nRF52840 USB Key with TinyUF2 Bootloader - Bluetooth Low Energy [MDBT50Q-RX] : ID 5199 : $15.95 : Adafruit Industries, Unique & fun DIY electronics and kits

Adafruit Industries, Unique & fun DIY electronics and kits nRF52840 USB Key with TinyUF2 Bootloader - Bluetooth Low Energy [MDBT50Q-RX] : ID 5199 - This USB dongle/key type thing is a little unusual - it isn't a BLE adapter that you plug into a computer to add wireless capability. (If you do want something like that, our Bluetooth 4.0 USB Module will do the job nicely.) Instead, this is basically a minimal nRF52840 wireless microcontroller
This USB dongle/key type thing is a little unusual - it isn't a BLE adapter that you plug into a computer to add wireless capability. (If you do want something like that, our Bluetooth 4.0 USB Module will do the job nicely.) Instead, this is basically a minimal nRF52840 wireless microcontroller dev board on a stick. You can program it in Arduino or CircuitPython and it's completely standalone. This could be useful for some situations where you want to have a standalone BLE device that communicates with a USB host but without dealing with the operating system's BLE stack.

nRF52840 Micro Dev Kit USB Dongle : Electronics