circuitpython/ports/nrf/boards/makerdiary_nrf52840_mdk_usb_dongle

MakerDiary NRF52840 MDK USB Dongle

Refer to The makerdiary Github repo or The nrf52840-mdk-usb-dongle wiki for more details about the device.

This is pretty much just the nRF52840 with a useful number of pins exposed for your pleasure along with one RGB LED and an onboard antenna in a USB stick form factor with room for headers on the sides.

Note that all three LEDs on this device are wired through sinks, not sources, so flip your boolean expectations when dealing with DigitalInOut or PWMOut on this device -- led.value = True or led.duty_cycle = 0xffff turns the LED off!

The onboard button is hard wired to the Reset pin so you cannot use it yourself.

Installing CircuitPython submodules

Before you can build, you will need to run the following commands once, which will install the submodules that are part of the CircuitPython ecosystem, and build the mpy-cross tool:

$ cd circuitpython
$ git submodule update --init
$ make -C mpy-cross

Note about bootloaders

While most Adafruit devices come with (or can easily be flashed with) an Adafruit-provided bootloader (supporting niceties like UF2 flashing), this board comes with one that supports DFU via nrfutil. If you ever need to restore the DFU bootloader via a SWD debugger, use the nRF52 open bootloader hex file.

Building and Flashing CircuitPython

$ cd ports/nrf

Build CircuitPython for the MDK USB Dongle

make BOARD=makerdiary_nrf52840_mdk_usb_dongle SD=s140 V=1 -j4 hex

This should produce a build-makerdiary_nrf52840_mdk_usb_dongle-s140/firmware.hex file.

Install nrfutil

You'll need to have nrfutil installed as appropriate for your system. As of 2019-01, nrfutil still requires Python 2.7... ugh!

Flash the nRF52 Radio Soft Device

Build a DFU package from the softdevice hex file and flash it:

nrfutil pkg generate --hw-version 52 --sd-req 0x00 --sd-id 0xAE --softdevice bluetooth/s140_nrf52_6.1.0/s140_nrf52_6.1.0_softdevice.hex dfu_sd140-6.1.0.zip
nrfutil dfu usb-serial -pkg dfu_sd140-6.1.0.zip -p /dev/tty.usbmodemABRACADBRA  # likely /dev/ttyACM0 on Linux

Note that the --sd=id 0xAE comes from the Nordic nRF52 manual for SoftDevice 6.1.0. When the SoftDevice is changed, read the Nordic manual to find the correct value and use it on all of the nrfutil pkg generate commands.

/dev/tty.usbmodem* is a macOS name. On Linux it'll likely be /dev/ttyACM*. On Windows probably a COM port.

Flash CircuitPython

Build a DFU package from the hex application file and flash it:

nrfutil pkg generate --sd-req 0xAE --application build-makerdiary_nrf52840_mdk_usb_dongle-s140/firmware.hex --hw-version 52 --application-version 1 dfu_circuitpython.zip
nrfutil dfu usb-serial -pkg dfu_circuitpython.zip -p /dev/tty.usbmodemABRACADBRA

I'm not sure if --application-version 1 is actually meaningful or required.

After this, your device should be up and running CircuitPython. When it resets, you'll see the CIRCUITPY USB filesystem and a new console usb modem serial port show up.

Adafruit CircuitPython 4.0.0-alpha.5-139-g10ceb6716 on 2019-01-14; MakerDiary nRF52840 MDK USB Dongle with nRF52840
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TODO items

• Update the Makefile to do the above DFU .zip building and nrfutil flashing.
• Create a UF2 bootloader for this. It is already a USB stick form factor, it deserves to behave like one.