Interrupt when card removed PN512

Projects Programming
1

Hello,

I'm working on a project involving four PN512s. I manage to get an interrupt when a card is detected but I don't understand how to get one when the card is removed.

Can you help me with that ?

Here my code:

#include <SPI.h>
#include <PN512.h>
#include "FastLED.h"

/*------------------RFID-------------------*/
#define NFC_RST 16

#define NFC_SS_1 17
#define NFC_SS_2 21
#define NFC_SS_3 22
#define NFC_SS_4 25

#define NFC_MOSI 23
#define NFC_MISO 19
#define NFC_SCK 18

#define IRQ_1 36
#define IRQ_2 39
#define IRQ_3 34
#define IRQ_4 35

#define NB_OF_READERS 4

PN512 readers[NB_OF_READERS];

/*tableau des pins de selection d'esclave*/
byte ssPins[] = { NFC_SS_1, NFC_SS_2, NFC_SS_3, NFC_SS_4 };

/*tableau des pins IRQ*/
byte irqPins[] = { IRQ_1, IRQ_2, IRQ_3, IRQ_4 };

/*état des evenements sur les lecteurs*/
volatile bool newCards[] = { false, false, false, false };

/*------------------!RFID-------------------*/

/*------------------RUBAN------------------*/

/*nombre de LEDs sur un ruban*/
#define NB_LED_STRIPS 25

/*pins de controle des rubans*/
#define STRIP_1_PIN 26
#define STRIP_2_PIN 27
#define STRIP_3_PIN 32
#define STRIP_4_PIN 33

/*nombre de rubans*/
#define NB_OF_STRIPS 4

/*tableau des pins de controle des rubans*/
byte stripsPins[] = { STRIP_1_PIN, STRIP_2_PIN, STRIP_3_PIN, STRIP_4_PIN };

/*tableau des ruban*/
CRGB strips[NB_OF_STRIPS][NB_LED_STRIPS];

/*position d'animation de chaque ruban*/
byte animatePositions[] = { 0, 0, 0, 0 };

/*index de la LED témoin de fonctionnement*/
#define STANDBY_LED 13

/*couleur d'animation du ruban*/
CRGB animationColorP1[] = { CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green };
CRGB animationColorP2[] = { CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green };

/*es qu'il faut animer un chenillard bi directionnel, classement par ruban*/
boolean mustAnimateBiDirectional[] = { false, false, false, false };

/*------------------!RUBAN------------------*/

volatile bool bNewInt = false;
void setup() {
  Serial.begin(9600);
  delay(1000);
  /*------------------RFID-------------------*/
  //remettre à 0 les lecteurs
  pinMode(NFC_RST, OUTPUT);
  nfcReset();

  //démarrer la communication avec les lecteurs
  SPI.begin(NFC_SCK, NFC_MISO, NFC_MOSI);

  for (byte i = 0; i < NB_OF_READERS; i++) {
    //interdire à la bibliotheque l'utilisation du reset
    readers[i] = PN512(ssPins[i], UINT8_MAX);

    //initialiser le lecteur
    readers[i].PCD_Init();

    //définir le gain de l'antenne
    readers[i].PCD_SetAntennaGain(PN512::RxGain_33dB);

    //activer l'événement sur la présence d'une nouvelle carte
    pinMode(irqPins[i], INPUT_PULLUP);
    readers[i].PCD_WriteRegister(readers[i].ComIEnReg, 0b10100000);
    newCards[i] = false;
  }

  attachInterrupt(irqPins[0], irq0, FALLING);
  attachInterrupt(irqPins[1], irq1, FALLING);
  attachInterrupt(irqPins[2], irq2, FALLING);
  attachInterrupt(irqPins[3], irq3, FALLING);

  /*------------------!RFID-------------------*/

  /*------------------RUBAN-------------------*/
  FastLED.addLeds<NEOPIXEL, STRIP_1_PIN>(strips[0], NB_LED_STRIPS);
  FastLED.addLeds<NEOPIXEL, STRIP_2_PIN>(strips[1], NB_LED_STRIPS);
  FastLED.addLeds<NEOPIXEL, STRIP_3_PIN>(strips[2], NB_LED_STRIPS);
  FastLED.addLeds<NEOPIXEL, STRIP_4_PIN>(strips[3], NB_LED_STRIPS);
  /*------------------!RUBAN-------------------*/
}

void irq0() {
  newCards[0] = true;
}
void irq1() {
  newCards[1] = true;
}
void irq2() {
  newCards[2] = true;
}
void irq3() {
  newCards[3] = true;
}

void nfcReset() {
  digitalWrite(NFC_RST, LOW);
  delay(100);
  digitalWrite(NFC_RST, HIGH);
  delay(100);
}

char dataOut[256];
char dataLine[50];
void loop() {
  delay(40);

  for (byte i = 0; i < NB_OF_READERS; i++) {
    if (newCards[i]) {
      PN512 reader = readers[i];
      reader.PICC_ReadCardSerial();
      Serial.print(i);
      printHex(reader.uid.uidByte, reader.uid.size);
      clearInt(reader);
      reader.PICC_HaltA();
      newCards[i] = false;
    }
    activateRec(readers[i]);
  }
  delay(100);
}

/*
 * The function sending to the MFRC522 the needed commands to activate the reception
 */
void activateRec(PN512 reader) {
  reader.PCD_WriteRegister(reader.FIFODataReg, reader.PICC_CMD_REQA);
  reader.PCD_WriteRegister(reader.CommandReg, reader.PCD_Transceive);
  reader.PCD_WriteRegister(reader.BitFramingReg, 0x87);
}

/*
 * The function to clear the pending interrupt bits after interrupt serving routine
 */
void clearInt(PN512 reader) {
  reader.PCD_WriteRegister(reader.ComIrqReg, 0x7F);
}

void printHex(byte *buffer, byte bufferSize) {
  for (byte i = 0; i < bufferSize; i++) {
    Serial.print(buffer[i] < 0x10 ? " 0" : " ");
    Serial.print(buffer[i], HEX);
  }
  Serial.println("");
}
2

Why do you need an interrupt? You're scanning through the 'newCards[]' array on every pass through the loop() function. Why don't you instead use that for() loop to do a digitalRead() of each of the pins?

3

I am only at the beginning of my code, in the future I will have other actions in parallel.
Isn't it cleaner to make an interrupt rather than to interrogate the PN512 each time?

4

Not really. You're not able to do anything about it until you check the 'newCards[]' array in loop() anyway.

If you write proper non-blocking code that won't be an issue. And if you don't, the interrupt won't help because your checking of 'newCards[]' will be blocked.

5

Now I understand.
I will do like that !

Thank you.

6

Hello, can you share me a tutorial using module PN512 with any card NFC? example simple such as read and write data on Card. thanks you so much.

7

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