STM32 Exploration

A set of code examples and comments to teach myself a bit more about microcontrollers.

Info

I've adapted most of the code by following along Vivonomicon's STM32 examples.

The additions to the code presented in the examples are:

• Porting the examples to other boards (specifically, Nucleo STM32F446RET6)
• Adding comments for parts that were new to me or to explain certain aspects in more detail
• Modifications and additions to make the Makefile support multiple targets (F031K6 and F446RE)

Contents

This repository contains code samples and examples to understand aspects of embedded programming from first principles.

• 01-basic contains linker scripts and ARM Thumb assembly.
• 02-main contains vector tables and C. It also explores the ELF binary format.
• 03-gpio takes input via a button and toggles an LED with memory-mapped IO.
• 04-interrupt does the same thing as 03-gpio but uses interrupts using the NVIC and EXTI peripherals.
• 05-timer explores the clock peripherals, specifically using the 16MHz HSI oscillator to drive a PLL and core clock (HCLK).
• 06-freertos explores configuration of and using FreeRTOS to blink LEDs at intervals.
• 07-rust generates a peripheral access crate using svd2rust, and then blinks LEDs with Rust.

Build and run

Development was done on macOS, so all the makefiles work on macOS. I have not verified that they work on Linux.

To build, make <target-name> should work, where target-name is either f031k6 or f446re.

To run,

• Run st-util.
• Type arm-none-eabi-gdb <output-name.elf>.
• In GDB, target extended-remote :4242.
• load, and then continue.

For the Rust mini-project, build with cargo build in the appropriate rust-blink directory, and run with openocd and cargo run.

Future

• I intend to continue learning more about embedded programming with this series! A few fundamentals that I haven't had the time to include the basic communication peripherals (UART, SPI, I2C).