stm32f401-cpp-hal

C++ peripheral drivers for the STM32F401, built directly on CMSIS headers, no STM32Cube, no C HAL, no libopencm3. Targets C++20 with -fno-exceptions -fno-rtti.

Design

• Each peripheral is a class. Construction configures the hardware and enables the peripheral clock automatically.
• Copy is deleted; move is implemented, ownership of a peripheral can be transferred but not shared.
• Register fields are modeled as scoped enums, so every config value is type-checked at compile time.
• None / sentinel values on enums let you skip fields you don't care about without extra overloads.

Drivers

GPIO (gpio.hpp)

GPIO led(GPIOC, 10, GPIO::Mode::Output);
GPIO btn(GPIOC, 12, GPIO::Mode::Input,
         GPIO::OutputType::None, GPIO::Speed::None, GPIO::Pull::PullUp);

led.set();
led.toggle();
bool state = btn.get();

EXTI interrupt with edge-triggered callback:

btn.setInterruptCallback(GPIO::Edge::Fall, [](void* ctx) {
    static_cast<GPIO*>(ctx)->toggle();
}, &led);

Shared EXTI lines (EXTI9_5, EXTI15_10) are managed internally , enabling/disabling the NVIC line only when no other pin on that range is active.

UART (uart.hpp)

UART uart(USART2, {GPIOA, 2}, {GPIOA, 3}); // tx, rx , AF7 defaulted via PinConfig
uart.setStdout(); // routes printf → this UART via _write syscall

uart.send(buf, len, /*timeout_ms=*/100);

Baud rate is derived at runtime from SystemCoreClock and the APB prescaler , no magic constants.

Supports: word length, stop bits, parity, oversampling (×8/×16), hardware flow control (RTS/CTS).

Files

File	Purpose
common.hpp	Callback struct, freestanding move()
gpio.hpp/cpp	GPIO + EXTI driver
uart.hpp/cpp	UART driver
pinConfig.hpp	PinConfig , bundles port/pin/AF for passing to UART

Dependencies

• CMSIS core headers (core_cm4.h)
• STM32F4xx device headers (stm32f401xe.h via stm32f4xx.h)
• SystemCoreClock must be set before constructing a UART (done in startup)