CircuitPython on MakerDiary NRF52840

While I really like the ESP32 chip, I wanted to play with the NRF52840 which is a pretty neat chip!

So I bought MakerDiary NRF52840 Usb Dongle which doesn't cost too much ($12.99)https://store.makerdiary.com/products/nrf52840-mdk-usb-dongle

Here is some characteristics :

• Bluetooth Low Energy
• Power efficient
• It's really small
• NFC tag
• RGB Led
• And most of all compatible with CircuitPython (thanks to gpshead )

Source: https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52840

Let's see how to install CircuitPython, then we test it with a small example to control the RGB Led using BLE

Documentation

Install NRF Connect

First we need NRF Connect, we will use this software to upload CircuitPython on our board.

You can download it here : https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-desktop

Click Install on Programmer

Put the board in bootloader mode

Press the RESET Buttonwhile plugging the board, you should see a RED led pulsing

You can, now, connect your board to NRF Connect Programmer

Download Adafruit NRF52 Bootloader and CircuitPython

We need 2 hex files to install CircuitPython

• A bootloader, which will make our board visible as a USB drive
• CircuitPython to interpret our python code

Download mdk_nrf52840_dongle_bootloader-X.X.X_sXXX_X.X.X.hex here :https://github.com/adafruit/Adafruit_nRF52_Bootloader/releases

Then download CircuitPython here : https://circuitpython.org/board/makerdiary_nrf52840_mdk_usb_dongle/

BLE Support is only available on CircuitPython 5.0.0 ! Don't install the current stable release (4.1.2).

Upload Hex files

In Programmer, Add the 2 Hex Files it should look like this:

Unplug and replug your board, you should see a USB Drive

Congratulations you can now code using CircuitPython !

You won't be able to access your board with NRF Connect now, If you need to upload a new program, just press reset.

Testing BLE communication

One cool thing, with CircuitPython is that we just have to drag and drop file to make it works!

So let's try that, download this program and copy it into your boardhttps://github.com/maditnerd/makerdiary_circuitpython_test/archive/master.zip

The LED should turn white!

Control the RGB LED

You should also be able to control the LED using your phone.

• Download Adafruit Bluefruit LE Connect on your app store

• Connect to CIRCUITPY****
• Go to Controller / Color Picker and try to change the color!

Code your own program

You can now follow Adafruit Tutorials, code made for Adafruit NRF52840 should works fine!

• CircuitPython tutorial : https://learn.adafruit.com/welcome-to-circuitpython
• Bluetooth LE tutorial : https://learn.adafruit.com/circuitpython-nrf52840
• Libraries : https://circuitpython.org/libraries

You can use whatever software to code, but https://codewith.mu/ is recommanded.

Each times you save code.py, the code will restart, check the Serial Port for errors and debug information.