Thread: how to communicate and get back data from a specific devices using C language

Presumably the device comes with some physical means of communicating with the computer (say a port, a connector, an antenna) as well as a specification of the protocol it uses to communicate.

Generally speaking, however, the means of communicating with physical devices is not specified in the C standard. That is typically achieved via some logical interface (for example, an API - Application Programmer Interface - or a set of functions in a library that can be called from a C program). If you're lucky, the device uses a common port that most computers ship with and your host operating system will have some built-in means of communicating with that port (say a device driver and API). If not, the supplier of the device would normally provide such a library (which would be tailored for your host system and development environment if needed).