Merge pull request miguelbalboa#47 from mdxs/exp_range

Adding AttennaOff and get/set of AntennaGain

MFRC522.cpp

@@ -242,6 +242,36 @@ void MFRC522::PCD_AntennaOn() {
 	}
 } // End PCD_AntennaOn()
 
+/**
+ * Turns the antenna off by disabling pins TX1 and TX2.
+ */
+void MFRC522::PCD_AntennaOff() {
+	PCD_ClearRegisterBitMask(RFCfgReg, 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()
+
 /////////////////////////////////////////////////////////////////////////////////////
 // Functions for communicating with PICCs
 /////////////////////////////////////////////////////////////////////////////////////

MFRC522.h

@@ -169,6 +169,22 @@ class MFRC522 {
 		PCD_SoftReset			= 0x0F		// resets the MFRC522
 	};
 
+	// MFRC522 RxGain[2:0] masks, defines the receiver's signal voltage gain factor (on the PCD).
+	// Described in 9.3.3.6 / table 98 of the datasheet at http://www.nxp.com/documents/data_sheet/MFRC522.pdf
+	enum PCD_RxGain {
+		RxGain_18dB				= 0x00 << 4,	// 000b - 18 dB, minimum
+		RxGain_23dB				= 0x01 << 4,	// 001b - 23 dB
+		RxGain_18dB_2			= 0x02 << 4,	// 010b - 18 dB, it seems 010b is a duplicate for 000b
+		RxGain_23dB_2			= 0x03 << 4,	// 011b - 23 dB, it seems 011b is a duplicate for 001b
+		RxGain_33dB				= 0x04 << 4,	// 100b - 33 dB, average, and typical default
+		RxGain_38dB				= 0x05 << 4,	// 101b - 38 dB
+		RxGain_43dB				= 0x06 << 4,	// 110b - 43 dB
+		RxGain_48dB				= 0x07 << 4,	// 111b - 48 dB, maximum
+		RxGain_min				= 0x00 << 4,	// 000b - 18 dB, minimum, convenience for RxGain_18dB
+		RxGain_avg				= 0x04 << 4,	// 100b - 33 dB, average, convenience for RxGain_33dB
+		RxGain_max				= 0x07 << 4		// 111b - 48 dB, maximum, convenience for RxGain_48dB
+	};
+
 	// 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)
@@ -270,6 +286,9 @@ class MFRC522 {
 	void PCD_Init();
 	void PCD_Reset();
 	void PCD_AntennaOn();
+	void PCD_AntennaOff();
+	byte PCD_GetAntennaGain();
+	void PCD_SetAntennaGain(byte mask);
 
 	/////////////////////////////////////////////////////////////////////////////////////
 	// Functions for communicating with PICCs

keywords.txt

@@ -8,6 +8,7 @@
 MFRC522	KEYWORD1
 PCD_Register	KEYWORD1
 PCD_Command	KEYWORD1
+PCD_RxGain	KEYWORD1
 PICC_Command	KEYWORD1
 MIFARE_Misc	KEYWORD1
 PICC_Type	KEYWORD1
@@ -30,6 +31,9 @@ PCD_CalculateCRC	KEYWORD2
 PCD_Init	KEYWORD2
 PCD_Reset	KEYWORD2
 PCD_AntennaOn	KEYWORD2
+PCD_AntennaOff	KEYWORD2
+PCD_GetAntennaGain	KEYWORD2
+PCD_SetAntennaGain	KEYWORD2
 PCD_TransceiveData	KEYWORD2
 PCD_CommunicateWithPICC	KEYWORD2
 PICC_RequestA	KEYWORD2
@@ -120,6 +124,17 @@ PCD_Receive	LITERAL1
 PCD_Transceive 	LITERAL1
 PCD_MFAuthent 	LITERAL1
 PCD_SoftReset	LITERAL1
+RxGain_18dB	LITERAL1
+RxGain_23dB	LITERAL1
+RxGain_18dB_2	LITERAL1
+RxGain_23dB_2	LITERAL1
+RxGain_33dB	LITERAL1
+RxGain_38dB	LITERAL1
+RxGain_43dB	LITERAL1
+RxGain_48dB	LITERAL1
+RxGain_min	LITERAL1
+RxGain_avg	LITERAL1
+RxGain_max	LITERAL1
 PICC_CMD_REQA	LITERAL1
 PICC_CMD_WUPA	LITERAL1
 PICC_CMD_CT	LITERAL1
@@ -158,4 +173,3 @@ STATUS_INVALID	LITERAL1
 STATUS_CRC_WRONG	LITERAL1
 STATUS_MIFARE_NACK	LITERAL1
 FIFO_SIZE	LITERAL1
-