$ show eddyem/stm32samples
This repository is a large collection of bare-metal firmware projects for STM32 microcontrollers (F0, F1, F3, G0, G4 families), authored by Edward V. Emelianov. It contains dozens of independent example and application projects covering USB CDC virtual serial ports, CAN bus gateways, sensor drivers (BMP280, MLX90640, DHT22, DS18B20, etc.), stepper motor control, servo control, LED displays, and more. The code is written in C with direct register access (no HAL) and uses a custom USB stack with ring-buffer-based I/O. Each project is self-contained with its own main.c, hardware initialization, and command parser, typically communicating over USB or UART with a simple text-based protocol. The architecture is monolithic per project: a main loop processes periodic tasks (ADC sampling, sensor reads, CAN message handling) and responds to commands received via USB or UART. Key entry points are the main.c files in each project directory. Data flows involve sensor acquisition (ADC, I2C, SPI), optional processing (median filtering, dew point calculation), and output via USB CDC, CAN, or UART. External dependencies are minimal: only an ARM GCC toolchain and the STM32 CMSIS-like headers provided in the inc/ folder. The repository also includes KiCad PCB designs and gerber files for many projects, indicating a full hardware+software development cycle. While the code is functional and covers a wide range of embedded use cases, it suffers from significant code duplication (ringbuffer.c, usb.c, strfunc.c are copy-pasted across many projects) and lacks a centralized library or build system. Deprecated folders and multiple versions of similar projects (e.g., chronometer_v2, chronometer_v3) add clutter. The repository is best viewed as a personal collection of working examples and prototypes rather than a polished framework. However, several components (ring buffer, string utilities, USB stack) are well-implemented and could be extracted for reuse in other STM32 projects.
The LLM identified 3 files worth highlighting for reuse:
A generic, thread-safe circular byte buffer implementation used across many projects for USB and UART data buffering. Provides RB_write, RB_read, RB_readto, RB_hasbyte, RB_datalen, and RB_clearbuf functions with a busy flag for atomicity. The implementation is self-contained (no internal dependencies) and could be extracted into a standalone library for any embedded project needing a simple FIFO.
A set of preprocessor macros for GPIO pin manipulation (pin_set, pin_clear, pin_toggle, pin_read) that work across STM32 families by using generic register names. Also includes macros for LED control, USB pull-up, and watchdog setup. This file is included in many projects and provides a consistent, low-overhead hardware abstraction layer. It is reusable in any STM32 bare-metal project with minimal adaptation.
A collection of string conversion and formatting functions for embedded systems: u2str (unsigned int to string), i2str (signed int), uhex2str (hex), float2str (float with precision), hexdump, and getnum (parse decimal/hex from string). These are used across many projects for command parsing and debug output. The implementation is self-contained and avoids printf, making it suitable for resource-constrained MCUs.