STM32 FreeRTOS no sockets

[General-Dracula]

Hello,

I want to use libcoap with my STM32WB5 project. I am running FreeRTOS without any sockets and communicating via UART to a Telit without any network stack, just a straight UART buffer to the Telit running a UDP connection.

What do I have to do to port it for my use case?

[mrdeep1]

I have not used FreeRTOS before.

From libcoap's perspective, there is a netif layer that sits between the CoAP (or optional DTLS layer) and socket layers. There is a set of coap_netif_*() functions in this layer. These coap_netif_*() functions then call socket functions as is appropriate.

There is no reason as to why you cannot write your own coap_netif_*() functions that handles the UDP packets as they come in / go out of the UART. See Netif Support which outlines what the different functions have to do. Further detail can be found in src/coap_netif.c.

Alternatively, you can create your own coap_socket_*() functions that handle the UDP packets as they come in / go out of the UART. There currently is Posix (src/coap_io.c), LwIP (src/coap_io_lwip.c) and Contiki (src/coap_io_contiki.c) to support the different ways that sockets are done in those environments. See Datagram (UDP) Support for the function definitions.

There is also libcoap support in the Espressif ESP-IDF development environment which may have all the pieces that you need.