Question about Bluetooth OTA and UART DFU with nRF54L05

[Kenta]

Hello.

I am trying Bluetooth OTA and UART DFU using nRF Connect SDK v3.0.2 and nRF54L15-DK.
I am following the DevAcademy and using the peripheral_uart project as a base.
academy.nordicsemi.com/.../

With nrf54l15dk/nrf54l15/cpuapp, everything works fine.

However, with nrf54l15dk/nrf54l05/cpuapp, there is no response in the case of UART DFU, and it does not seem to work.

The build results for peripheral_uart + UART DFU are as follows:

[6/7] Building C object zephyr/CMakeFiles/zephyr_final.dir/isr_tables.c.obj
[7/7] Linking C executable zephyr/zephyr.elf
Memory region Used Size Region Size %age Used
FLASH: 195128 B 210 KB 90.74%
RAM: 40112 B 96 KB 40.80%
IDT_LIST: 0 GB 32 KB 0.00%

peripheral_uart + Bluetooth OTA compiles successfully and runs, but when I upload dfu_application.zip to the DK, the message “Response payload values do not exist” appears on the nRF Connect app on my smartphone.

I have read previous posts, and I suspect that the reason it is not working is because there is not enough ROM capacity, rather than RAM.
devzone.nordicsemi.com/.../mcuboot-image-in-the-primary-slot-is-not-valid-unable-to-find-bootable-image

Is there a way to enable OTA or UART DFU on the nRF54L05?(Add external Flash?)

Best regards.

[Einar Thorsrud]

Hi,

You are close to using the available RRAM (at 90.74%), so it may be that wil need external flash. But it is not strictly needed if you have a small application, and here it does fit. Unless you need to fit a larger application I would start by debugging on the nRF side to see what is going wrong, as this shold work.

That said, if you need a larger application slot you need external flash. You can refer to the smp_svr sample with the nrf54l15dk_nrf54l15_cpuapp_ext_flash.overlay for how to do that. This is for nRF54L15 so sizes need adjusting, but appart from that the device and how it is used is identical.

[Kenta]

Hello Einar.
I'm sorry for the delayed response as it was summer vacation.

I understand from this thread that Bluetooth OTA for nRF54L05 seems to be challenging in terms of capacity.
devzone.nordicsemi.com/.../nrf54l05-cannot-ota

I tried the UART Serial DFU method referenced in this thread, and it worked successfully.
devzone.nordicsemi.com/.../mcuboot-won-t-boot-into-serial-recovery-mode-by-using-retained-memory

For now, I have confirmed that UART DFU (Single slot) is possible for the nRF54L05, so I will share this information with the my team.

This issue has been resolved for now, so this ticket can be closed.
Best regards.