Arduino detects PN532 chip but doesn't read any nfc tags

Projects General Guidance
1

I have a pn532 reader connected to an arduino clone. It is finding the chip and firmware version 1.6 but it won't read any tags.

connections are fine I already triple checked them and otherwise it wouldn't detect the chip as well.

Code is the following:

    // for SPI Communication
#include <SPI.h>
#include <PN532_SPI.h>
#include <PN532.h>
#include <NfcAdapter.h>
PN532_SPI interface(SPI, 10); // create a PN532 SPI interface with the SPI CS terminal located at digital pin 10
NfcAdapter nfc = NfcAdapter(interface); // create an NFC adapter object
String tagId = "None";
 
void setup(void) 
{
 Serial.begin(115200);
 Serial.println("System initialized");
 nfc.begin();
}
 
void loop() 
{
 readNFC();
}
 
void readNFC() 
{
 if (nfc.tagPresent())
 {
   NfcTag tag = nfc.read();
   tag.print();
   tagId = tag.getUidString();
 }
 delay(500);
}

I have tried a bankpass nfc card, small nfc circle's but seems like nothing works.

2

As far as I've got it there are different kinds of tags, working differently.
What type does the reader need? The datasheet tells that. It could be that the test cards You used are not of the proper type.

3

I tried testing it again and with 1 reader it is detecting it but with multiple it won't. It's hooked up to an external 5v power supply as well. I have a feeling it might be because of the arduino clone. I've ordered some OEM ones and gonna see if that works

4

? Multiple tags, several at the same time?

Good. Is the external GND connected to controller GND?

I'm using plenty of UNO clones without trouble but it's possible You've got bad clones.

5

multiple readers, Mosi Miso and sck connected and each their own SS. Gnd is connected from arduino to ext power supply. Gonna test it on an esp in a min and let you know.

6

Step back and make a one reader setup work. Then a schematics for the multi reader setup is interesting.

7

Problem was with the pn532 readers. I ordered some new ones from a different vendor and now it works perfectly with 4 readers