GPIO_InitTypeDef GPIO_InitStruct = 0; GPIO_InitStruct.Pin = GPIO_PIN_13; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_NOPULL; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW; HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

HAL_Init(); SystemClock_Config(); // generated by CubeMX __HAL_RCC_GPIOC_CLK_ENABLE();

if(GPIO_Pin == GPIO_PIN_0) // button pressed

Abstract The STM32 family of 32-bit ARM Cortex-M microcontrollers from STMicroelectronics has become a dominant platform in embedded systems due to its performance, power efficiency, and extensive peripheral set. This paper provides a complete overview of programming STM32 devices, covering development environments, hardware abstraction layers, low-level register programming, and practical examples. We compare major toolchains (STM32CubeIDE, Keil MDK, IAR EWARM), explain the role of the Hardware Abstraction Layer (HAL) and Low-Layer (LL) APIs, and demonstrate basic peripheral control (GPIO, timers, USART). The paper concludes with best practices for debugging and optimization.

UART_HandleTypeDef huart2; huart2.Instance = USART2; huart2.Init.BaudRate = 115200; huart2.Init.WordLength = UART_WORDLENGTH_8B; huart2.Init.StopBits = UART_STOPBITS_1; huart2.Init.Parity = UART_PARITY_NONE; huart2.Init.Mode = UART_MODE_TX_RX; HAL_UART_Init(&huart2); char msg[] = "Hello STM32\r\n"; HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY); The Nested Vectored Interrupt Controller (NVIC) handles prioritized interrupts.

CC = arm-none-eabi-gcc CFLAGS = -mcpu=cortex-m3 -mthumb -Os -ffunction-sections -fdata-sections LDFLAGS = -Wl,--gc-sections -T STM32F103C8Tx_FLASH.ld SRCS = main.c system_stm32f1xx.c OBJS = $(SRCS:.c=.o) all: firmware.elf firmware.elf: $(OBJS) $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ flash: firmware.elf openocd -f interface/stlink.cfg -f target/stm32f1x.cfg -c "program $< verify reset exit" Paper completed – suitable for undergraduate embedded systems coursework or professional reference.