Grove NFC with Arduino Uno 3 not working

Products & Technology Grove
#1

Hi,
I have a Grove NFC v1.1 and Uno 3. I tried UART and when it didn’t work I cut the UART bridges and solder bridged the I2C pads as instructed, and still get the same error:

Didn't find PN53x board

With the UART I tried SoftwareUART as well on pins 2 and 3. Same error.

I am updating the code of course (the #if to pick the right serial type). I have even simplified the code just in case, for I2C:

#include <NfcAdapter.h>
#include <PN532/PN532/PN532.h>

//use I2C

#include <Wire.h>
#include <PN532/PN532_I2C/PN532_I2C.h>

PN532_I2C pn532_i2c(Wire);
NfcAdapter nfc = NfcAdapter(pn532_i2c);

void setup(void) {
    SERIAL.begin(9600);
    SERIAL.println("NDEF Reader");
    nfc.begin();
}

void loop(void) {
    SERIAL.println("\nScan a NFC tag\n");
    if (nfc.tagPresent()) {
        NfcTag tag = nfc.read();
        tag.print();
    }
    delay(5000);
}

And I have checked the solder bridges with an ohm meter, no connection on UART pins, good connection on I2C pins.

I have connected the Grove NFC using the Grove-to-breadboard-pin-male cable with the following connections to the UNO:

Grove | UNO
GND -> GND
VCC -> 3.3V
SLC -> SLC
SDA -> SDA

The only questionable connection is the 3.3V, which I guess could be 5V but in the documentation for the Grove NFC it is mentioned to run at 3.3V. I don’t dare try 5V as I don’t want to damage it.

Any help will be greatly appreciated.

#2

@Hamid_M There’s nothing wrong with the code.You need to make sure the hardware is connected correctly.

#3

Yep. The SLC and SDA pins are the opposite of how they appear in the solder bridges so I had them backwards. Its working now (albeit not as well as I had hoped, the performance of PN532 is very poor compared to ST25R3916 chip).