RFID for Uno and ESP32s

//  Scissors Example:  RFID.ino
//  Scissors used to grab data from an RFID tag reader 
//  updated 2024 (hex705)

//  Match the BAUD in .begin() call to the BAUD of your reader.
//  Set DELIMITER to -1
//  Set START_BYTE and END_BYTE to match tag structure.

/* circuit 
   vcc= 5V
   gnd = gnd
   s-out of reader to pin 0 (RX arduino UNO ) - remove for upload, reconnect for read
   sn (reader) is enable it must be LOW -- connect to ground or control with pin (in this case 2)
*/

/* 
   indicators
   ironically -- a red LED is good on my reader -- a green led is bad
   -- when the enable pin is pulled LOW (down) teh LED goes red adn tags can be read
*/


// ************   NOTE -- upload challenges   **************
// in this care RFID is using UNO serial pins.
// these are connected to USB 
// !!!   you MUST disconnect the data line to UNO pin 0 to upload, then reconnect to read  !!!!
// ************


// Example developed by hex705 (Steve Daniels)
// github.com/hex705


#include <Scissors.h>

  Scissors RFID_reader;
  
  String newTag = "";
  String oldTag ="";

  int enablePin = 2; // esp 14
  
  
void setup() {
   Serial.begin(2400);

    RFID_reader.begin(Serial); 
   
   // scissors needs to have the package structure set to match RFID tags.
   // each tag send a message of form:
   // START_BYTE payload_of_length_10_bytes END_BYTE
   
     RFID_reader.setStartByte( 0x0A ); // 10 == start_byte
     RFID_reader.setEndByte  ( 0x0D ); // 13 == end_byte
     RFID_reader.setDelimiter( -1 );   // no delimiters 
   
   // all of the above could be replaced with the following
   // RFID_reader.begin(2400,10,13,-1); 

  pinMode(enablePin,OUTPUT);

  digitalWrite(enablePin,LOW); // enable LOW ! 
  Serial.println("rfid testing, setup complete");
} 


void loop () {


  RFID_reader.poll();  // check for messages

  if ( ! newTag.equals(oldTag) ) {
      Serial.println(newTag);                 // only print new tags that are different than last tag  
  } 
       
  oldTag = newTag;
       
  delay(100); // 2400 BAUD is fairly slow -- a little delay helps keep the system from bogging down
  
} 

void scissorsEvent( String &theMessage ){  // its just a string

    Serial.println("\nReceived ");
    Serial.println(RFID_reader.getRaw());

    //data extraction from incoming message
    Serial.println("parsing message");
    newTag = RFID_reader.getString(0);

}
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Serial.begin(9600);
Serial.println();
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//  Scissors Example:  RFID.ino
//  Scissors used as an RFID tag reader 
//  updated 2024 (hex705)

//  Match the BAUD in .begin() call to the BAUD of your reader.
//  Set DELIMITER to -1
//  Set START_BYTE and END_BYTE to match tag structure.

/* circuit 
   vcc= 5V
   gnd = gnd
   s-out of reader to pin 0 (RX arduino UNO )
   sn (reader) is enable it must be LOW -- connect  to ground or control with pin (in this case 2)
*/

/* 
   indicators
   ironically -- a red LED is good on my reader -- a green led is bad
   -- when the enable pin is pulled LOW (down) teh LED goes red adn tags can be read
*/


// ************   NOTE -- upload challenges   **************
// in this care RFID is using UNO serial pins.
// these are connected to USB 
// !!!   you MUST disconnect the data line to UNO pin 0 to upload, then reconnect to read  !!!!
// ************


// Example developed by hex705 (Steve Daniels)
// github.com/hex705


#include <Scissors.h>

// https://www.luisllamas.es/en/esp32-uart/
// define pins for serial 2 -- not the USB cable which is JUST Serial
#define RXD2 16
#define TXD2 17

Scissors RFID_reader;
  
String newTag = "";
String oldTag ="";

int enablePin = 14;
  
  
void setup() {

  Serial.begin(9600);

  // this is the serial UART (port) for the RFID reader - Serial2 -- the 2 is important!
  Serial2.begin(2400, SERIAL_8N1, RXD2, TXD2);
  // attache scissors to the stream from RFID
  RFID_reader.begin(Serial2); 
   
