Lots and lots of C. (I'm mostly an embedded C programmer these days). Some C++ for a bit of higher-level "business logic" that benefits from a class-based approach, but a fairly limited subset of "modern" C++.
Serious question: How does one get into this C embedded stuff? I'm addicted to low-level "embedded" type work. But all I hear back from are Django, RoR, $HOT_JS_FRAMEWORK, DevOps teams/recruiters. Is there some buzzword or special topic to know and do a project in? Any suggestions for projects to display on GitHub, topics to know through and through (domain specific knowledge)? I sit at work thinking all day about Ra…
For a reference of stuff to learn about, go grab the manuals (usually massive) for a recent embedded CPU and see what common topics are foreign to you. Just reading the TOC should prompt some ideas. You may not be applying for one of the lower level "board bring-up" type jobs, but that team will be delivering you libraries that assumes familiarity with IRQs, timers, memory paging, processor modes, DMA, lots of I/O types, etc.