BADHAL – Bare-Metal Drivers for STM32

What is this?

BADHAL is basically just my personal HAL for the STM32F411CEU6. Nothing fancy or production-ready, just code I wrote to make my life easier when working with the MCU.

Includes:

• GPIO - easy pin setup, set/reset pins, configure alternate functions.
• NVIC - enable/disable interrupts, simple as that.
• SPI - SPI setup, DMA support.
• EXTI - external interrupts with configurable trigger.
• Assert (assert.h) - prints messages over UART if things go wrong.
• ILI9341 (ili9341.h) - basic LCD driver with DMA framebuffer support.
• DMA - DMA control and interrupts
• UART - Basic uart stuff
• SYSCFG - Syscfg, for now only for exti
• Flash - setup latency, caches, and prefetch.
• RCC - clock configuration
• Timers - basic timer setup
• Startup (startup_stm32f411ceu6.c) - startup file, plain and simple
• Simple linker script (stm32f411ceu6.ld)

Most of the drivers don’t cover every feature yet—just what I needed for my projects.

How to use it

1. Include the header in your project.
2. If a driver has a _IMPLEMENTATION define, enable it in one C file, or use it statically:

#define BAD_GPIO_IMPLEMENTATION
#include "badhal.h"

3. Use the function

// Configure PA5 as push-pull output
io_setup_pin(GPIOA, 5,
             MODER_output,
             0, // AF not used
             OSPEEDR_medium_speed,
             PUPDR_no_pull,
             OTYPR_push_pull);

// Toggle pin
io_pin_set(GPIOA, 5);
io_pin_reset(GPIOA, 5);

Do note that some of the functions can only be included once and used only in the file its included (io_setup_pin and all the rcc and flash stuff). Why is it this way? I just find it nicer when all the setup is in one place.

Notes

If you need multiple settings for your project just do this

#define ILI9341_SPI_FEATURES_CMD                \
                    (SPI_FEATURE_MASTER|        \
                    SPI_FEATURE_PRECALER_div_2| \
                    SPI_FEATURE_SOFTWARE_CS|    \
                    SPI_FEATURE_BIDIOE_TX_ONLY| \
                    SPI_FEATURE_BIDIRECTIONAL|  \
                    SPI_FEATURE_FRAME_FORMAT_8bit)

#define ILI9341_SPI_FEATURES_DMA                \
                (SPI_FEATURE_MASTER|            \
                SPI_FEATURE_PRECALER_div_2|     \
                SPI_FEATURE_SOFTWARE_CS|        \
                SPI_FEATURE_BIDIOE_TX_ONLY|     \
                SPI_FEATURE_BIDIRECTIONAL|      \
                SPI_FEATURE_FRAME_FORMAT_16bit| \
                SPI_FEATURE_FORMAT_MSB )

And then just make some helpers to apply them

static inline void ili9341_spi_fb_transmition_mode(){
    spi_disable(ILI9341_SPI);
    spi_setup(ILI9341_SPI,ILI9341_SPI_FEATURES_DMA,0,0);
    spi_enable(ILI9341_SPI);
}

static inline void ili9341_spi_control_transmition_mode(){
    spi_disable(ILI9341_SPI);;
    spi_setup(ILI9341_SPI,ILI9341_SPI_FEATURES_CMD,0,0);
    spi_enable(ILI9341_SPI);
}

The main(main.c) file implements an example that

• Setups main clock at 100mhz
• Setups apropriate latency / caching
• Setups peripheral clocks
• Setups pins for SPI
• Setups ILI9341 display
• Fills the screen in polling
• Produces a bitmap
• Sends it over dma
• Produces another one and polls till dma is finished
• Repeats the cycle

You can freely modify or copy whatever you need.