Merge pull request #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
 /////////////////////////////////////////////////////////////////////////////////////