Grove NFC + Wio Terminal question on SoftwareSerial mode

I’m shifting several lesson of a course from Arduino MKR 1010 to Wio Terminal.
I’m encountered a problem in the use of Grove NFC.

I’m using it as UART (as it’s being sold), hence using software serial mode in order to attach the grove NFC to the right plug on the Wio.

I’ve declared the pins like “D0, D1” or “D1, D0”, or BCM27, BCM22 and vice versa, but nothing is read (nor printed on the serial).
Any help in the use of this grove module with Wio the easy way? (I assume one could hook it in the back GPIOs, but since this is an entry level course I’d rather sthik on those two ports)

Any help appreciated!

#elif 1  // use software serial

    #include <PN532/PN532_SWHSU/PN532_SWHSU.h>
    #include "SoftwareSerial.h"
    SoftwareSerial SWSerial(BCM27, BCM22);
    PN532_SWHSU pn532swhsu(SWSerial);
    NfcAdapter nfc(pn532swhsu);

A simple example is given for your reference.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(0, 1); // RX, TX

void setup()
  while (!Serial) {

  Serial.println("Goodnight moon!");

  mySerial.println("Hello, world?");

void loop()
  if (mySerial.available())
  if (Serial.available())
1 Like

I don’t doubt the Sowftare Serial library is not behaving as expected.

I’ve connected the NFC in the back, declaring other pins, but anything is read on the software serial.

Then I hooked it up to the Hardware Serial (always inverting the pins, in case I confused them - couldn’t find in the documentation which is TX and which is RX) but no luck in both cases.

So I thought to test the I2C. As stated earlier, I use this for teaching, so I happen to have several NFC readers laying around. Cutted the Serial, soldered the I2C. Edited the code all conditions to 0, leaving the else to I2C.

#if 0 // use SPI
    #include <SPI.h>
    #include <PN532/PN532_SPI/PN532_SPI.h>
    PN532_SPI pn532spi(SPI, 9);
    NfcAdapter nfc = NfcAdapter(pn532spi);
#elif 0 // use hardware serial

    #include <PN532/PN532_HSU/PN532_HSU.h>
    PN532_HSU pn532hsu(Serial1);
    NfcAdapter nfc(pn532hsu);
#elif 0  // use software serial

    #include <PN532/PN532_SWHSU/PN532_SWHSU.h>
    #include "SoftwareSerial.h"
    SoftwareSerial SWSerial(BCM2, BCM3);
    PN532_SWHSU pn532swhsu(SWSerial);
    NfcAdapter nfc(pn532swhsu);
#else //use I2C

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

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

Also in this case I don’t see anything in the Serial monitor.
I’m testing this both with Arduino IDE 1.8.15 and Arduino IDE 2. The Wio Terminal I’m using have been update in its wireless core, but I think this is not influecing this at all.

Do you have any advices?
From my perspective, the problem can only be the library, but I checked twice it to be yours Seeed Arduino NFC Library and PN532 Library

The NFC module are version v 1.1

Sorry to confirm with you that I did not misunderstand. You can connect the NFC to the pin behind the wio terminal and it works fine, right? Is it the location of the hardware serial port?

Mmm. No. Unfortunately I am having trouble with any setup: hardware serial, software serial and i2c.
Do you confirm this library has been tested and ported to samd51?

What can I do to debug this?

I will take the time to test it, please wait.

Any updated from your side?
(With the help of Don) I can confirm you the software serial mode is not working to me, while the hardware serial one is (on pin 8 and 10 on the back of the Wio).

No luck with the grove connector :frowning:
Any help appreciated.

thanks in advance