A microcontroller is a complete small computer on a single chip, and knowing what is inside it explains most of what you will do later in firmware. The CPU runs your instructions, the memory holds your program and your data, and the peripherals (timers, converters, and communication blocks) connect the chip to the outside world.
You'll start with how an MCU is put together, then look at its memory: registers, RAM, Flash, and EEPROM, and what each one is for. From there you'll see how memory-mapped I/O lets plain reads and writes to an address control real pins and devices, which is the idea underneath every hardware library you will use.
The module ends with a comparison of the major chip families, including ESP32, STM32, nRF52, and RP2040, so you can choose hardware that fits a project. Once you've finished, move on to Embedded C & C++ to start writing the code that runs on it.
A first look inside the chip: the CPU, the memory, and the built-in peripherals such as timers, converters, and communication modules that make a microcontroller a small computer on a single chip.
The kinds of memory a microcontroller has, from CPU and peripheral registers to RAM, Flash, and EEPROM, what each one is used for, and how every word of memory has an address.
Memory-mapped I/O in practice: how writing a value to an address toggles a pin or drives a device, shown on Arduino, STM32, and Nordic boards.
A comparison of four popular microcontroller families on wireless support, power use, cost, and ecosystem, with a simple way to decide which one fits a project.