Buttonless bootloader on custom board

RE: Buttonless bootloader on custom board

Hung Bui — Mon, 18 Jan 2021 14:19:27 GMT

Hi RMV,
Please create a new case when you have a question. Posting it on someone's case may end up no reply.

BUTTON_PULL is defined in the board. h file, for example if you are using pca10040 board, it's defined in pca10040.h

#define BUTTON_PULL NRF_GPIO_PIN_PULLUP

RE: Buttonless bootloader on custom board

RVM — Sun, 17 Jan 2021 22:40:53 GMT

I am trying to achieve something similar on my custom board. I have worked around many of the hiccups I am stuck due to a build error.

When compiling the file 'nrf_bootloader.c' the build fails with this error:
nRF5_SDK/16.0.0/components/libraries/bootloader/nrf_bootloader.c:231:30: error: 'BUTTON_PULL' undeclared (first use in this function)
231 | BUTTON_PULL,

I have a custom board and my plan is to do DFU over BLE.

My question is: Why do I have to worry about defining the BUTTON_PULL to begin with since I have no intention of using any GPIO to trigger entry into DFU. Do I even need to compile this specific file for my build?

RMV

RE: Buttonless bootloader on custom board

Hung Bui — Wed, 09 Dec 2020 13:59:22 GMT

Hi Rahul,

1. Please have a look inside ble_app_buttonless project. The service is declared in ble_dfu.c (ble_dfu_buttonless_init()) , depends on if you do DFU with or without bond you would need ble_dfu_bonded.c or ble_dfu_unbonded.c

2. It's inside ble_dfu_buttonless_bootloader_start_finalize() we don't reset immediately but gracefully disconnect before we reset.

3. Its the nRF Connect feature to support DFU buttonless. Are you planning to build your own app/DFU app? You can refer to the DFU profile inside nRF Toolbox. The nRF Connect is not really you should send to the end customer. It's a debug tool.

RE: Buttonless bootloader on custom board

Rahul Chowdary — Tue, 08 Dec 2020 12:41:13 GMT

Hi Mr. Bui,

Thanks for the information. Now, I got full clarity on how it is working and I could be able to successfully test the buttonless DFU example. I want to implement the same functionality into a template application. So here are my doubts.

When I connect to the Nordic_Buttonless in nRF connect for android, I could see the "Secure DFU service" as shown in image 1 with characteristic "Buttonless DFU".

When I click on the characteristic "Buttonless DFU" it is giving the option to launch the bootloader and just launching the bootloader when yes is given. On the other hand when I click the DFU symbol present on top right corner it is asking to select the firmware zip package and when selected the zip package, it is automatically launching the booltoader and connecting to the bootloader and updating the application. Now, I want to know below things.

1) Which file is responsible for adding the DFU service and Buttonless dfu characteristic to it (I believe it is nrf_dfu_ble.c) ?

2) When we send the characteristic to lanuch into bootloader mode, we will write the magic value to the retention register (GPREGRET) and do the soft reset. So, in which file we are doing this process ?

3) How can I just add the buttonless DFU characteristic without the DFU symbol on top right corner ?

Thanks in advance for your help.

Regards

Rahul Chowdary

RE: Buttonless bootloader on custom board

Hung Bui — Wed, 02 Dec 2020 14:21:56 GMT

Hi Rahul,

Please be aware that when you testing buttonless application, you still need to flash the normal bootloader. There is no such thing as " buttonless dfu bootloader". The buttonless example provided in the SDK is an example of how to implement buttonlessDFU service into your application.
So what you need to do is to implement the buttonless service into your blinky (i assume it's a BLE application) application. And you still need to flash the normal bootloader.
You can choose to make the bootloader setting or not (if you don't make the bootloader setting you will need to flash the application via DFU process instead of flashing it directly via the programmer).

I have a tutorial here that may have some extra information about that.