I have a Elechouse PN532 module (bought here - https://robu.in/product/pn532-nfc-rfid-read-write-module-v3-kit/). When I try to use to it with I2C and connect it to my ESP32 (DOIT ESP32 DEV KIT V1, 30 pin version), the PN532 gets detected but it doesn't detect when a card or token shown to it. When I try the exact same code with Arduino Uno with I2C, it works flawlessly. Below are the connections for both boards, the code, the output and actual connection picture (since some said wire position matters for PN532).
Connections
- ESP32
ESP32 | PN532 |
---|---|
GPIO 22 | SCL |
GPIO 21 | SDA |
3.3V | VCC |
GND | GND |
- Arduino Uno
Uno | PN532 |
---|---|
A5 | SCL |
A4 | SDA |
3.3V | VCC |
GND | GND |
The code
#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
#include <NfcAdapter.h>
PN532_I2C pn532i2c(Wire);
PN532 nfc(pn532i2c);
void setup(void) {
Serial.begin(115200);
//Wire.begin(21, 22); //used this line only when connected with ESP32
Serial.println("Hello!");
pn532i2c.wakeup(); //delays 500ms
nfc.begin();
uint32_t versiondata = nfc.getFirmwareVersion();
if (! versiondata) {
Serial.print("Didn't find PN53x board");
while (1); // halt
}
// Got ok data, print it out!
Serial.print("Found chip PN5"); Serial.println((versiondata>>24) & 0xFF, HEX);
Serial.print("Firmware ver. "); Serial.print((versiondata>>16) & 0xFF, DEC);
Serial.print('.'); Serial.println((versiondata>>8) & 0xFF, DEC);
// Set the max number of retry attempts to read from a card
// This prevents us from waiting forever for a card, which is
// the default behaviour of the PN532.
nfc.setPassiveActivationRetries(0xFF);
// configure board to read RFID tags
nfc.SAMConfig();
Serial.println("Waiting for an ISO14443A card");
}
void loop(void) {
boolean success;
uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 }; // Buffer to store the returned UID
uint8_t uidLength; // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
// Wait for an ISO14443A type cards (Mifare, etc.). When one is found
// 'uid' will be populated with the UID, and uidLength will indicate
// if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &uid[0], &uidLength);
if (success) {
Serial.println("Found a card!");
Serial.print("UID Length: ");Serial.print(uidLength, DEC);Serial.println(" bytes");
Serial.print("UID Value: ");
for (uint8_t i=0; i < uidLength; i++)
{
Serial.print(" 0x");Serial.print(uid[i], HEX);
}
Serial.println("");
// Wait 1 second before continuing
delay(1000);
}
else
{
// PN532 probably timed out waiting for a card
Serial.println("Timed out waiting for a card");
}
}
Output
Connection Placements
Also, the configuration of ESP32 in Arduino IDE