miguelbalboa · Nov 7, 2018 · Nov 11, 2018 · Nov 15, 2018 · Mar 9, 2019 · Mar 28, 2020
diff --git a/README.rst b/README.rst
@@ -14,7 +14,7 @@ Arduino library for MFRC522 and other RFID RC522 based modules.
 
 Read and write different types of Radio-Frequency IDentification (RFID) cards
 on your Arduino using a RC522 based reader connected via the Serial Peripheral
-Interface (SPI) interface.
+Interface (SPI) interface, the i2c interface or the UART.
 
 
 .. _development:
@@ -348,7 +348,7 @@ It has been extended with functionality to alter sector 0 on Chinese UID changea
 
 Maintained by miguelbalboa until 2016.
 Maintained by Rotzbua from 2016 until 2018.
-
+Updated b dirkx from mid 2018.
 
 .. _arduino: https://arduino.cc/
 .. _ebay: https://www.ebay.com/

diff --git a/changes.txt b/changes.txt
@@ -1,5 +1,10 @@
 -- Add changes to unreleased tag until we make a release.
 
+28 March 2020, v1.5.0
+- Added support for I2C and UART readers
+- Added callback functions (so you do not need to poll)
+- Addex examples for these callbacks.
+
 27 Oct 2018, v1.4.3
 - Added counterfeit detection and hint about bad boards
 - Improved hardware based reset

