From b86a09792d25455a620c4cdcedf1086aac35ffdb Mon Sep 17 00:00:00 2001
From: Denis Volpato Martins <denisvm@gmail.com>
Date: Sun, 21 Aug 2016 19:52:45 -0300
Subject: [PATCH 1/2] Get SPI SS/CS pin automatically

---
 MFRC522.cpp | 16 ++++++++++++++++
 MFRC522.h   |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/MFRC522.cpp b/MFRC522.cpp
index 6979b8e..7d86049 100644
--- a/MFRC522.cpp
+++ b/MFRC522.cpp
@@ -16,6 +16,14 @@
 MFRC522::MFRC522() {
 } // End constructor
 
+/**
+ * Constructor.
+ * Prepares the output pins.
+ */
+MFRC522::MFRC522(	byte resetPowerDownPin	///< Arduino pin connected to MFRC522's reset and power down input (Pin 6, NRSTPD, active low)
+				): MFRC522(SS, resetPowerDownPin) {
+} // End constructor
+
 /**
  * Constructor.
  * Prepares the output pins.
@@ -217,6 +225,14 @@ void MFRC522::PCD_Init() {
 	PCD_AntennaOn();						// Enable the antenna driver pins TX1 and TX2 (they were disabled by the reset)
 } // End PCD_Init()
 
+/**
+ * Initializes the MFRC522 chip.
+ */
+void MFRC522::PCD_Init(	byte resetPowerDownPin	///< Arduino pin connected to MFRC522's reset and power down input (Pin 6, NRSTPD, active low)
+					) {
+	PCD_Init(SS, resetPowerDownPin);
+} // End PCD_Init()
+
 /**
  * Initializes the MFRC522 chip.
  */
diff --git a/MFRC522.h b/MFRC522.h
index e003451..abb6670 100644
--- a/MFRC522.h
+++ b/MFRC522.h
@@ -322,6 +322,7 @@ public:
 	// Functions for setting up the Arduino
 	/////////////////////////////////////////////////////////////////////////////////////
 	MFRC522();
+	MFRC522(byte resetPowerDownPin);
 	MFRC522(byte chipSelectPin, byte resetPowerDownPin);
 	
 	/////////////////////////////////////////////////////////////////////////////////////
@@ -340,6 +341,7 @@ public:
 	// Functions for manipulating the MFRC522
 	/////////////////////////////////////////////////////////////////////////////////////
 	void PCD_Init();
+	void PCD_Init(byte resetPowerDownPin);
 	void PCD_Init(byte chipSelectPin, byte resetPowerDownPin);
 	void PCD_Reset();
 	void PCD_AntennaOn();

From 4ee20074b23a9f8f5b428b737a6cd0da91c167c7 Mon Sep 17 00:00:00 2001
From: Denis Volpato Martins <denisvm@gmail.com>
Date: Wed, 24 Aug 2016 08:55:49 -0300
Subject: [PATCH 2/2] added SS define comment

---
 MFRC522.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/MFRC522.cpp b/MFRC522.cpp
index 7d86049..6a4fe2d 100644
--- a/MFRC522.cpp
+++ b/MFRC522.cpp
@@ -21,7 +21,7 @@ MFRC522::MFRC522() {
  * Prepares the output pins.
  */
 MFRC522::MFRC522(	byte resetPowerDownPin	///< Arduino pin connected to MFRC522's reset and power down input (Pin 6, NRSTPD, active low)
-				): MFRC522(SS, resetPowerDownPin) {
+				): MFRC522(SS, resetPowerDownPin) { // SS is defined in pins_arduino.h
 } // End constructor
 
 /**
@@ -230,7 +230,7 @@ void MFRC522::PCD_Init() {
  */
 void MFRC522::PCD_Init(	byte resetPowerDownPin	///< Arduino pin connected to MFRC522's reset and power down input (Pin 6, NRSTPD, active low)
 					) {
-	PCD_Init(SS, resetPowerDownPin);
+	PCD_Init(SS, resetPowerDownPin); // SS is defined in pins_arduino.h
 } // End PCD_Init()
 
 /**