蓝桥杯嵌入式（STM32G431RBT6）入门第六天——模数转换（ADC）｜CSDN创作打卡

今天需要拷贝一份赛点资源包里面提供的液晶驱动例程，并修改名称为ADC练习。

 

下面简单介绍一下ADC：

量程：指ADC所能输入模拟信号的类型和电压范围，即参考电压。信号类型包括单极性和双极性，蓝桥杯嵌入式G431开发板的输入电压范围是0~3.3V。

转换位数：量化过程中的量化位数n。蓝桥杯嵌入式G431开发板我习惯使用的位数是12位。

分辨率：ADC能够分辨的模拟信号最小变化量。

公式：分辨率 = 量程/

则蓝桥杯嵌入式G431开发板的分辨率就是3.3/4096 = 0.0008056

接着来看原理图部分：

 蓝桥杯嵌入式G431开发板上有两个比赛会考的ADC，分别接在PB15和PB12口，通过调节可调电阻让开发板读取到不同的电压并在屏幕上显示。

下面直接用STM32CubeMX打开拷贝过来的HAL_06_LCD.ioc文件进入到配置界面。

 点击PB12就可以直接配置为ADC1的11通道，同样点击PB15可以直接选择配置为ADC2的15通道。

点击Analog找到ADC1的通道11，按照图中进行配置，⑤为12位数据，⑥为右对齐，⑦为采样时间，时间越长数据越精确，时间越短数据质量越低。

 同样对ADC2的15通道进行相同的配置，完成后设置一下工程即可重新生成代码。下面附上编写完成的main代码，其中：

HAL_ADC_Start(&hadc1);为ADC启动函数

HAL_ADC_PollForConversion(&hadc1, 2);设置通道和采集超时时间
adc = HAL_ADC_GetValue(&hadc1);获取采样值
HAL_ADC_Stop(&hadc1);采样完成后停止，降低功耗

使用到了sprintf函数，如果不太了解的话可以去学习一下。

#include "main.h"
#include "adc.h"
#include "gpio.h"
#include "stdio.h"

void SystemClock_Config(void);

uint16_t R38_GET(void)
{
	uint16_t adc=0;
	
	HAL_ADC_Start(&hadc1);
	HAL_ADC_PollForConversion(&hadc1, 2);
	adc = HAL_ADC_GetValue(&hadc1);
	HAL_ADC_Stop(&hadc1);
	return adc;
}

uint16_t R37_GET(void)
{
	uint16_t adc=0;
	
	HAL_ADC_Start(&hadc2);
	HAL_ADC_PollForConversion(&hadc2, 2);
	adc = HAL_ADC_GetValue(&hadc2);
	HAL_ADC_Stop(&hadc2);
	return adc;
}

int main(void)
{

	char str[64];
 
  HAL_Init();

  SystemClock_Config();

  MX_GPIO_Init();
  MX_ADC1_Init();
  MX_ADC2_Init();
	
	LCD_Init();
	
	LCD_Clear(Black);
	LCD_SetBackColor(Black);
	LCD_SetTextColor(White);
	LCD_DisplayStringLine(Line3,(unsigned char *)"      LCD TEST      ");	
	LCD_DisplayStringLine(Line1,(unsigned char *)"                    ");	
	LCD_DisplayStringLine(Line2,(unsigned char *)"                    ");
	LCD_DisplayStringLine(Line0,(unsigned char *)"                    ");
	LCD_DisplayStringLine(Line4,(unsigned char *)"                    ");					
	LCD_DisplayStringLine(Line5,(unsigned char *)"                    ");
	LCD_DisplayStringLine(Line6,(unsigned char *)"                    ");
	LCD_DisplayStringLine(Line7,(unsigned char *)"                    ");	
	LCD_DisplayStringLine(Line8,(unsigned char *)"                    ");
	LCD_DisplayStringLine(Line9,(unsigned char *)"                    ");	
	
  while (1)
  {
		sprintf((char *)str, "    R37: %.2f", R37_GET()*3.3/4096);
		LCD_DisplayStringLine(Line6,(unsigned char *)str);
		HAL_Delay(100);
		
		sprintf((char *)str, "    R38: %.2f", R38_GET()*3.3/4096);
		LCD_DisplayStringLine(Line7,(unsigned char *)str);
		HAL_Delay(100);
  }
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};

  /** Configure the main internal regulator output voltage
  */
  HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
  /** Initializes the CPU, AHB and APB busses clocks
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV2;
  RCC_OscInitStruct.PLL.PLLN = 20;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB busses 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_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the peripherals clocks
  */
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC12;
  PeriphClkInit.Adc12ClockSelection = RCC_ADC12CLKSOURCE_SYSCLK;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

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