diff --git a/examples/Minimal-I2C/Minimal-I2C.ino b/examples/Minimal-I2C/Minimal-I2C.ino
@@ -0,0 +1,84 @@
+/*
+   --------------------------------------------------------------------------------------------------------------------
+   Example sketch/program showing how to read data from a PICC to serial.
+   --------------------------------------------------------------------------------------------------------------------
+   This is a MFRC522 library example; for further details and other examples see: https://github.com/miguelbalboa/rfid
+
+   Example sketch/program showing how to read data from a PICC (that is: a RFID Tag or Card) using a MFRC522 based RFID
+   Reader on the Arduino SPI interface.
+
+   When the Arduino and the MFRC522 module are connected (see the pin layout below), load this sketch into Arduino IDE
+   then verify/compile and upload it. To see the output: use Tools, Serial Monitor of the IDE (hit Ctrl+Shft+M). When
+   you present a PICC (that is: a RFID Tag or Card) at reading distance of the MFRC522 Reader/PCD, the serial output
+   will show the ID/UID, type and any data blocks it can read. Note: you may see "Timeout in communication" messages
+   when removing the PICC from reading distance too early.
+
+   @license Released into the public domain.
+
+   Typical pin layout used:
+   -----------------------------------------------------------------------------------------
+               MFRC522      Arduino       Arduino   Arduino    Arduino          Arduino
+               Reader/PCD   Uno/101       Mega      Nano v3    Leonardo/Micro   Pro Micro   Due/Mega2560
+   Signal      Pin          Pin           Pin       Pin        Pin              Pin
+   -----------------------------------------------------------------------------------------
+   RST/Reset   RST          9             5         D9         RESET/ICSP-5     23         9
+   scl	       CLK	    5		  5 		      3                                     22
+   sda         SC 	    4		  4           2                                     21
+
+*/
+#include <MFRC522.h>
+
+constexpr uint8_t RST_PIN = 2;          // Configurable, see typical pin layout above
+
+// The default address of the MFRC522 is 0X3C -- specify it here if you
+// have it configured differently (pull up/down pins on the chip).
+//
+// MFRC522_I2C mfrc522(RST_PIN, 0x28 /*, chipAddr */);  		// Create MFRC522 instance
+
+TwoWire i2cBus = TwoWire(0);
+MFRC522_I2C dev = MFRC522_I2C(RST_PIN, 0x28, i2cBus);
+MFRC522 mfrc522 = MFRC522(dev);
+
+void setup() {
+  Serial.begin(115200);	// Initialize serial communications with the PC
+  while (!Serial);		  // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
+
+  i2cBus.begin(5, 4, 400000); 
+
+  mfrc522.PCD_Init();		// Init MFRC522
+  mfrc522.PCD_DumpVersionToSerial();	// Show details of PCD - MFRC522 Card Reader details
+
+  Serial.println(F("Scan PICC to see UID, SAK, type, and data blocks..."));
+}
+
+void loop() {
+  // Look for new cards
+  if ( ! mfrc522.PICC_IsNewCardPresent()) {
+    return; // no card in sight.
+  }
+
+  // Select one of the cards
+  if ( ! mfrc522.PICC_ReadCardSerial()) {
+    Serial.println("Bad read (was card removed too quickly?)");
+    return;
+  };
+
+  if ( mfrc522.uid.size == 0) {
+    Serial.println("Bad card read (size = 0)");
+    return;
+  }
+
+  char buff[sizeof(mfrc522.uid.uidByte)* 5] = { 0 };
+  for (int i = 0; i < mfrc522.uid.size; i++) {
+    char tag[5]; // 3 digits, dash and \0.
+    snprintf(buff, sizeof(buff), "%s%d", i ? "-" : "", mfrc522.uid.uidByte[i]);
+    strncat(buff, tag, sizeof(tag));
+  };
+  Serial.println("Good scan: ");
+  Serial.println(buff);
+
+  // disengage with the card.
+  //
+  mfrc522.PICC_HaltA();
+}
+
diff --git a/examples/Minimal-SPI/Minimal-SPI.ino b/examples/Minimal-SPI/Minimal-SPI.ino
@@ -0,0 +1,102 @@
+/*
+   --------------------------------------------------------------------------------------------------------------------
+   Example sketch/program showing how to read data from a PICC to serial.
+   --------------------------------------------------------------------------------------------------------------------
+   This is a MFRC522 library example; for further details and other examples see: https://github.com/miguelbalboa/rfid
+
+   Example sketch/program showing how to read data from a PICC (that is: a RFID Tag or Card) using a MFRC522 based RFID
+   Reader on the Arduino SPI interface.
+
+   When the Arduino and the MFRC522 module are connected (see the pin layout below), load this sketch into Arduino IDE
+   then verify/compile and upload it. To see the output: use Tools, Serial Monitor of the IDE (hit Ctrl+Shft+M). When
+   you present a PICC (that is: a RFID Tag or Card) at reading distance of the MFRC522 Reader/PCD, the serial output
+   will show the ID/UID, type and any data blocks it can read. Note: you may see "Timeout in communication" messages
+   when removing the PICC from reading distance too early.
+
+   If your reader supports it, this sketch/program will read all the PICCs presented (that is: multiple tag reading).
+   So if you stack two or more PICCs on top of each other and present them to the reader, it will first output all
+   details of the first and then the next PICC. Note that this may take some time as all data blocks are dumped, so
+   keep the PICCs at reading distance until complete.
+
+   @license Released into the public domain.
+
+   Typical pin layout used:
+   -----------------------------------------------------------------------------------------
