RE: Flash/RAM overflow on example project for NRF52DK_NRF52805 / NCS

AHaug — Wed, 20 Dec 2023 15:23:28 GMT

Happy to help! :)

Kind regards,
Andreas

RE: Flash/RAM overflow on example project for NRF52DK_NRF52805 / NCS

underpickled — Tue, 19 Dec 2023 18:25:00 GMT

Thanks for the sanity check! Saved me a lot of time 🙂

RE: Flash/RAM overflow on example project for NRF52DK_NRF52805 / NCS

AHaug — Tue, 19 Dec 2023 13:08:37 GMT

Hi,

The short answer is yes, you're asking for too many features for the nRF5205.

The longer answer is that all of these features will, as you know, increase the ROM/RAM usage of your application image. In addition, if you intend to do dual bank DFU, which is normal for OTA DFU through BLE, you will effectively need to be able to fit 2x your application within your devices flash range since you need an application slot (mcuboot_primary application slot / slot0) to run your application from, and a secondary slot (mcuboot_secondary application slot / slot 1) to hold the update image.

This unofficial repository created by a colleague of mine explains this and refers to our official documentation while doing so https://github.com/hellesvik-nordic/samples_for_nrf_connect_sdk/tree/main/bootloader_samples

As I see it you have the following options

Upgrade to a device with more flash
Add an external flash device to store the secondary mcuboot slot
Remove features. A general rule of thumb is that the application image needs to be within the total available flash on the DK - MCUboot size - 2x application size - headers, trailers and swap slot
Use single bank serial recovery instead (do note that this will remove any fallback features as it will overwrite your application directly to the primary application slot).

There are some optimization to be done for your application w.r.t RAM and ROM, but I unfortunately don't think it will get you near what you need if you want dual bank BLE DFU

Kind regards,
Andreas