NFC stops working

[T IJ]

Hello Devzone,

For my project I am using NFC and I am using the writeable NDEF message project as an example.

Everything is working except I have found one issue.

Whenever I receive the NFC_T4T_EVENT_FIELD_ON event and I get an interrupt that takes time to complete NFC stops working.

I can still read and write my device but the NFC_T4T_EVENT_NDEF_UPDATED is never triggered.

I use this event to process all incoming data.

This issue can be easily reproduced by adding the following code in the NFC_T4T_EVENT_FIELD_ON event

uint32_t temp = 100000;
while(--temp); // Simulate interrupt by "waiting" in event.

How can I solve this problem that the NFC_T4T_EVENT_NDEF_UPDATED  will be triggered if I receive an interrupt in the NFC_T4T_EVENT_FIELD_ON event?

[Simonr]

Hi

How are you handling the NFC_T4T_EVENT_FIELD_ON event in your application? What is this interrupt triggered here that takes X amount of time?

What SDK version are you using? Similar cases in the past has been solved by updating to a newer SDK version, as there were made some fixes to the T4T in SDK v17.0.2

Best regards,

Simon

[T IJ]

I am working with SDK17.0.2.

At first I had my devkit have its light turn on just as in the example.

This I've changed to a log plot that prints " NFC - Field On." 

I also have periodic interrupts generated by the app timer to gather some sensor data an drive some LED's.

In the NRF_T4T_EVENT_NDEF_UPDATE I have a second log that prints "NFC - Message Written."

What I've seen is that multiple times I get the two plots " NFC - Field On."  and "NFC - Message Written." 

After I've only received the " NFC - Field On."  event it stopped working. My NFC reader chip is able to read the UID from the nRF but as soon as it commits the RATS command I get a card time out event.