nRF51422- Udate from SDKv 9.0.0 & S310 to SDKv 10.0.0 and including secure DFU and SES

[gbrown1966]

Hi,

We have a product in manufacture based on nRF4122, SDKv9.0.0 and using S310.

We are aware that this is nearly 5 years stable but are considering the options to upgrade to latest apps/tools/SDK.

The motivation being

1) MCP no longer supported

2) LnRFconnect no longer supports legacy DFU

3) concern that IoS/ Android apps will no longer support legacy DFU

4) dependence on IAR toolchain and a desire to start using Segger Embedded Studio.

5) Bug fixes available in later SDKs

From what we can understand we have only the option to move to SDK 10.0.0 since we are using nRF51 and using S310. Other SoftDevice/SDK options do not support this configuration.

Can you confirm this and also, what are the implications if we wish to implement secure DFU with SES development tools into SDK v 10.0.0? Are there any recommendations/guidance for doing so.

many thanks in advance

Geoff

[bjorn-spockeli]

Hi Geoff, 

 Allthough we do not support the S310 in the SDK releases after v10.0.0 it should still be possible to use the S310 API in later releases by replacing the header files in one of the examples and removing incompatible API calls. 

Hence, I would recommend migrating all the way to SDK v12.3.0, which is the last version of the nRF5 SDK that supports the nRF51 Series. You will then get all available bugfixes and improvements done in the nRF5 SDK for the nRF51 Series. 

However, from a DFU perspective it is not possible to perform a over-the-air DFU from legacy DFU to Secure DFU. This is because the Secure Bootloader has a larger flash footprint than the legacy bootloader. The bootloader start address is stored in the UICR registers on the nRF51 and these cannot be changed by on-chip code, see this answer. The only way to erase the UICR registers is to perform a full chip erase. So you will have to re-flash the nRF51 devices with a programmer to update from Legacy to Secure DFU. 

As for Segger Embedded Studio support, there is no "out-of-the-box" support for SES in SDK versions, but there are guides on how to convert Keil projects to SES projects on DevZone, see https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/segger-embedded-studio-a-cross-platform-ide

As for your concern about iOS/Android apps deprecating Legacy DFU support. The Nordic DFU libraries, links below, for iOS/Android will maintain Legacy DFU support as long as the nRF51 Series is in production, so no need to worry about that. 

https://github.com/NordicSemiconductor/IOS-Pods-DFU-Library

https://github.com/NordicSemiconductor/Android-DFU-Library

Best regards

Bjørn