Phase 2 · Core

Goal: understand what a microcontroller is doing under the hood, and drive every common peripheral and bus from the datasheet alone.

Four modules, roughly 6 to 8 weeks. Still on the Pico 2.

Module	You will be able to	Time
4. How a microcontroller works	Explain fetch-decode-execute, the memory map, buses, clocks, and why "32-bit" and "Cortex-M" matter.	1 to 2 weeks
5. Peripherals	Configure GPIO, timers, PWM, ADC, interrupts, DMA, and a watchdog from the reference manual.	2 to 3 weeks
6. Communication	Drive UART, SPI, and I2C devices from their datasheets and read the traffic on a logic analyzer. Know what RS-485, CAN, and USB are for.	2 weeks
7. Toolchain and build	Explain what happens between main.c and a blinking LED: compiler, linker script, startup code, vector table, flashing.	1 week

Can I skip anything? Module 4 can be skimmed if you have taken a computer architecture course. Do not skip Module 7 even if it looks dry. It is the module most self-taught engineers are missing, and it shows in interviews.