stm32平衡小车程序讲解

STM32平衡小车是一种基于STM32微控制器的自主移动设备，通常使用陀螺仪、加速度计和磁力计等传感器来检测其运动状态。下面是一个简单的STM32平衡小车程序讲解：

1. 初始化I/O口：首先需要配置STM32的GPIO端口，用于连接小车的各个硬件模块，如电机驱动器、电池等。例如，将PA0-PA3引脚设置为输出模式，用于控制三个电机的正转和反转。

```c

void SystemInit(void) {

RCC->APB2ENR |= RCC_APB2ENR_GPIOAEN; // Enable GPIOA clock

GPIOA->MODER &= ~(3 << 16); // Set PA0-PA3 as output

}

```

2. 初始化时钟：配置STM32的系统时钟，以便为后续的定时器和中断服务提供准确的时间基准。例如，使用HSE（高速外部振荡器）作为时钟源，并设置系统时钟为72MHz。

```c

void SystemClockUpdate(void) {

RCC->CR |= RCC_CR_HSEON; // Enable HSE oscillator

RCC->CR |= RCC_CR_HSI148ON; // Enable HSI148 oscillator

RCC->SYSCLKCR = (RCC->SYSCLKCR & ~(RCC_SYSCLKCR_HSEBYP | RCC_SYSCLKCR_PLLM)) | RCC_SYSCLKCR_PLL4; // Set PLL configuration

RCC->PLL1DIVR = 1; // Set PLL1 division ratio to 1, corresponding to a frequency of 72 MHz for the system clock

RCC->CR |= RCC_CR_PLL1ON; // Enable PLL1

while ((RCC->CR & RCC_CR_PLL1RDY) != RCC_CR_PLL1RDY); // Wait until PLL1 is ready

RCC->SYSCLKCR |= RCC_SYSCLKCR_SWS_HSE; // Set system clock source to HSE

while ((RCC->SYSCLKCR & RCC_SYSCLKCR_SWS) != RCC_SYSCLKCR_SWS_HSE); // Wait until system clock source is changed to HSE

}

```

3. 初始化GPIO：根据小车的硬件连接图，配置相应的GPIO引脚为输入或输出模式，并配置为上升沿触发的中断。

```c

void GPIO_Configuration(void) {

// Connect sensors to GPIO ports

GPIO_InitTypeDef GPIO_InitStruct = {0};

GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3; // Connect sensors to PA0-PA3

GPIO_InitStruct.Mode = GPIO_MODE_AF; // Set as alternate function

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW; // Low frequency

GPIO_InitStruct.Alternate = GPIO_AF_INTT; // Set as interrupt input

HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

NVIC_InitTypeDef NVIC_InitStruct = {0};

NVIC_InitStruct.NVIC_IRQChannel = EXTI9_5_IRQn; // Configure IRQ channel for EXTI9_5 pin

NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;

NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; // Enable external interrupt

HAL_NVIC_Init(&NVIC_InitStruct);

}

```

4. 初始化DMA：配置DMA通道，以便从外设（如陀螺仪）读取数据并将其传输到内存中。

```c

void DMA_Configuration(void) {

DMA_InitTypeDef DMA_InitStruct = {0};

/* Set DMA1_Channel5 as configuration */

DMA_InitStruct.DMA_Channel = DMA_CHANNEL_5;

DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t)(&(HSI48_OCTOSEQ->R);); // Set peripheral base address

DMA_InitStruct.DMA_MemoryBaseAddr = (uint32_t)(&(dma_buffer[0])); // Set memory base address

DMA_InitStruct.DMA_PERC_CNT = DMA_PCC_EN1; // Set peripheral count to 1

DMA_InitStruct.DMA_MEMC_CNT = DMA_MCC_EN1; // Set memory count to 1

DMA_InitStruct.DMA_Mode = DMA_NORMAL; // Set normal mode

DMA_InitStruct.DMA_Priority = DMA_PRIORITY_HIGH; // Set high priority

DMA_InitStruct.DMA_FIFO_Threshold = DMA_FIFO_THRESHOLD_HALFFULL; // Set FIFO threshold to half full

DMA_InitStruct.DMA_FIFO_Direction = DMA_FIFO_RESET; // Reset FIFO

DMA_Init(&DMA_InitStruct);

}

```

5. 初始化EXTI：配置EXTI（外部中断/事件）线路，以便在检测到特定事件（如陀螺仪数据到达）时触发中断。

```c

void EXTI_Configuration(void) {

EXTI_InitTypeDef EXTI_InitStruct = {0};

EXTI_InitStruct.EXTI_Line = EXTI_LINE_9; // Connect sensor to EXTI Line 9

EXTI_InitStruct.EXTI_Mode = EXTI_MODE_IT; // Set as interrupt mode

EXTI_InitStruct.EXTI_Trigger = EXTI_TRIGGER_RISING_EDGE; // Set as rising edge trigger

EXTI_InitStruct.EXTI_Filter = EXTI_FILTER_FIRST_TRANSMITTED; // Remove DC bias from input signal

HAL_EXTI_Init(&EXTI_InitStruct);

}

```

6. 中断服务程序：当检测到特定事件时，执行相应的操作，如读取传感器数据、控制电机等。

```c

void EXTI9_5_IRQHandler(void) {

if (EXTI->PR == EXTI_PR_PR9) { // Check if an event has been generated on EXTI Line 9

HAL_GPIO_ReadInputDataBit(GPIOA, GPIO_PIN_0); // Read data from sensor

// Process sensor data and control motors based on the results...

}

}

```

以上就是一个简单的STM32平衡小车程序的讲解。实际应用中可能需要根据具体的硬件配置和需求进行调整。