build openthread disabling uart

[Tiago Santos]

Hello everyone!

I'm working in a new project where i should use a nrf52840 with openthread.

the thing is: in this project we won't be using uart with CLI interface, but will be using it to communicate with other sensors (both uarts).

it took me a while to find out that my problem was with the openthread's build and that i should create a new one.

So, i saw here there is a FLAG to disable SPI, then I thought I could use something like that to disable uart as well. but still got nothing 

I tried to use the flag USB=1 as said here, to change between uart and usb, but when i do this, i'd need to change all other files in my project. thats why i'm searching for just a disable flags.

i'm using:

- ubuntu 18.04.2

- GNU make 4.1

- Nordic thread and zigbee sdk 2.0.0 (openthread branch: 704511c96e0d093139e4b80ef0739ed2d701afb1)

- Started my code from mqttsn_client_publisher example

Thanks in advance,

Tiago

[Lukasz Duda]

Hello Tiago,

Happy to hear that you are using OpenThread and nRF52840!

nRF52840 platform can be built without any platform's transport (UART, USB or SPI). We have added a new Makefile option called DISABLE_TRANSPORTS, that should solve the presented problem. 

https://github.com/openthread/openthread/blob/master/examples/Makefile-nrf52840#L102

https://github.com/openthread/openthread/pull/3561

You need just to set this flag to 1, e.g. call

make -f examples/Makefile-nrf52840 DISABLE_TRANSPORTS=1 ...OTHER_FLAGS...

Also, this change was incorporated in the newest SDK in version 3.1.0 (the SDK 2.0.0 does not have this feature), so I encourage you to switch to this version and generate OpenThread libraries that satisfy your application.

Note, that with this flag set to 1, you can't use CLI or NCP application, the build system will generate only the needed OpenThread libraries.

Let me know if that helps.

Regards,

Łukasz Duda

[Tiago Santos]

Hello Łukasz!

Thank you very much for your answer!

since I won't be working with NCP nor CLI that's the perfect solution for my project!

I was thinking in using CLI with USB including mqtt-sn libs (because there wasn't a mqtt-sn example for nrf52840 dongle) and maybe that would free the uart to be used as I'd like

Thanks again!

Best Regards

Tiago