Multiple RFID readers connected to Arduino Uno

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1

Hy,
I have problems with multiple RFID(MFRC522) usage.
I use the MFRC522.h library from https://github.com/miguelbalboa/rfid, and I want to read 8 RFID modules with one Arduino Uno, but I have managed only 2!
I connect all the SPI pins, SS1 to pin10 and SS2 to pin2.
How can I get to read 8 RFID with one Arduino Uno?

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

#define RST_PIN         9          // Configurable, see typical pin layout above
#define SS_1_PIN        10         // Configurable, see typical pin layout above
#define SS_2_PIN        2         // Configurable, see typical pin layout above

//#define SS_3_PIN        10

#define LedPin          8
#define NR_OF_READERS  2

byte ssPins[] = {SS_1_PIN, SS_2_PIN};
int a=0;
int b=0;

MFRC522 mfrc522[NR_OF_READERS];   // Create MFRC522 instance.

/**
   * Initialize.
 */
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)
pinMode(LedPin,OUTPUT);
SPI.begin();        // Init SPI bus

for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
mfrc522[reader].PCD_Init(ssPins[reader], RST_PIN); // Init each MFRC522 card
}
}

/**
* Main loop.
   */
   void loop() {
   for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
   // Look for new cards


if (mfrc522[reader].PICC_IsNewCardPresent() && mfrc522[reader].PICC_ReadCardSerial()) {
  Serial.print(F("Reader: "));
  Serial.print(reader);
  // Show some details of the PICC (that is: the tag/card)
  Serial.print(F(" Card UID:"));
  dump_byte_array(mfrc522[reader].uid.uidByte, mfrc522[reader].uid.size);
  Serial.println();
 Serial.print(F("PICC type: "));
  MFRC522::PICC_Type piccType = mfrc522[reader].PICC_GetType(mfrc522[reader].uid.sak);
  Serial.println(mfrc522[reader].PICC_GetTypeName(piccType));
          if (mfrc522[reader].uid.uidByte[0] == 140 &
          mfrc522[reader].uid.uidByte[1] == 120 & 
          mfrc522[reader].uid.uidByte[2] == 34 & 
          mfrc522[reader].uid.uidByte[3] == 43 & 
          reader==0 ) {
          Serial.println(F("pirmā karte atrasta"));  
          a++; 
          }
            if (mfrc522[reader].uid.uidByte[0] != 140 &
          mfrc522[reader].uid.uidByte[1] != 120 & 
          mfrc522[reader].uid.uidByte[2] != 34 & 
          mfrc522[reader].uid.uidByte[3] != 43 & 
          reader==0 ) {
          Serial.println(F("pirmā karte nodzes"));  
          a=0; 
          }
          
         if (mfrc522[reader].uid.uidByte[0] == 5 &
          mfrc522[reader].uid.uidByte[1] == 233 & 
          mfrc522[reader].uid.uidByte[2] == 26 & 
          mfrc522[reader].uid.uidByte[3] == 43 & 
          reader==1 ) {
          Serial.println(F("otrā karte atrasta"));
          b++;   
          }
      if (mfrc522[reader].uid.uidByte[0] != 5 &
          mfrc522[reader].uid.uidByte[1] != 233 & 
          mfrc522[reader].uid.uidByte[2] != 26 & 
          mfrc522[reader].uid.uidByte[3] != 43 & 
          reader==1 ) {
          Serial.println(F("otrā karte nodzēs"));
          b=0;   
          }
          
          if (mfrc522[reader].uid.uidByte[0] == 140 &
          mfrc522[reader].uid.uidByte[1] == 120 & 
          mfrc522[reader].uid.uidByte[2] == 34 & 
          mfrc522[reader].uid.uidByte[3] == 43 & 
          reader==1 ) {
            Serial.println(F("otrā karte nodzēs"));
          b=0;   
          }
          
                   if (mfrc522[reader].uid.uidByte[0] == 5 &
          mfrc522[reader].uid.uidByte[1] == 233 & 
          mfrc522[reader].uid.uidByte[2] == 26 & 
          mfrc522[reader].uid.uidByte[3] == 43 & 
         reader==0 ) {
          Serial.println(F("pirmā karte nodzes"));  
          a=0; 
          }
Serial.println();

  // Halt PICC
  mfrc522[reader].PICC_HaltA();
  // Stop encryption on PCD
  mfrc522[reader].PCD_StopCrypto1();
  } //if (mfrc522[reader].PICC_IsNewC
  } //for(uint8_t reader
  if (a>0 & b>0)
  {
  digitalWrite(LedPin,HIGH);
   delay(1000);
  digitalWrite(LedPin,LOW); 
  }



}

/**
* Helper routine to dump a byte array as hex values to Serial.
*/
void dump_byte_array(byte *buffer, byte bufferSize) {
for (byte i = 0; i < bufferSize; i++) {
Serial.print(buffer[i] < 0x10 ? " 0" : " ");
Serial.print(buffer[i], HEX);
 }
}
2

Hey there, welcome to the Particle community!

Considering youā€™re talking about the Arduino Uno, Iā€™d like to mention that these forums are actually meant for the Particle devices. Though they share a lot of similarities with Arduinos, there are also a fair share of differences. With that in mind, itā€™s easier to find support on an Arduino forum I think, since theyā€™re more prone to have encountered things like these before.
You could always get a Particle device to play around with, theyā€™re an awful lot of fun :wink:

Best of luck!

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