DFU Application Size Change

[ishgum]

I have been doing some testing around DFU and I have noticed something strange.

My application size (according to nRF Connect memory read) is about 78 kB. (Left Image)

When I complete a DFU with the same program the application size becomes 155kB which is roughly double. (Right Image)

I know that the DFU has two banks, and that it copies the application from one to the other, I just would've expected it to clear the memory there after performing the DFU so that the application size would be identical between them.

Is this the expected behaviour or is there something going wrong?

DFU performed with an Android nRF Connect

SDK 14.1

nRF52832

SD5

[AndreasF]

Hi.

The bootloader does not delete the memory area after the DFU unless you tell it to do so, since it is a waist of time and energy. You should therefore be sure that the bootloader deletes the memory area before the DFU.

Best regards,

Andreas