SwiftCoAP + LWM2M? about swiftcoap

[mlindstedt]

Hi Stuffrabbit,

you had very quick answers on my other 2 questions, do you have an answer on this question too?

[stuffrabbit]

Hey mlindstedt,
sorry for the late answer. To be short: No have not implemented any LWM2M integrations till now. Maybe you can start a fork? :)

[mlindstedt]

Hi stuffrabbit,

I actually started on a LWM2M integration, for REGISTER / DEREGISTER and they worked fine. However when I implemented READ, then I ran into severe problems in SwiftCoap-code and I was doing lot of debugging in your code to try to find problem, the bits and bytes on Coap-level doesn't seem to be sent correctly. After several days of debugging, and not being able to make it work, I unfortunately had to abandon, and instead decided to go with Wakamaa implementation:

https://github.com/eclipse/wakaama

Even though Wakamaa is written in C, I managed to integrate the library into my Swift app.

Afterwards it has come to my attention that Firefox web browser:
https://addons.mozilla.org/en-US/firefox/addon/oma-lwm2m-devkit/
used PUT and not POST for LWM2M READ and that might be the reason why it didn't work..

[stuffrabbit]

Hi mlindstedt,
good to hear that you were able to find a solution for your problem. So you mean that there is a bug inside the CoAP-message parsing of SwiftCoAP? Or what were these severe problems about?

[mlindstedt]

It seems to me that there is a bug, but I only put in 4 debug working days, before I gave up. Like I said, when I implemented LWM2M register and deregister on top of SwiftCoap in my iOS app, then SwiftCoap worked fine, but when I implemented LWM2M read or execute, then SwiftCoap didn't make other side trigger on what it sent, so either the problem was in SwiftCoap or in the other end (LWM2M client).

In my case I used Firefox web browser with a plugin, to use it as LWM2M client, whilst the iOS app with SwiftCoap was LWM2M server.

However, later on it turned out, that Firefox plugin was not correctly implemented, it followed old LWM2M standard which made it use PUT and not POST for LWM2M read, which might be reason why it didn't work.

But, I also tried Wakamaa as LWM2M client towards my iOS app and it had same problem, so my suggestion is that you try to implement some parts of the upper layer, i.e LWM2M on top of SwiftCoap, to see if you can make it work. REGISTER and READ should be enough for you to see if you can get same problem.