mbr vs. blank?

[dvescovi]

In the 15.3 SDK I see different IDE projects setting under peripheral "mbr" directory and the "blank" directory.

What is the difference?

[Jørgen Holmefjord]

Hi,

The MBR - Master Boot Record is used to allow safe update of bootloader on the chip. The MBR is included on the nRF52840 Dongle, as this device contains a bootloader to allow programming applications through the USB port. Please see this tutorial for more details. Blank directory is used for devices that does not require a MBR/bootloader, for instance the nRF52 DK and nRF52840 DK. BLE examples require a softdevice, and the directories will be named s1xx/s2xx/s3xx, depending on which chip is used and which protocols are supported in the example.

Best regards,
Jørgen

[Jørgen Holmefjord]

It is just an example showing how to have the MBR present without using the Softdevice. Examples of this use-case is for instance DFU/bootloader over other wireless protocols, like Thread or Zigbee.