Clarification of LOCKDETECT flag of NFCT peripheral

[Remo]

Hi

I'm using the NFCT peripheral of the nRF52832 Rev. 1.

What is the intention of the LOCKDETECT field in the FIELDPRESENT register? I don't understand the description "Indicates if the low level has locked to the field".

Many thanks in advance.

Best regards

[Andreas]

Hi,

 

This indicates that the carrier frequency is correct and stable, it can e.g. be used to verify if a detected field is a valid NFC field or not. 1 = Locked means the field is valid.

 

Best regards,

Andreas

[Remo]

Thank you for the fast answer.

Do I have to respect this flag in my application? Is this flag still of importance when I've received the SELECTED event (NFC Auto collision resolution successfully completed)?

Best regards

Remo

[Andreas]

Hi,

 

Our NFC stack should check this, if you are using that you should not need to pay any attention to it. If you are making your own stack you might want to check it, it will probably only be interesting if you risk entering the Active state if a non-valid field is present.

 

Best regards,

Andreas

[Remo]

Hi Andreas

I've one last question. Is the FIELDDETECTED event generated due to the FIELDPRESENT flag or the LOCKDETECT flag?

[Andreas]

Hi,

 

EVENTS_FIELDDETECTED sets FIELDPRESENT.FIELDPRESENT. If there is lock, FIELDPRESENT.LOCKDETECT will be set.

 

Best regards,

Andreas