stm32 电阻检测 程序 接法 hal

电阻检测可以采用STM32内置的ADC模块进行实现，具体步骤如下：

1. 配置ADC模块的通道和采样时间

ADC_ChannelConfTypeDef sConfig = {0};
sConfig.Channel = ADC_CHANNEL_0;  // 选择ADC通道0进行采集
sConfig.Rank = 1;
sConfig.SamplingTime = ADC_SAMPLETIME_13CYCLES_5;  // 采样时间为13个周期
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
  Error_Handler();
}

2. 启动ADC转换

if (HAL_ADC_Start(&hadc1) != HAL_OK)
{
  Error_Handler();
}

3. 等待转换完成，并读取ADC值

if (HAL_ADC_PollForConversion(&hadc1, 100) != HAL_OK)  // 等待100ms
{
  Error_Handler();
}
uint16_t adc_value = HAL_ADC_GetValue(&hadc1);  // 读取ADC转换值

4. 根据电阻分压原理计算电阻值

float r1 = 10000.0;  // 电阻分压电阻1
float r2 = 10000.0;  // 电阻分压电阻2
float vref = 3.3;  // 参考电压
float vadc = (float)adc_value / 4096.0 * vref;  // 计算ADC输入电压
float r = r2 * (vref / vadc - 1.0);  // 计算电阻值

完整代码示例如下：

#include "main.h"
#include "stm32f1xx_hal.h"

ADC_HandleTypeDef hadc1;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_ADC1_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_ADC1_Init();

  while (1)
  {
    if (HAL_ADC_Start(&hadc1) != HAL_OK)
    {
      Error_Handler();
    }
    if (HAL_ADC_PollForConversion(&hadc1, 100) != HAL_OK)
    {
      Error_Handler();
    }
    uint16_t adc_value = HAL_ADC_GetValue(&hadc1);
    float r1 = 10000.0;
    float r2 = 10000.0;
    float vref = 3.3;
    float vadc = (float)adc_value / 4096.0 * vref;
    float r = r2 * (vref / vadc - 1.0);
    printf("R=%.2f\n", r);
    HAL_Delay(1000);
  }
}

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

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  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();
  }

  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();
  }

  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC;
  PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV6;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_ADC1_Init(void)
{
  ADC_ChannelConfTypeDef sConfig = {0};

  hadc1.Instance = ADC1;
  hadc1.Init.ScanConvMode = DISABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc1.Init.NbrOfConversion = 1;
  if (HAL_ADC_Init(&hadc1) != HAL_OK)
  {
    Error_Handler();
  }

  sConfig.Channel = ADC_CHANNEL_0;
  sConfig.Rank = 1;
  sConfig.SamplingTime = ADC_SAMPLETIME_13CYCLES_5;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_GPIO_Init(void)
{
  __HAL_RCC_GPIOC_CLK_ENABLE();

  GPIO_InitTypeDef GPIO_InitStruct = {0};

  GPIO_InitStruct.Pin = GPIO_PIN_13;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
}

void Error_Handler(void)
{
  while (1)
  {
    HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET);
    HAL_Delay(1000);
    HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_SET);
    HAL_Delay(1000);
  }
}

该程序使用的是STM32CubeMX和HAL库进行开发，通过ADC读取电阻值并在串口输出。注意需要将PA0引脚连接到待测电阻的一端，另一端连接到GND。