NFC not working on payment readers

RE: NFC not working on payment readers

Jørgen Holmefjord — Fri, 30 Jun 2017 12:57:27 GMT

Hi,

The NFCT peripheral will trigger an event if a field is detected when sensing mode is enabled. This short code shows how to enable sensing and interrupt for FIELDDETECTED event:

#include <nrf.h>

// This IRQ handler will trigger when NFC field is detected
void NFCT_IRQHandler(void)
{
  if (NRF_NFCT->EVENTS_FIELDDETECTED == 1)
  {
    NRF_NFCT->EVENTS_FIELDDETECTED = 0;
    //Field detected
  }
}

int main(void)
{
    //Enable interrupt for FIELDDETECT Event
    NRF_NFCT->INTENSET = NFCT_INTENSET_FIELDDETECTED_Enabled << NFCT_INTENSET_FIELDDETECTED_Pos;
    
    //Register interrupt for NFCT module
    NVIC_EnableIRQ(NFCT_IRQn);
    
    //Start sensing 
    NRF_NFCT->TASKS_SENSE = 1;
    while(1)
    {
        // do nothing
    }
}

Best regards,

Jørgen

RE: NFC not working on payment readers

kian79 — Fri, 30 Jun 2017 10:27:19 GMT

I am still unable to figure out the problem. The wake_on_nfc example does not trigger any field sense event. There is not a section of code that does that, as compared to the codes for the other 2 examples. Anyone else can any other comments?

RE: NFC not working on payment readers

endnode — Fri, 30 Jun 2017 05:37:10 GMT

Field sense (detect) event should be available any time, you don't need to set the chip to POWER OFF mode. There is no SDK example which would work directly on top of NFCT peripheral, probably because the primary support is to NDEF TAG type 2 and 4 "libraries". So it's on you but it should e fairly easy from what I see.

RE: NFC not working on payment readers

kian79 — Fri, 30 Jun 2017 04:46:42 GMT

The wake_on_nfc exmaple requires the MCU to be asleep and the presence of the NFC field is used to wake up the MCU.

But in my application, I need the MCU to be performing some other task at the same time, and when a NFC field is detected, a different task is performed. So I don't think I can adapt the wake_on_nfc example to my application. Or are you able to advise on how I can modify this code for my application?

RE: NFC not working on payment readers

endnode — Fri, 30 Jun 2017 01:05:42 GMT

OK, so you need to only detect presence of ISO14443-A field and you are saying that wake_on_nfc works. So is there any problem?

RE: NFC not working on payment readers

kian79 — Fri, 30 Jun 2017 00:43:58 GMT

Hi Endnode,

Thanks for the reply. I actually just need to detect the presence of an NFC field and nothing else. There is no exchange of message or communication need.

RE: NFC not working on payment readers

endnode — Thu, 29 Jun 2017 14:08:09 GMT

What do you expect payment reader doing with totally non-payment NFC app? Providing field and doing anti-collision is maximum you will get.