Nordic NRF52840-DK Development Board

Combining Bluetooth 5 compliant, ANT, and IEEE 802.15.4 2.4 GHz multiprotocol radio.
On-chip NFC tag.
On-chip USB 2.0 (Full speed) device controller.
ARM® Cortex®-M4F processor optimized for ultra-low power operation.
ARM® TrustZone® CryptoCell-310 cryptographic accelerator.
1 MB FLASH.
256 kB RAM.