C Programming for Embedded Work
C is the working language of embedded development. This module moves past syntax into the memory model, undefined behaviour and debugging discipline that firmware work actually depends on.
Prerequisites
- No prior programming experience required
- Comfort with basic high-school mathematics
Learning objectives
- Read and write C that manipulates memory deliberately rather than accidentally.
- Explain how a program is translated, linked and loaded.
- Diagnose common defects using a debugger instead of guessing.
- Implement and use basic data structures in C.
Detailed topics
Language core
- Fundamentals: control flow, scope, functions, recursion
- Data types, qualifiers, conversions and integer promotion
- Operators and operator precedence
- Arrays and strings (including NUL-termination discipline)
- Structures, unions, enums and bit-fields
Memory model
- Pointers and pointer arithmetic
- Function pointers and callbacks
- Arrays vs pointers, multi-dimensional arrays
- Memory layout: text, data, BSS, heap, stack
- Storage duration: automatic, static, thread, allocated
- Dynamic allocation and why embedded code often avoids it
Embedded-critical idioms
- Bit manipulation: masks, shifts, set/clear/test, bitwise tricks
- const, volatile and restriction — what the compiler may assume
- Register access patterns and read-modify-write hazards
- Preprocessor: macros, conditionals, include guards, token pasting
Toolchain and correctness
- Compilation stages: preprocess, compile, assemble, link
- Object files, symbols, sections and the linker map
- Debugging with GDB / an IDE debugger: breakpoints, watchpoints, stepping
- Common programming errors, undefined behaviour and edge cases
- Data structures in C: linked lists, stacks, queues, hash maps
Practical exercises
- Write a memory-layout explorer that prints addresses of globals, locals and heap allocations.
- Implement a ring buffer with fixed storage and prove overflow behaviour under stress.
- Build a bit-field register simulation for a fictional peripheral.
- Reproduce and fix five seeded bugs in a provided C codebase using only a debugger.
Assessment
Timed Embedded C worksheet (pointers, memory, volatile) plus a code review of a provided module against a published checklist.
Project milestone
A reviewed, documented utility library (ring buffer, dynamic string, CRC) with unit tests.
Required hardware
- Any computer capable of running a C toolchain
Required software
- GCC or clang
- GDB / IDE debugger
- Make or CMake
- Editor or IDE of choice
Expected learning outcomes
- Can read unfamiliar C and explain its memory behaviour.
- Can write defensive C with explicit bounds and lifetime rules.
- Can locate defects with a debugger rather than by print statements alone.