Nitrogen

Repository Overview

The stm32samples repository is a collection of low-level, bare-metal code examples and complete projects for various STM32 microcontroller series (F0, F1, F3, F4, G0). It uses CMSIS header files from modm-io/cmsis-header-stm32 for register definitions.

Project Structure by MCU Series

STM32F0 (F030, F042, F072)

• 3steppersLB – Controls 3 stepper motors with encoders via USB/CAN bus
• blink – Simple LED toggling
• CANbus4BTA – CAN replacement for PEP-CAN
• CANBUS_SSI – Works with BTA SSI azimuth encoder
• Chiller – Basic chiller temperature controller
• F0_testbrd – Tests STM32F0x2 on custom board
• htu21d_nucleo – Reads HTU-21D sensor on Nucleo-F042K
• morze – Echoes USART1 data as Morse code on TIM3CH1 (PA6)
• NUCLEO_SPI – SSI over SPI on Nucleo-F042K
• PL2303_ringbuffer – USB CDC ACM with ring buffers
• QuadEncoder – Quadrature encoder via timer
• Servo – Controls SG-90 style servos
• Socket_fans – Manages multiple fans
• TM1637 – Drives 7‑segment displays
• tsys01_nucleo – Reads two TSYS01 sensors
• uart_blink & uart_blink_dma – USART echo with DMA
• usbcan_relay – Relay board over CAN bus
• usbcan_ringbuffer – USB‑CAN adapter with ring buffers
• USBHID – USB HID keyboard + mouse

STM32F1 (F103)

• BMP180, BMP280 – I²C temperature/pressure sensors
• Canon_managing_device – Controls Canon lenses
• canUART – UART‑CAN bridge
• DHT22_DHT11 – Humidity sensors using timer+DMA
• DS18 – DS18x20 temperature sensors
• F1_testbrd – Test board for LQFP48 packages
• I2Cscan – I²C scanner with register R/W
• LED_Screen – Drives 32×16 LED matrices (P10)
• MAX7219_screen – Controls 8×8 LED matrices
• RGB_LED_Screen – HUB75E RGB panel with 8.8.4 color
• SevenCDCs – Seven USB‑CDC ACM instances on one MCU (joke project)
• shutter – Bistable shutter via USB/external signal
• Tetris – Tetris on HUB75E panel
• USB_HID – USB HID mouse+keyboard
• ws2815 – Rainbow effect on WS2815 strips

STM32F3 (F303)

• ADC – Works with ADC peripheral
• blink – Toggles LEDs on PB0/PB1
• CANusb – USB‑CAN adapter
• floatPrintf – Converts floats to strings
• Multistepper – Controls up to 64 multiplexed steppers
• NitrogenFlooding – Automatic nitrogen flooding
• PL2303 – PL2303 emulator (old)
• Seven_CDCs – Seven USB CDC ACM interfaces
• usart1fullDMA – USART1 Rx/Tx DMA with match detection
• USB_template_CDC – USB‑CDC template

STM32F4 (F401)

• blink – Simple LED toggling

STM32G0 (G070, G0B1)

• blink – Basic LED blink
• RTC – Real‑time clock
• flash – Flash memory operations
• g0b1 – USB‑CDC working on G0B1
• i2c – I²C operations
• usart – USART communication

Other Directories

• deprecated – Archive of older, no‑longer‑maintained code
• snippets – Small reusable code fragments
• testboard – KiCad 8 design files

Development Environment

• Toolchain: arm-none-eabi‑gcc with -flto optimisations
• Build: Structured Makefiles per series
• Debug: OpenOCD configuration files provided
• Libraries: No third‑party libraries; only CMSIS‑SVD headers

Project Maturity

• Alpha: USB template for F303, MLX90640 all‑sky camera
• Stable: LED blink, UART echo, sensor interfaces, USB‑CDC
• Draft: CANbus4BTA, MLX90640multi
• Deprecated: Older code in deprecated/

Summary

This repository is a valuable resource for learning low‑level STM32 programming without vendor libraries. It covers practical applications:

• Industrial control: Stepper motors, CAN bus, relay boards
• Sensor interfacing: Temperature, pressure, humidity, encoders
• Human‑machine interfaces: LED matrices, 7‑segment displays, USB HID
• Communication: UART, SPI, I²C, USB‑CDC, USB‑HID, CAN
• Prototyping: Test boards for F0, F1, F3, G0

For the latest updates, check the repository on GitHub.

License

This repository is provided under the GNU General Public License v3 or later. Full text of the GPLv3 is available at https://www.gnu.org/licenses/gpl-3.0.html.