Hi and welcome to the community!
Let’s clear up some terminology,
GET/PUT/POST refer to different things.
TCP are transport layer protocols used on an IP network.
HTTP methods as defined in the Hyper Text Transfer Protocol which is an application layer protocol that runs on top of the
TCP transport layer protocol.
To communicate between an
OpenRemote you will either need to use a USB cable and make sure of serial communication utilising the
Serial Client Protocol (this means your
OpenRemote instance is running on hardware within USB cable reach of your
Arduino. Alternatively you need an
Arduino with IP interface (either a shield or an
Arduino model that has this already onboard), there is a great, vibrant community around
Arduino so that is the best place to get help and guidance on how to implement
TCP communication on your board; I’m not sure there are any
Arduino boards and libraries that support a full
HTTP stack so low level communication is the better option which will involve sending packets of data (could be
UTF-8 strings for example), the basics are the same independent of whether
TCP is used.
OpenRemote side then either is supported and information can be found in the wiki.
NOTE: There is a pending documentation update to provide more information about generic protocol (Serial, TCP, UDP, etc.) configuration so please keep an eye on the wiki and if necessary ask follow up questions here on the forum.