nRF DFU

pc-nrf-dfu-cs is a C# module which provides DFU (Device Firmware Upgrade) via Serial UART / USB CDC ACM transport for Nordic devices.

This module is multi-targeted .NET library and was adapted from pc-nrf-dfu-js and is designed to provide DFU capabilities to .NET applications.

The following devices are supported:

• USB SDFU:
  • PCA10056 nRF52840 Development Kit
  • PCA10059 nRF52840 Dongle
  • Custom nRF boards using Nordic SDK 15.x DFU application/bootloader libraries
    • Tested using custom firmware on Particle Xenon (Nordic SDK version 15.3.0)

Installation

$ Install-Package Nordic.nRF.DFU

Dependency requirements

Nuget Packages (listed versions are as tested)

• Google.Protobuf (3.10.1)
• Newtonsoft.Json (12.0.2)
• System.IO.Compression.ZipFile (4.3.0)
• System.IO.Ports (4.6.0)

USB SDFU devices

Windows

In order to access Nordic USB devices on Windows, specific device drivers must be installed. The device drivers are automatically installed by the nRF Connect installer, starting from version 2.4. The drivers can also be found here.

Linux (untested, should work under Mono)

Linux requires correct permissions to access these devices. For this purpose please install udev rules from nrf-udev repository, follow instructions there.

Usage

using Nordic.nRF.DFU
...

// Create DfuUpdates
var updates = await DfuUpdates.FromZipFile(firmwarePath);

// Create DfuTransportSerial
var serialTransport = new DfuTransportSerial(portName, 16);
OR
var serialPort = new SerialPort(...) { ... constructed as needed ... };
var serialTransport = new DfuTransportSerial(serialPort, 16);

// Create DfuOperation
var dfu = new DfuOperation(updates, serialTransport);

// Start dfu
await dfu.Start(true);

USB SDFU

PCA10059 is a nRF52840 dongle which does not have a JLink debugger, so the USB device that the operating system sees depends on the firmware that is currently running on the Nordic chip.

This can be either a bootloader or an application firmware.

Bootloader mode

The pre-programmed bootloader provides a USB device with vendor ID 0x1915 and product ID 0x521f. This device has a USB CDC ACM (serialport) interface which handles the DFU operation. In case you need to manually trigger the bootloader, press the RESET button on the dongle.

Application mode

The dongle will be in application mode if it is plugged in and is programmed with a valid application. It will also switch to application mode after a successful DFU operation.

In application mode the USB device visible to the OS depends on the application firmware. For further documentation please refer to the Nordic SDK.

In application mode it is expected that the visible USB device to the OS has a DFU trigger interface. This interface provides a semver string which identifies the application firmware currently running. If the semver doesn't match the expected value, the device will be reset into bootloader mode.

Changing between bootloader and application also implies that the USB device is detached and attached, so there is an underlying functionality based on nrf-device-lister which looks for the newly attached USB device and tries to match by its port name (eg. COM14).

Development

Build

The project uses FAKE, so the following command is needed to run the build:

Windows
$fake build

Linux
>./fake.sh build

Test

The project comes with a test console application in the test directory, which expects a serial port name and application package to be supplied:

Windows
$dotnet DFUConsole.dll COM14 test_package_0.0.1.zip

Linux
>mono dotnet DFUConsole.dll /dev/com1 test_package_0.0.1.zip