Trying to downgrade DFU with NRF52 and SDK 17.0.2

[Cintia]

Hello,

I'm developing an application and I've implemented DFU. It is working properly, but I made three versions for tests, 1.0, 2.0 and 3.0.

I never tried to downgrade the versions before, and I noticed that when I try to go from 3.0 to 1.0, it just disconnects. Reading some other tickets I noticed there's a define on sdk_config.h to prevent downgrades, but I coulnd't find anything about it on SDK 17.0.2.

How can I downgrade through versions? I'm using s332 7.0.1 and SDK 17.0.2

Thanks in advance.

[Amanda Hsieh]

Hi, 

This post might help. Please let me know if anything is not clear. 

Regards,
Amanda H.

[Cintia]

Hi Amanda,

I saw this post before opening a new ticket. First I searched for that define in my sdk_config.h and it wasn't there, so I added and set it to 0. Then again I tried to downgrade my FW but it didn't work, still disconnecting.

Do you know anything else I could try?

Best regards.

[Amanda Hsieh]

Hi,

Cintia said:

I added and set it to 0.

Please set the config NRF_DFU_APP_DOWNGRADE_PREVENTION to 0 to disable it in sdk_config.h. 

-Amanda H

[Cintia]

Hi,

I tried performing the downgrade with the config NRF_DFU_APP_DOWNGRADE_PREVENTION set to 1 and later with 0, both failed. It tries to connect and start the DFU but it just disconnects.

[Amanda Hsieh]

Hi, 

Cintia said:

First I searched for that define in my sdk_config.h and it wasn't there, so I added and set it to 0.

Do you modify the sdk_config.h in the bootloader?

Cintia said:

I tried performing the downgrade with the config NRF_DFU_APP_DOWNGRADE_PREVENTION set to 1 and later with 0, both failed. It tries to connect and start the DFU but it just disconnects.

Could you test the bootloader example with debug version and provide the log?

-Amanda H.

[Cintia]

Hi Amanda,

Thanks for your help, I figured out what I was doing wrong: I was changing the application sdk_config, when I should be changing the bootloader sdk_config. Now I can downgrade through versions!

[Amanda Hsieh]

Happy to know it works. Thanks. 

-Amanda H.