STM32 Toaster Oven Controller

This was my first embedded project. I built it on an STM32 Nucleo development board — USB-powered, ST-Link onboard — with a black expansion shield stacked on top for buttons, switches, a potentiometer, UART headers, and a small OLED (early bring-up showed Hello World!).

Appliance-style control is a classic embedded problem: debounce inputs, manage timed heating states, and respond to temperature feedback without blocking the MCU.

• Learn STM32 firmware on a Nucleo board from scratch
• Clear finite-state-machine architecture
• Button and ADC temperature / knob input handling
• Timed control states for heating cycles

STM32 Nucleo as the MCU platform, plus a shield with: - OLED (I²C — SDA/SCL) - Push buttons and slide switches - Potentiometer for analog input - Buffered headers (74HC244) and UART breakouts for peripherals

Inputs (buttons, ADC) → FSM (idle, preheat, bake/toast, fault/done) → outputs (heater drive indicators / control signals) with timing services on the Nucleo.

The controller is an explicit state machine in C. Each state defines entry actions, transitions, and timing. ADC readings inform temperature-related transitions.

• FSM over ad-hoc flags for predictable behavior and easier testing
• Nucleo so I could flash and debug over USB without a separate programmer

Exercised state transitions with button sequences and ADC / pot inputs on the Nucleo + shield stack, verifying timing and control-state behavior.

A working STM32 Nucleo FSM controller — my first end-to-end embedded stack from board bring-up through structured appliance-style control logic.

• First-time toolchains, flashing, and peripheral bring-up
• Debouncing and input edge cases
• Accurate timing without busy-waiting

Explicit states and transition tables make embedded control far easier to reason about than deeply nested conditionals — and a Nucleo is a forgiving place to learn that.

• PID temperature regulation overlay
• Soft-start heater drive
• Logging/telemetry for lab demos