Programming the New Nordic Chip NRF52840, and USB Dongle Board PCA10059 Featuring it

Recently Nordic released a new board/dongle featuring their new microcontroller NRF52840. Although this board is not feature rich, like a full development kit, it still provides enough periphery for some basics, like blinky example and button example. There is also a possibility to do USB development because the board comes with a giant USB connector which makes it very portable, very simple to get started, and the most important thing, looks really nice 🙂 .

Of course the PCA10059 board has an on-board antenna which can be used for, among other things, Bluetooth. This makes the board great for Bluetooth development, especially if you need to have multiple boards interconnect with one another. You can just plug in as many as you need to USB ports, program them, and watch what happens. This is mostly what I’ll be doing with them.

Programming the PCA10059 USB dongle board

Programming of the board can be done through a USB interface, which is the most convenient way to program it in my opinion. Just to mention that there is also a 10-pin tag connect interface that can be used for programming, but we won’t be discussing that here.

In order to be able to program the PCA10059 board through USB, some sort of bootloader has to be used. Nordic provides such a bootloader on every PCA10059 board so we don’t have to worry about it.

General memory layout

The above image shows how the flash memory will generally look like. It can be seen that softdevice(SD) occupies the bottom part of flash pool, from address 0x1000 to somewhere around 0x26000. Start address will probably always be the same, but the end address could change with new revisions of softdevice. After softdevice comes the application part of the memory. The application can potentially occupy all of the empty space all the way up to the bootloader. Bootloader starts at 0xE0000 and consumes the rest of the available flash memory above this address. Bootloader part is always in the memory, but softdevice doesn’t have to be. If application doesn’t use any of the softdevice functionality, then softdevice can be omitted. More on this later.

PC side of things

Bear in mind that all of this is tested on MS Windows 10, with powershell(PS). It should work on other OSes, but I can’t give any guarantees.

With that out of the way, there are, according to Nordic, two ways to program the PCA10059 board. GUI or CLI. GUI way is by using the nRF Connect for Desktop app. CLI way is by using the nrfutil tool. Unfortunately I wasn’t able to make nRF Connect for Desktop work, so we will be using the CLI. However Nordic states that driver for PCA1059 board comes with nRF Connect for Desktop, so you will probably have to install that anyway.

Now lets install nrfutil tool. It is a python package that works only with python 2.7. Make sure you install it for python 2.7 and not for python 3. If you don’t have python, install it. You can find it here. Now check if pip is available, and check where is it:

pip -V
or as in my case
pip2 -V

If you are on windows output should be something like:

pip 9.0.1 from d:\python27\lib\site-packages (python 2.7)

And if pip command is not from python 2 folder, it will look something like:

pip 9.0.3 from d:\python36\lib\site-packages (python 3.6)

You can see either by the folder or by text in parentheses for which python version your pip command will install packages. If you don’t know what is the command to run the correct pip, you can just cd into python 2 directory and start pip from there like this:

cd d:/python27/Scripts
./pip.exe -V

If in folder run the following command, and if not just replace ./pip.exe with your pip command:

./pip.exe install nrfutil

Check if nrfutil got installed:

nrfutil --help

Now that everything is setup we are ready to start programming our board!

Downloading a simple blinky example to PCA10059 board

We will now finally download a blinky example .hex file from SDK to our board. If you have SDK you can go and find blinky example .hex file there, or just use this one:

Unzip this file and open a terminal window in a directory where you downloaded it. Type the following in terminal:

nrfutil pkg generate --hw-version 52 --sd-req 0x00 --application-version 1 --application .\blinky_pca10059_mbr.hex zip.zip

This will create zip.zip file in the folder you are currently in. You will probably get a big warning in your terminal 😀 . That is because we are not using keys to encrypt this newly generated .zip , and potentially someone could tamper with our precious .hex . We are currently not worried about that, but if you are going to use this in production, you should think about using keys to encrypt this .zip . We are not going to cover that here.

We will not go into detail about the options, just in short:

• hw-version depends on the microcontroller that is on board
• sd-req is the code for expected softdevice on board. This information was really hard to find, you can put 0x00 to basically say that you don’t care about this parameter
• application-version is any number you want
• application is the .hex file containing your program, but without softdevice

Now that our package is ready the only thing left to do is to finally program the board. Go ahead and insert it into a USB port on your computer. After you insert it two things can happen. You could see the LD2 slowly pulsing red, or you could see something else. If you see LD2 pulsing red that means that the board is in bootloader mode and is ready to accept our program. If LD2 is not pulsing red, then just reset it with a reset button that is located on the left side of the board.

After a reset, LD2 should start pulsing red, and you should have a new device connected on your computer. If on windows you can look it up on device manager:

You need to remember what COM port is assigned to the board because we will need it now. Go to the terminal and type in this command:

nrfutil dfu usb_serial -pkg zip.zip -p COM6 -b 115200

Replace the COM6 with your port number, or if on Linux or Mac with a corresponding file path. When you hit enter, you should see a progress bar, and a short message “Device programmed.” after the programming is complete. All leds on board should be turning on one after another, and then turn off at the same time, and repeat indefinitely. If you see that then congratulations! The board is programmed successfully!

To find out how to flash a softdevice along with the application .hex file click here.