+               MFRC522      Arduino       Arduino   Arduino    Arduino          Arduino
+               Reader/PCD   Uno/101       Mega      Nano v3    Leonardo/Micro   Pro Micro
+   Signal      Pin          Pin           Pin       Pin        Pin              Pin
+   -----------------------------------------------------------------------------------------
+   RST/Reset   RST          9             5         D9         RESET/ICSP-5     RST
+   SPI SS      SDA(SS)      10            53        D10        10               10
+   SPI MOSI    MOSI         11 / ICSP-4   51        D11        ICSP-4           16
+   SPI MISO    MISO         12 / ICSP-1   50        D12        ICSP-1           14
+   SPI SCK     SCK          13 / ICSP-3   52        D13        ICSP-3           15
+*/
+
+#include <SPI.h>
+#include <MFRC522.h>
+
+constexpr uint8_t RST_PIN = 32;          // Configurable, see typical pin layout above
+constexpr uint8_t SS_PIN =  15;         // Configurable, see typical pin layout above
+
+MFRC522_SPI spiDevice = MFRC522_SPI(SS_PIN, RST_PIN);
+MFRC522 mfrc522 = MFRC522(spiDevice);  // Create MFRC522 instance
+
+// Specify the wiring/pins in more detail.
+//
+// MFRC522_SPI spiDevice = MFRC522_SPI(SS_PIN, RST_PIN, PIN_SCK, PIN_MISO, PIN_MOSI);
+// MFRC522 mfrc522 = MFRC522(spiDevice);  
+//
+// Or do much the same - but also specify the bus
+//
+// SPI spiBus = SPI(HSPI);
+// spiBus.begin(PIN_SCK, PIN_MISO, PIN_MOSI);
+// MFRC522_SPI spiDevice = MFRC522_SPI(SS_PIN, RST_PIN, spiBus);
+// MFRC522 mfrc522 = MFRC522(spiDevice);  
+//
+// And if neeed - also change the bus settings.
+//
+// SPI spiBus = SPI(HSPI);
+// SPISettings spiSettings = SPISettings(SPI_CLOCK_DIV4, MSBFIRST, SPI_MODE0))
+// MFRC522_SPI spiDevice = MFRC522_SPI(SS_PIN, RST_PIN, spiBus, spiBusSettings);
+// MFRC522 mfrc522 = MFRC522(spiDevice); 
+
+void setup() {
+  Serial.begin(9600);		// Initialize serial communications with the PC
+  while (!Serial);		// Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
+
+  SPI.begin(14, 12, 13);
+  mfrc522.PCD_Init();		// Init MFRC522
+  mfrc522.PCD_DumpVersionToSerial();	// Show details of PCD - MFRC522 Card Reader details
+  Serial.println(F("Scan PICC to see UID, SAK, type, and data blocks..."));
+}
+
+void loop() {
+  // Look for new cards
+  if ( ! mfrc522.PICC_IsNewCardPresent()) {
+    return;
+  }
+
+  // Select one of the cards
+  if ( ! mfrc522.PICC_ReadCardSerial()) {
+    Serial.println("Bad read (was card removed too quickly?)");
+    return;
+  }
+
+  if (mfrc522.uid.size == 0) {
+    Serial.println("Bad card (size = 0)");
+  } else {
+    char tag[sizeof(mfrc522.uid.uidByte) * 4] = { 0 };
+    for (int i = 0; i < mfrc522.uid.size; i++) {
+      char buff[5]; // 3 digits, dash and \0.
+      snprintf(buff, sizeof(buff), "%s%d", i ? "-" : "", mfrc522.uid.uidByte[i]);
+      strncat(tag, buff, sizeof(tag));
+    };
+    Serial.println("Good scan: ");
+    Serial.println(tag);
+  };
+
+  // disengage with the card.
+  //
+  mfrc522.PICC_HaltA();
+}
diff --git a/examples/rfid_uart/rfid_uart.ino b/examples/rfid_uart/rfid_uart.ino
@@ -0,0 +1,48 @@
+/*
+ * This example simply changes the state of the LED_PIN based on a known tag code.
+ * This code uses the NodeMCU (ESP-12E) layout for pin assignment.
+ * Pin 16 is the LED next to the USB connector on the NodeMCU board.
+ * Pin 2 is a generic GPIO (used here for initialization of RFID module).
+ */
+
+#include <MFRC522.h>
+
+// Sample tag (assuming four bytes)
+byte TEST_TAG[] = { 0x11, 0xBC, 0x4A, 0x10 };
+
+// Tested on NodeMCU (ESP-12E)
+const unsigned RST_PIN = 2;
+const unsigned LED_PIN = 16;
+const unsigned long RFID_POLLING_PERIOD_MS = 100;
+unsigned long lastTimestamp = 0;
+
+MFRC522_UART mfrc522(Serial, RST_PIN);
+MFRC522 rfid(&mfrc522);
+
+void setup() {
+  pinMode(LED_PIN, OUTPUT);
+
+  // RFID
+  rfid.PCD_Init();
+  rfid.PCD_SetAntennaGain(MFRC522::RxGain_max);
+}
+
+void loop(){
+
+  unsigned long currentTimestamp = millis();
+  if ((currentTimestamp - lastTimestamp) > RFID_POLLING_PERIOD_MS) {
+    lastTimestamp = currentTimestamp;
+
+    if (rfid.PICC_IsNewCardPresent()) {
+      if (rfid.PICC_ReadCardSerial()) {
+
+        // Compares the code obtained from a tag with our TEST_TAG
+        if (memcmp(rfid.uid.uidByte, TEST_TAG, sizeof(TEST_TAG) / sizeof(byte)) == 0) {
+          digitalWrite(LED_PIN, HIGH);
+        } else {
+          digitalWrite(LED_PIN, LOW);
+        }
+      }
+    }
+  }
+}
diff --git a/library.json b/library.json
diff --git a/library.properties b/library.properties
@@ -1,9 +1,9 @@
-name=MFRC522
-version=1.4.3
-author=GithubCommunity
-maintainer=GithubCommunity
-sentence=Arduino RFID Library for MFRC522 (SPI)
-paragraph=Read/Write a RFID Card or Tag using the ISO/IEC 14443A/MIFARE interface.
+name=MFRC522-spi-i2c-uart-async
+version=1.5.1
+author=GithubCommunity,miguelbalboa,dirkx@webweaving.org
+maintainer=GithubCommunity,dirkx@webweaving.org
+sentence=Arduino RFID Library for MFRC522 (SPI, I2C and UART) with asynchroneous callbacks
+paragraph=Read/Write a RFID Card or Tag using the ISO/IEC 14443A/MIFARE interface. Modified from the original miguelbalboa to also support I2C and UART connections and provide, in addition to normal constant polling, an option to do asynchroneous callbacks. I.e. have a function called each time that a valid swipe has happend. Used at the https://makerspaceleiden.nl.
 category=Communication
-url=https://github.com/miguelbalboa/rfid
-architectures=avr,STM32F1,teensy,esp8266,samd
+url=https://github.com/makerspaceleiden/rfid
+architectures=avr,STM32F1,teensy,esp8266,samd,esp32