DFU SDK 15.0 - process resume after interruption

[drk_tg]

Hi,

I'm using nRF52840-DK , SDK 15.0, buttonless DFU sample + secure bootloader

I see that resuming DFU works only after disconnect, but no longer on sw reset or power down.
In previous SDKs resuming works in all cases. Now DFU starts from beginning. It this something that was planned or it's regression in sdk?

Best,
Chris.

[Edvin]

Hello,

This is a new feature in the SDK15 bootloader. Shortly explained, you have the choice to either store the bootloader packets in flash or in RAM.

When the DFU is stored in RAM, it will be lost if the connection is lost. The positive side by using RAM instead of Flash is that it is faster.

This means, if you have an implementation where power failures are frequent, you would want to use flash. In other cases, where power cycles are not a problem, it is often enough to reconnect (if the connection is lost).

 

If you want to use Flash instead of RAM, you must change a define in the bootloader projects sdk_config.h:

#define NRF_DFU_SAVE_PROGRESS_IN_FLASH 0

to

#define NRF_DFU_SAVE_PROGRESS_IN_FLASH 1

 

Right above this define, there is also a brief explanation of the options.

 

Best regards,

Edvin

[drk_tg]

Thank you for clarification.