DFU nRF52832 from a nRF52840 via UART

[Wes]

What are best practices for updating an nRF52832 via UART from an nRF52840?  There seem to be at least two problems to solve:

1. Transmitting the 832 image via BLE to the 840 where it would be stored in flash.
2. Transmitting the 832 image from the 840 over UART to the 832.

SDK16

[Hung Bui]

Hi Wes, 
For step 2, we have an example here that you can have a look. 

For step 1, we don't have an example for that, but what you need to do is either to modify the bootloader so that it can provide extra functionality to only store the 832 image without replacing the 840 image. Or you can implement the feature in your 840 application to receive the image when the application is running and store that in flash.