NFC (Near-Field Communication) is typically used to communicate small amounts of data to a mobile app in very close range, within a few inches.
Particle Gen 3 devices (Argon, Boron, B Series SoM, and TrackerSoM) only support emulating an NFC tag. They cannot locate or communicate with tags themselves, or support protocols such as for NFC payments.
A separate antenna is required. NFC uses the unlicensed 13.56 MHz band, and requires a special loop antenna for electromagnetic induction. On the Argon, Boron, and Xenon, the NFC antenna connects to a U.FL connector on the bottom of the board, directly underneath the USB connector. The Tracker One includes an NFC antenna within the sealed enclosure.
NFC is supported in Device OS 1.3.1 and later. NFC support was in beta test in Device OS 1.3.0. It is not available in earlier Device OS versions.
Gen 2 Devices (E Series, Electron, Photon, and P2; does not include E404X):
The P2, Photon 2, and Gen 2 devices (Photon, P1, Electron, E Series) do not support NFC.