uint8_t blockAddr, uint32_t delta);
+
+ /**
+ * 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.
+ *
+ * @param blockAddr The block (0-0xff) number.
+ * @param delta This number is added to the value of block blockAddr.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_Increment (uint8_t blockAddr, uint32_t delta);
+
+ /**
+ * 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.
+ *
+ * @param blockAddr The block (0-0xff) number.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_Restore (uint8_t blockAddr);
+
+ /**
+ * 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].
+ *
+ * @param blockAddr The block (0-0xff) number.
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_Transfer (uint8_t blockAddr);
+
+ // ************************************************************************************
+ //@}
+
+
+ // ************************************************************************************
+ //! @name 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.
+ *
+ * @param sendData Pointer to the data to transfer to the FIFO. Do NOT include the CRC_A.
+ * @param sendLen Number of bytes in sendData.
+ * @param acceptTimeout True => A timeout is also success
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t PCD_MIFARE_Transceive(uint8_t *sendData, uint8_t sendLen, bool acceptTimeout = false);
+
+ /**
+ * Translates the SAK (Select Acknowledge) to a PICC type.
+ *
+ * @param sak The SAK byte returned from PICC_Select().
+ *
+ * @return PICC_Type
+ */
+ uint8_t PICC_GetType (uint8_t sak);
+
+ /**
+ * Returns a string pointer to the PICC type name.
+ *
+ * @param type One of the PICC_Type enums.
+ *
+ * @return A string pointer to the PICC type name.
+ */
+ char* PICC_GetTypeName (uint8_t type);
+
+ /**
+ * Returns a string pointer to a status code name.
+ *
+ * @param code One of the StatusCode enums.
+ *
+ * @return A string pointer to a status code name.
+ */
+ char* GetStatusCodeName (uint8_t code);
+
+ /**
+ * 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).
+ *
+ * @param accessBitBuffer Pointer to byte 6, 7 and 8 in the sector trailer. Bytes [0..2] will be set.
+ * @param g0 Access bits [C1 C2 C3] for block 0 (for sectors 0-31) or blocks 0-4 (for sectors 32-39)
+ * @param g1 Access bits [C1 C2 C3] for block 1 (for sectors 0-31) or blocks 5-9 (for sectors 32-39)
+ * @param g2 Access bits [C1 C2 C3] for block 2 (for sectors 0-31) or blocks 10-14 (for sectors 32-39)
+ * @param g3 Access bits [C1 C2 C3] for the sector trailer, block 3 (for sectors 0-31) or block 15 (for sectors 32-39)
+ */
+ void MIFARE_SetAccessBits (uint8_t *accessBitBuffer,
+ uint8_t g0,
+ uint8_t g1,
+ uint8_t g2,
+ uint8_t g3);
+
+ // ************************************************************************************
+ //@}
+
+
+ // ************************************************************************************
+ //! @name 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 PICC_IsNewCardPresent(void);
+
+ /**
+ * 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 PICC_ReadCardSerial (void);
+
+ // ************************************************************************************
+ //@}
+
+
+private:
+ SPI m_SPI;
+ DigitalOut m_CS;
+ DigitalOut m_RESET;
+
+ /**
+ * Helper function for the two-step MIFARE Classic protocol operations Decrement, Increment and Restore.
+ *
+ * @param command The command to use
+ * @param blockAddr The block (0-0xff) number.
+ * @param data The data to transfer in step 2
+ *
+ * @return STATUS_OK on success, STATUS_??? otherwise.
+ */
+ uint8_t MIFARE_TwoStepHelper(uint8_t command, uint8_t blockAddr, uint32_t data);
+};
+
+#endif