How add LwIP in a non-Ethernet device?

DCajigal · ‎2021-09-22

Hi,

This is my first project trying to use lwIp, so sorry for all the mistakes that i could be making...

The thing is that i would need to use lwIp over a STM32F479VI LQFP100. But this mcu does not have Ethernet, so the lwIp option does not appear in CubeMX. I have been reading and trying to understand how could i include this library in order to use it in a standalone environment, but i am not getting it to work.

I have tried to download the lwIp 1.4.1 version from:

http://savannah.nongnu.org/projects/LwIP

And include it under Middlewares -> Third_Party.

But it does not compile, saying that some files like "config.h" are missing.

Someone could help me with this? Thank you in advance!

Danish1 · ‎2021-09-23

Have you considered how you would actually use LWIP (a networking library) on a device that doesn't have a network interface?

It can be done (I use LWIP talking to a cellular modem over a serial port using PPPoS) but it's far from the "standard" configuration. The way I brought this up was to start with a processor that did have an Ethernet interface, got LWIP working there, and then copied the code over to my chosen processor. And then had the non-trivial task of getting PPPoS working.

I will add that I don't use stm32Cube (I prefer Rowley Crossworks, and can justify its cost for my projects). So I'm not steered towards the software ports that ST have done. This has advantages and disadvantages.

An obvious disadvantage is that I have to do the porting myself - although I do peek at how it was done for stm32Cube.

But an advantage is that I am not tied to the version of the library that ST ported. LWIP1.4.1 is seriously old. I don't believe that it has PPPoS, and no doubt many bugs have been discovered and fixed since then.

Hope this helps,

Danish

DCajigal · ‎2021-09-23

Hi!

My case here is the same, i have a GPRS modem and i was also thinking about using LWIP with PPPos. First i was trying to get LWIP to work and then i tought that i only had to add some functions to be able to use PPP, like it is said here:

https://lwip.fandom.com/wiki/PPP#PPP_over_serial

Regarding to the version i was trying to configure LWIP in an Ethernet device and i have seen that the actual version is the 2.1.12. However, in CubeMX appears a PPP option but cant be enabled (dont know why).

Could you help me with this a bit? Thank you a lot!