用ADC0831(串口)测电压,读回来一个8位的数据后(C程序),如何转换成实际电压值?

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还有它测量基准电压值有没上限?用10V行不行?

电压=(最大输入电压/0831的位数)×读回后的值
最大输入电压是你的设计电压比如5V,那么分成256份后就是0.02V,将读回后的值×0.02V就得到实际电压值了。若10V太高可采用电阻分压后得到,并且可以设计不同的分压电阻来切换档位。若要求较高可采用运放来完成0.1-N倍放大后即可。
参考技术A void covert(uchar x)

uchar code dispcode[]=0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f;
disp[0]=dispcode[x/50];
disp[0]=disp[0]+0x80;//加小数点
x=(x%50)*2;//得到小数部分
disp[1]=dispcode[x/10];//第一位小数
disp[2]=dispcode[x%10];//第二位小数


x/250=y/5->y=(5/250)x=x/50也就是说转换的数字量除以50就是实际电压值。
参考技术B 0~255 ----> 0.00 ~ 5.00

可以参考:
http://hi.baidu.com/%D7%F6%B6%F8%C2%DB%B5%C0/blog/item/738d6b23d0ccdde9d6cae2db.html

ADC值太高,端口串口读不出来

【中文标题】ADC值太高,端口串口读不出来【英文标题】:ADC value is so high and can't read it in port serial 【发布时间】:2021-08-05 14:48:00 【问题描述】:

您好,我使用 CubeMX 和 Hal lib 获得了 STM32F01C8T6 的这段代码:

  uint32_t value;
  while (1)
  
      HAL_ADC_Start (&hadc1);
      HAL_ADC_PollForConversion (&hadc1, 1000);
      value = HAL_ADC_GetValue (&hadc1);
      HAL_UART_Transmit (&huart1,value, 14, 50);
      HAL_ADC_Stop (&hadc1);
      HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);
      HAL_Delay(500);
  

ADC 输入为 3.3V,端口串口测试正常。

在调试模式下的值为:536880200,在端口串行中只打印像 !,d@)_+( 之类的坏词。

引脚和 ADC 配置: [1]:https://i.stack.imgur.com/YubLM.png

完整的 main.c 代码:

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2021 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "adc.h"
#include "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART1_UART_Init();
  MX_ADC1_Init();
  /* USER CODE BEGIN 2 */
  uint32_t value;
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
      HAL_ADC_Start (&hadc1);
      HAL_ADC_PollForConversion (&hadc1, 1000);
      value = HAL_ADC_GetValue (&hadc1);
      HAL_UART_Transmit (&huart1,value, 14, 50);
      HAL_ADC_Stop (&hadc1);
      HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);
      HAL_Delay(500);
  
  /* USER CODE END 3 */


/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)

  RCC_OscInitTypeDef RCC_OscInitStruct = 0;
  RCC_ClkInitTypeDef RCC_ClkInitStruct = 0;
  RCC_PeriphCLKInitTypeDef PeriphClkInit = 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();
  
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC;
  PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV6;
  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 */
  __disable_irq();
  while (1)
  
  
  /* 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,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */

#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

在调试模式下ADC值太高了,我无法在端口串行中读取它如何修复它?

谢谢。

【问题讨论】:

请阅读the help pages,接受SO tour,阅读How to Ask,以及this question checklist。最后请学习如何创建minimal reproducible example,重点是minimal部分。 常识:您的 ADC 分辨率是多少,考虑到该分辨率,值 536880200 是否有意义? 32 位 delta sigma 是相当罕见的野兽,我非常怀疑它会集成到您的 MCU 中。 【参考方案1】:

HAL_UART_Transmit的第二个参数是指向数据的指针,第三个是数据的大小。

如果要在 UART 上传输二进制数据,需要将 value, 14 更改为 &amp;value, sizeof value

如果您想传输 ASCII 文本,那么您需要执行以下操作:

char buffer[16];

int length = snprintf(buffer, sizeof buffer, "%u\n", (unsigned int)value);

if (length > 0)

  if (length >= sizeof buffer)
  
    length = ((sizeof buffer) - 1);
  

  HAL_UART_Transmit (&huart1, (uint8_t*)buffer, length, 50);

【讨论】:

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