stm32f103rct6 MAX6675 HAL库

以下是基于STM32 HAL库的STM32F103RCT6与MAX6675的代码示例：

#include "stm32f1xx_hal.h"

SPI_HandleTypeDef hspi1;

/* MAX6675 CS Pin */
#define MAX6675_CS_GPIO_PORT GPIOB
#define MAX6675_CS_GPIO_PIN GPIO_PIN_12

void SystemClock_Config(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();

  /* Initialize SPI */
  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_MASTER;
  hspi1.Init.Direction = SPI_DIRECTION_2LINES;
  hspi1.Init.DataSize = SPI_DATASIZE_16BIT;
  hspi1.Init.CLKPolarity = SPI_POLARITY_HIGH;
  hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;
  hspi1.Init.NSS = SPI_NSS_SOFT;
  hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_256;
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 10;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }

  /* Initialize MAX6675 CS Pin */
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  __HAL_RCC_GPIOB_CLK_ENABLE();
  GPIO_InitStruct.Pin = MAX6675_CS_GPIO_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(MAX6675_CS_GPIO_PORT, &GPIO_InitStruct);
  HAL_GPIO_WritePin(MAX6675_CS_GPIO_PORT, MAX6675_CS_GPIO_PIN, GPIO_PIN_SET);

  uint16_t data;
  float temperature;

  while (1)
  {
    /* Read temperature from MAX6675 */
    HAL_GPIO_WritePin(MAX6675_CS_GPIO_PORT, MAX6675_CS_GPIO_PIN, GPIO_PIN_RESET);
    HAL_SPI_Receive(&hspi1, &data, 1, HAL_MAX_DELAY);
    HAL_GPIO_WritePin(MAX6675_CS_GPIO_PORT, MAX6675_CS_GPIO_PIN, GPIO_PIN_SET);

    /* Convert data to temperature */
    temperature = (float)data * 0.25f;

    /* Do something with temperature */
  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

在此代码示例中，使用SPI1与MAX6675进行通信。首先，初始化了SPI1，并设置了CS引脚为输出模式。然后在主循环中，通过SPI1从MAX6675读取温度数据，并转换成温度值。最后可以将温度值用于其他操作。

需要注意的是，此代码示例中的时钟配置适用于8MHz的外部晶振，并使用PLL倍频到72MHz。如果使用其他时钟配置，需要相应更改代码。另外，此代码示例中的SPI时钟分频系数为256，这意味着SPI时钟为72MHz/256=281.25kHz。如果需要更高的SPI时钟速度，可以将分频系数更改为较小的值。