The NFC function will perform well when we use the “Seeed nRF52 mbed-enabled Boards Library”.
I managed to replicate the Arduino example code in the Wiki using the “Seeed nRF52 mbed-enabled Boards Library” as stated and both antennas below:
Both worked right just after soldering without further circuit tuning. Later, I added two 43 pF tuning caps from each NFC pad to GND to further enhance the interrogation distance for the TAOGLAS FXR.07.A.DG.
The ~40 pF cap value was calculated from subsection “6.14.10 NFCT antenna recommendations” in nRF52840 MCU product specification datasheet.
