RE: Mesh DFU bootloader replied error 84 78 85

Hung Bui — Thu, 01 Jul 2021 08:57:13 GMT

Hi Frank,

The Mesh DFU is not designed to have multiple DFU source at the same time. They will both relay the packets over air and will cause conflict.

Could you let me know why you want to do DFU update for both of them ? Why don't you just update one of them and let the other node just passively receive the new firmware ? (that's what the mesh DFU designed for, all nodes will receive the new firmware)

If you do need to update them at the same time and via serial, you may want to think of having a new DFU mode that it will not relay the message. It's not something designed with the mesh bootloader. Usually there is only 2 modes: only relay (when the DFU image is not for the node, it will only relay) and store and relay (when the image is for the node and it will also relay).
You can find this in the dfu example, inside mesh_evt_handler() there are 2 options, one is to call nrf_mesh_dfu_request() for store and relay, and the other is nrf_mesh_dfu_relay()

You would need to create a 3rd option that it only does store. You then need to modify the bootloader to allow this 3rd option. I don't have the exact instruction on how you would do this, but you may want to have a look into handle_data_packet() inside dfu_mesh.c file and look at how the do_relay variable is controlled. Your third option should be that you turn off the do_relay.