MESH DFU

[Pham Nam]

Hi team.

we are developing project using nrf52 mesh sdk including 1 port nRF52840 and other nrf52 devices. we are finishing dfu mesh for devices.

The nRF52840 gateway can download manifest.json, fw.bin, fw.dat and update the port itself through mesh dfu, of course it can also update other devices like switches..,

with fw is as small as blink_led that they can run. however with fw we grow to about 100kb,

when updating always get error NRF_MESH_DFU_END_ERROR_PACKET_LOSS from switches device side after receiving 64 packets.
Is there a way for our nRF52840 gateway device to know which data packet is missing from the switch for retransmission?

[Amanda Hsieh]

Hi Pham, 

What version of SDK are you using?

The nRF52840 gateway can download manifest.json, fw.bin, fw.dat and update the port itself through mesh dfu

I don't really understand what you meant here. Do you receive those files via the internet then update them to the mesh network? 

Please elaborate in more detail about how you update it to the mesh network. Thanks. 

-Amanda H.

[Pham Nam]

Hi Amanda.

We are developing equipment including gateway using nRF52840 + W5500 to be able to have internet (A), switches using nRF52840 (B) and sensor using nRF52832 (C).
zip file obtained after using nrfutil for mesh network, we unzip and upload the .json .bin .dat files to the server.
Now A can download the above files and simulate the dfu process for devices B, C. devices B, C have been able to update through A, but this process often encounters the "Abort" error. event. Reason: 0x03" NRF_MESH_DFU_END_ERROR_PACKET_LOSS on the B, C side when the image file is 100kb large. That's because B, C received missing packets from A transmitted. At device A I want to receive a notification from B, C is missing a packet so that A can retransmit.
Do you have any events so that A can know which packets B and C need to add?
i am using nrf5_SDK_for_Mesh_v4.2.0_src for above devices.

[Amanda Hsieh]

Hi Pham, 

It is worth for you to read DFU documentation regarding data formats. It will clarify a bit better protocol understanding.

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.meshsdk.v5.0.0/md_doc_user_guide_modules_dfu_packet_format.html#dfu-packet-data-request

The DFU functionality already has the mechanism for restoring lost data. If the device understands that it lost any data it accumulates information about which data has been lost. In parallel to the main data stream, it will send Data Requests and receives Data Responses with lost pieces (from image sender or relay devices).

However, the device has limited source capacity and can accumulate a limited amount of information about lost data. If the device lost so much data it cannot recover it will generate the event that you see.  

Since DFU+bootloader quite autonomic functionality it does not send any events about lost data and tries to solve such communication issues by itself. 

 

I would recommend to you to play with a transfer rate to improve stability. Probably this is too fast to transfer within a noisy environment.

-Amanda H.

[Wanderzhd]

Hi Pham,

Any progress on the issue?

-Dong

[Pham Nam]

Hi Dong,

I am increasing the interval between packets to reduce errors.