   // scissors needs to have the package structure set to match RFID tags.
   // each tag send a message of form:
   // START_BYTE payload_of_length_10_bytes END_BYTE
     RFID_reader.setStartByte( 0x0A ); // 10 == start_byte
     RFID_reader.setEndByte  ( 0x0D ); // 13 == end_byte
     RFID_reader.setDelimiter( -1 );   // no delimiters 
   
   // The Scissors settings above could be replaced with the following
   // RFID_reader.begin(2400,10,13,-1); 

  pinMode(enablePin,OUTPUT);

  digitalWrite(enablePin,LOW); // enable LOW ! 
  Serial.println("rfid testing, setup complete");
} 


void loop () {

  RFID_reader.poll();  // check for messages

  if ( ! newTag.equals(oldTag) ) {
      Serial.println(newTag);                 // only print new tags that are different than last tag  
  } 
       
  oldTag = newTag;
       
  delay(100); // 2400 BAUD is fairly slow -- a little delay helps keep the system from bogging down
  
} 

void scissorsEvent( String &theMessage ){  // its just a string

    Serial.println("\nReceived ");
    Serial.println(RFID_reader.getRaw());

    //data extraction from incoming message
    Serial.println("parsing message");
    newTag = RFID_reader.getString(0);

}
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M = main

S = subCopy

MOSI (pronounced mossy) -- main out, sub in
MISO (pronounced meezo) -- main in, sub outCopy

// UNO settings - comment out the ESP below
#define SS_PIN 10 // (uno)
#define RST_PIN 9 // (uno)Copy

// ESP settings - comment out the UNO above
#define SS_PIN 23  // (esp)
#define RST_PIN 21 // (esp)Copy

/*

https://github.com/miguelbalboa/rfid/blob/master/src/MFRC522.h


 * --------------------------------------------------------------------------------------------------------------------
 * Example sketch/program showing how to read new NUID 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 the 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 type, and the NUID if a new card has been detected. 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
 * 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
 *
 * More pin layouts for other boards can be found here: https://github.com/miguelbalboa/rfid#pin-layout
 */

 /* for esp32 huzzah 32 from adafruit - tested 2024
 * works with huzzah
 * RST/Reset   RST          21           
 * SPI SS      SDA(SS)      23           
 * SPI MOSI    MOSI         18 
 * SPI MISO    MISO         19 
 * SPI SCK     SCK          5   
 */

#include <SPI.h>
#include <MFRC522.h>

// UNO settings - comment out the ESP below
#define SS_PIN 10 // (uno)
#define RST_PIN 9 // (uno)

// ESP settings - comment out the UNO above
//#define SS_PIN 23  // (esp)
//#define RST_PIN 21 // (esp)
 
MFRC522 rfid(SS_PIN, RST_PIN); // Instance of the class


// kind of tag the 522 can read -- code for this commented out -- but just in case ... 
MFRC522::PICC_Type compatableTagType = MFRC522::PICC_TYPE_MIFARE_1K;

// string to store incoming tag ID
String newTagID = "";
String oldTagID = "";

void setup() { 
  Serial.begin(9600);
  SPI.begin(); // Init SPI bus
  rfid.PCD_Init(); // Init MFRC522 
}
 
void loop() {

  readRC522(); // check the reader

  oldTagID = newTagID;
  newTagID = "";
}

void readRC522(){

  // Reset the loop if no new card present on the sensor/reader. This saves the entire process when idle.
  if ( ! rfid.PICC_IsNewCardPresent())
    return;

  // Verify if the NUID has been read
  if ( ! rfid.PICC_ReadCardSerial())
    return;

  // // Check t osee if tag is the Classic MIFARE type (1k)
  // Serial.print("Tag read, type: ");
  // MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak);
  // Serial.println(rfid.PICC_GetTypeName(piccType));

  // if (piccType != compatableTagType) {
  //   Serial.println(F("Your tag is not compatable with this reader"));
  //   return;
  // }

    // place new ID into a string for comparison and use 
    for (byte i = 0; i < 4; i++) {
     // nuidPICC[i] = rfid.uid.uidByte[i];
      newTagID+=rfid.uid.uidByte[i];
    }

  if (oldTagID != newTagID) {
    Serial.println(F("A new tag has been detected."));
    Serial.println(newTagID);
    Serial.println();
  }
  else {
    Serial.println(F("Card read previously."));
  }

  // Halt PICC
  rfid.PICC_HaltA();

  // Stop encryption on PCD
  rfid.PCD_StopCrypto1();

} // end read 
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