From v4.0 to v4.1


With Sming version 4.1 there are some backwards incompatible changes. This page is provided to help with migrating your applications.


In version 4.1 one can choose between different SSL implementations. At the moment Sming supports axTLS and BearSSL for creating SSL enabled clients and servers.

In order to allow multiple SSL adapters and seamless integration the library code had to be refactored and that introduced some breaking changes.

Detailed documentation can be found in SSL: Secure Sockets Layer.

See SSL: Upgrading for a migration guide.


The MultipartParser component has been decoupled from the framework and converted into a Library. In the process, the former config option ENABLE_HTTP_SERVER_MULTIPART has been removed. Therefore, in your, replace:



ARDUINO_LIBRARIES += MultipartParser

Also, the body parser for handling HTTP requests of content-type multipart/form-data must now be registered explicitly by the application code:

#include <MultipartParser.h>

HttpServer server;

server.setBodyParser(MIME_FORM_MULTIPART, formMultipartParser);