Secure DFU OTA for nRF52840 solution modules: Guide to create hex/zip file for implementation – #2(Application)

Following up-Part A: Bootloader (Click for article link)

We will be focusing on:

in this article.

IC: nRF52840
DK: PCA10056 (for nRF52840)
SDK: 17.1.0
Softdevice: s140_nrf52_7.2.0_softdevice.hex
IDE: Keil C
PC: Win 10


Path: nRF5_SDK_17.1.0_ddde560\examples\ble_peripheral\ble_app_uart\pca10056\s140\arm5_no_packs

Before building Application code , some amendments need to be made regarding DFU-related settings and code inside Application:

Step 1.


1A. Add code in definition in C/C++ :
BL_SETTINGS_ACCESS_ONLY NRF_DFU_SVCI_ENABLED NRF_DFU_TRANSPORT_BLE=1
(Total 3 steps definitions need to be set up)


1B. Add “include path” in C/C++


1C. Add the .c files inside red frame in (Screenshots 1 & 2)
and the 2 groups of (nRF_DFU & nRF_SVC)(Screenshot 3) under Project(Screenshot 4)



1D. Add code into main.c file in Application (..\examples\ble_peripheral\ble_app_uart\main.c)
(Please refer to: main.c file at: ..\examples\ble_peripheral\ ble_app_buttonless_dfu)


1E. The code of file: sdk_config.h (..\examples\ble_peripheral\ble_app_uart\pca10056\s140\config\
sdk_config.h) inside Application needs to be modified.


1F. Adjust the IRAM1 value in Target after implementing DFU service:
Check on the IRAM1 Value of *p_app_ram_start to be modified from default: 0x20002AE8 0x3D518 to 0x20002AF8 0x3D508, as shown in the red frame in the bottom right corner.
In this case, the program should run successfully.


1G: Create a file of: nrf52840_xxaa.hex after building application code files.


Step 2. Create a bootloader setting file of nrf52840_bootloader_secure_settings.hex : (via DOS)

nrfutil settings generate –family NRF52840 –application nrf52840_xxaa.hex –application-version 3 — bootloader-version 2 –bl-settings-version 1 nrf52840_bootloader_secure_settings.hex –no-backup


※Stay tuned for #3 – Part C: Combining and merging built files in the next article,

scheduled release in next week(05/06/2024).


Technical guidelines provided by R&D Manager: Mr. MW Lee
Edited by Sales Manager: Mr. Tony Yin

Raytac Corporation 勁達國際電子股份有限公司 
Bluetooth & WiFi module maker based on Nordic nRF54, nRF53, nRF52, nRF7002 solution
BT5.4 &BT5.3 & BT5.2 & BT5.1 Qualified, FCC/IC/CE/Telec/KC/RCM/SRRC/NCC Pre-Certified.
Bluetooth Solution: nRF54, nRF5340, nRF52840, nRF52833, nRF52832, nRF52820, nRF52811, nRF52810, nRF52805, nRF51822
WiFi Solution: nRF7002
http://www.raytac.com
email: service@raytac.com
Tel: +886-2-3234-0208

Secure DFU OTA for nRF52840 solution modules: Guide to create hex/zip file for implementation – #1(Bootloader)

Below are the following steps to implement Secure DFU OTA by using nRF52840 chip set, SDK17.1.0.
It consists of 3 parts:

Part A: Bootloader

Part B: Application (Click for article link)

Part C: Combining and merging built files (Click for article link)

In this article, we will be focusing on Part A: Bootloader.

Path: nRF5_SDK_17.1.0_ddde560\examples\dfu\secure_bootloader\pca10056_s140_ble\arm5_no_packs


Step 1. An error may occur while building bootloader without a public key:
(Shown in red frames in below screenshot)


Step 2. How to generate the public key file in Bootloader?
A. Visit DOS at path: ..\Python27\Scripts
B. Then execute:

nrfutil keys generate private.pem
nrfutil keys display --key pk --format code private.pem --out_file public_key.c


Step 3. Copy the pk[64] code from (public_key.c) into (dfu_public_key.c)
(Shown in red frames in below screenshot)

※Note: Make sure to save the 3 generated files:
private.pem
public_key.c
dfu_public_key.c


Step 4. Generate the bootloader file: nrf52840_xxaa_s140.hex after re-compiling the code files.


※Stay tuned for #2 – Part B: Application in the next article, scheduled release in next week(29/05/2024).



Technical guidelines provided by R&D Manager: Mr. MW Lee
Edited by Sales Manager: Mr. Tony Yin


Raytac Corporation 勁達國際電子股份有限公司  A company of Abietec
Bluetooth & WiFi module maker based on Nordic nRF54, nRF53, nRF52, nRF7002 solution
BT5.4 &BT5.3 & BT5.2 & BT5.1 Qualified, FCC/IC/CE/Telec/KC/RCM/SRRC/NCC Pre-Certified.
Bluetooth Solution: nRF54, nRF5340, nRF52840, nRF52833, nRF52832, nRF52820, nRF52811, nRF52810, nRF52805, nRF51822
WiFi Solution: nRF7002
http://www.raytac.com
email: service@raytac.com
Tel: +886-2-3234-0208