diff --git a/MFRC522.cpp b/MFRC522.cpp index 441f1e9..3f67779 100644 --- a/MFRC522.cpp +++ b/MFRC522.cpp @@ -272,6 +272,105 @@ void MFRC522::PCD_SetAntennaGain(byte mask) { } } // 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); + + // Reference values based on firmware version; taken from 16.1.1 in spec. + // Version 1.0 + byte referenceV1_0[] = { + 0x00, 0xC6, 0x37, 0xD5, 0x32, 0xB7, 0x57, 0x5C, + 0xC2, 0xD8, 0x7C, 0x4D, 0xD9, 0x70, 0xC7, 0x73, + 0x10, 0xE6, 0xD2, 0xAA, 0x5E, 0xA1, 0x3E, 0x5A, + 0x14, 0xAF, 0x30, 0x61, 0xC9, 0x70, 0xDB, 0x2E, + 0x64, 0x22, 0x72, 0xB5, 0xBD, 0x65, 0xF4, 0xEC, + 0x22, 0xBC, 0xD3, 0x72, 0x35, 0xCD, 0xAA, 0x41, + 0x1F, 0xA7, 0xF3, 0x53, 0x14, 0xDE, 0x7E, 0x02, + 0xD9, 0x0F, 0xB5, 0x5E, 0x25, 0x1D, 0x29, 0x79 + }; + + // Version 2.0 + byte referenceV2_0[] = { + 0x00, 0xEB, 0x66, 0xBA, 0x57, 0xBF, 0x23, 0x95, + 0xD0, 0xE3, 0x0D, 0x3D, 0x27, 0x89, 0x5C, 0xDE, + 0x9D, 0x3B, 0xA7, 0x00, 0x21, 0x5B, 0x89, 0x82, + 0x51, 0x3A, 0xEB, 0x02, 0x0C, 0xA5, 0x00, 0x49, + 0x7C, 0x84, 0x4D, 0xB3, 0xCC, 0xD2, 0x1B, 0x81, + 0x5D, 0x48, 0x76, 0xD5, 0x71, 0x61, 0x21, 0xA9, + 0x86, 0x96, 0x83, 0x38, 0xCF, 0x9D, 0x5B, 0x6D, + 0xDC, 0x15, 0xBA, 0x3E, 0x7D, 0x95, 0x3B, 0x2F + }; + + // Pick the appropriate reference values + byte *reference; + switch (version) { + case 0x91: // Version 1.0 + reference = referenceV1_0; + break; + case 0x92: // Version 2.0 + reference = 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] != reference[i]) { + return false; + } + } + + // Test passed; all is good. + return true; +} // End PCD_PerformSelfTest() + ///////////////////////////////////////////////////////////////////////////////////// // Functions for communicating with PICCs ///////////////////////////////////////////////////////////////////////////////////// diff --git a/MFRC522.h b/MFRC522.h index 563dc1c..8a4e2ee 100644 --- a/MFRC522.h +++ b/MFRC522.h @@ -290,6 +290,7 @@ public: void PCD_AntennaOff(); byte PCD_GetAntennaGain(); void PCD_SetAntennaGain(byte mask); + bool PCD_PerformSelfTest(); ///////////////////////////////////////////////////////////////////////////////////// // Functions for communicating with PICCs