nRF52840 USB Dongle Nordic Semiconductor nRF52840 USB Dongle is a small wireless hardware device with nRF Connect for Desktop based on the nRF52840 System-on-Chip (SoC). The nRF52840 dongle provides support for programming the device and communication through USB. This dongle incorporates a user-programmable RGB LED, a user-programmable button, and 15 General Purpose Input / Output (GPIO) accessible from castellated solder points along the edge. Nordic nRF52840 dongle is updatable through USB Device Firmware Update (DFU). This dongle is suitable for BLUETOOTH® low energy (BLE), BLUETOOTH mesh, Thread, ZigBee, ANT, and 2.4GHz proprietary applications using nRF52840.