Embedded Rust on STM32

What you end up with: firmware running on real hardware. You will blink an LED, read a button, talk to an I2C sensor, run concurrent async tasks with Embassy, and put the chip to sleep between events.

Embedded is where Rust’s safety story is most convincing — no null pointers, no data races, no undefined behaviour in an interrupt handler — and where the tooling has quietly become better than C’s. It is a small audience, but a loyal one.

What you’ll build

• A flashing LED, then a button that changes the flash pattern
• defmt logging, viewed through probe-rs over the debug probe
• A temperature and humidity reading from an I2C sensor
• Two concurrent async tasks sharing state safely
• A low-power build that wakes on an interrupt

What you need

• An STM32 board — the STM32F4 “Black Pill” or NUCLEO-F401RE is the cheapest sane choice
• An ST-Link debug probe (built into NUCLEO boards), on-board or external
• probe-rs and the thumbv7em-none-eabihf target installed

Before you start

• Structs, enums, and pattern matching — register access is all enums and match
• Traits and generics — HALs are built from traits
• Concurrency and async — the last third of the track is async

Articles

• What you need to start embedded Rustthe board, the probe, and the cables
• Setting up the embedded toolchainthe target triple, probe-rs, and cargo flash
• Blinking an LEDembedded-hal, cortex-m, and a first flash
• Understanding no_stdno allocator, no panic message, no libc
• Reading a button with GPIO inputpull-ups, debounce, and polling versus interrupts
• PWM and controlling brightnesstimers and duty cycle
• Talking to an I2C sensorreading temperature from a BMP280
• Serial output and logging on a microcontrollerdefmt, RTT, and why not println!
• Async tasks on a microcontrollerembassy, and several things at once
• Sleep, wake, and battery lifelow-power modes and the current you actually measure

Where the code lives

embedded-stm32/ in the examples repository — one cargo project, one tag per article.