RE: mesh dfu impressions

AndyM — Mon, 14 Oct 2024 13:29:17 GMT

Thank you very much for your feedback

RE: mesh dfu impressions

Elfving — Mon, 14 Oct 2024 11:47:27 GMT

Hello,

[quote user=""]

1. It's SLOW. The DFU image size is 330K and it took 30 minutes to download it. There were only 2 nodes on the mesh network, the target and the distributor, sitting next to each other. The network I'm evaluating this for has over hundred nodes spread over a very large territory and my DFU images are larger, about 415K.

[/quote]

First of all, no matter what you do a Mesh DFU will generally be slow, compared to eg. a normal BLE DFU. I acctually remember as an example that a DFU of 420kB could take two hours. This is due to Mesh not really being designed for high throughput applications. This will also be the case if you want to send any large file accross the Mesh network. Though in situations where you have a large network that is continously online then this is often not considered a problem.

Another thing to note is that it is hard to say anything about how much slower anything will be in a larger network. How long it takes for something to spread over this large network of yours won't be proportional to how long it took for it to spread to 2 nodes, since the first node will spread the DFU package to all nodes that are close to it, not just the second node. And this will then continue for the next node in line.

[quote user=""]Is mesh DFU even feasible in my situation?[/quote]

Sure it is. And if you are doing BLE Mesh, then I don't really see what other practical options you have. But if your network is indeed big, and span a wide area, then Mesh DFU sounds perfect to me, since you won't have to deal with any one individual node. One operation will handle the entire network, no matter how large of an area you have, or how many nodes there are.

[quote user=""]Any suggestions to speed up the process?[/quote]

There are some things that you can do to increase the performance, though it would either way take some time. The mesh node is limited to an average message rate of less than 10Hz. And there might be other things you want to keep in mind and optimize for when configuring the network, not just throughput.

[quote user=""]

2. The JSON messages returned from mesh models dfd receivers-get command on the distributor are too cryptic

[/quote]

Noted.

[quote user=""]3. Some documentation recommends using a VERSION file when building a DFU image with this format
[/quote]

My understanding is that both can be used, but using a version file is recommended and considered more flexible. CONFIG_MCUBOOT_IMGTOOL_SIGN_VERSION is however easier, for demonstration purposes.

Regards,

Elfving