XIAO nRF52840 NFC Antenna Insights

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.


Hi there,
Excellent Job on this, I’m certain there isn’t any good info on the topic like this post.
Thank you for the R & D. :slight_smile:
it Should really help and demonstrate this NFC area of Xiao.
GL :slight_smile: PJ