nRF9160 SLM add PPP

[Zoptune]

HI,

I am currently working on a project where, for now, I only use the nRF9160 as an LTE-M modem connected to the main MCU which is an ESP32.

I am using the SLM application and everything works as expected when I use AT commands.

Now I want to use the nRF9160 in PPP mode because this is the most straightforward way to integrate it in the ESP SDK as all its components (http, qttt, ...) are base on lwIP.

I originally thought that the AT#XSEND command was what I needed to enter PPP mode but then I realized it is only intended to send raw data to an already opened socket.

Then I found that PPP is already implemented in the MoSH sample.

So before I dive into the code, my questions are:

- do I have to "only" integrate the PPP code in the SLM app and create custom AT commands that enters/exit PPP mode ?

- is there any red flag that will prevent it from working ?

- do you have any advise regarding this work ?

Thanks.

Regards

PS: I know that this sounds stupid to not take advantage of the nRF9160 TCP/IP stack but this will requires lot of work to integrate it to the ESP SDK and I want a working example asap.

[Didrik Rokhaug]

Hi,

I am not very familiar with PPP, but yes, I believe it will work. You might have to use a second UART for PPP, similar to what the MoSH does.

You might also be able to simply use the MoSH sample directly, though I haven't looked at the current consumption of the MoSH sample. It might end up being higher than the SLM where you have the #XSLEEP command.

Best regards,

Didrik

P.S. Due to holiday vacations, responses might be slower than normal. We apologize for the inconvenience.

[Zoptune]

Hi and thanks for your response.

Ok I will give it a try.

I will only use one UART as I only have one available and I will add a new mode in addition to SLM_AT_COMMAND_MODE, SLM_DATA_MODE and SLM_DFU_MODE.

If I end up with something satisfying enough I will push a PR

Regards and happy end of the year.