Adafruit
nRF52840 USB Key with TinyUF2 Bootloader - Bluetooth Low Energy
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 somethi...
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.
Each MDBT50Q-RX dongle comes pre-programmed with the TinyUF2 bootloader, which makes loading code onto it very easy (note that only the ones from Adafruit do this, its a special-order item). To enter the bootloader, hold down the dongle's button while inserting into USB. The button can be used in Arduino/CircuitPython as an input. There's also a single blue LED indicator. It's all very simple but we could see situations where perhaps this acts as a beacon, a OS-less BLE interface or bridge, or a compact development board for experimenting with the nRF52840.
The blue LED is connected to P1.13, set that pin to be an output and pull low to turn on the LED
The button is connected to P0.15, set that pin to be an input with an internal pullup - when pressed the pin will go low.
Of course the best way to program these chips is with the Nordic SDK. This chip also has some basic Arduino support, CircuitPython support, and is supported by MyNewt.
Jargon buster
Plain-language definitions for the technical terms used above.
- BLE
- BLE stands for Bluetooth Low Energy, a Bluetooth mode designed for lower power use and modern phone compatibility. It matters because BLE support can make the module easier to use with Apple devices and battery-powered projects, though it may behave differently from classic serial Bluetooth.
- Bootloader
- Small starter software on a microcontroller that lets new code be uploaded before the main program runs. Knowing how to enter bootloader mode matters when you need to program the board or recover it after a faulty sketch.
- CircuitPython
- A beginner-friendly version of Python designed to run directly on microcontroller boards. If a product supports CircuitPython, you can often program it by copying code files onto the board rather than setting up a more complex toolchain.
- LED
- A light-emitting diode is a small electronic component that lights up when current flows through it in the correct direction. In this kit, LEDs create the flashing effect, so polarity and correct soldering matter for the project to work.
- microcontroller
- A microcontroller is a small computer on a chip that runs your program and controls connected inputs and outputs. For this product, it is the part that reads buttons and sensors, drives the display and speaker, and communicates over Bluetooth.
- nRF52840
- The nRF52840 is a Nordic Semiconductor microcontroller commonly used in maker boards, especially where Bluetooth Low Energy is needed. Seeing it listed tells you the USB host software may support boards based on this chip.
- USB host
- A USB host is the side of a USB connection that controls attached devices, like a computer talking to a keyboard or flash drive. This matters because most microcontroller boards are normally USB devices, so adding USB host support lets them use common USB peripherals.
Find this product in
Brands
Connectivity
Microcontrollers
Related Tutorials
Free guides on learn.littlebird.com.au
