C: The Language of Embedded Systems

C has powered microcontrollers and embedded devices for over 40 years, and it still runs most of the electronics around you.

C sits close to the hardware while still reading like normal text, which is why it became the default language for embedded systems. It lets a programmer control individual bits in a register, manage memory directly, and produce code that runs predictably fast — all things that matter on a chip with a few kilobytes of RAM.

Most microcontroller manufacturers ship their chip libraries in C, and most real-time operating systems for small devices are written in C as well. Learning to read C is close to a requirement for understanding datasheets, example code, and open-source firmware projects.

The trade-off is that C gives very little protection against mistakes: it's easy to write past the end of an array or misuse a pointer. In exchange, you get a language with almost no hidden overhead — what you write is close to what the chip actually executes.