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STM32内部参考电压+DMA精准采集电池电压

程序员文章站 2022-03-18 10:06:12
最近项目又遇到了电池电压采集，锂电池的电压范围是4.2到2.8一般，当锂电池低于3.3V时，单片机供电电压会小于3.3V，那么电池电压参考计算4096就不能对应3.3,所以必须采用内部参考电压。（我项目中用到的是RP104N331 LDO，实际上当电池电压在3.5V左右时，LDO输出就已经不是3.3V，严重影响精度）VREFINT_CAL = *(__IO uint16_t *)(0X1FF80078);首先需要从数据手册知道VREFINT_CAL 的地址信息，读出16的值，所以这里采用了 uint1...

最近项目又遇到了电池电压采集，锂电池的电压范围是4.2到2.8一般，当锂电池低于3.3V时，单片机供电电压会小于3.3V，那么电池电压参考计算4096就不能对应3.3,所以必须采用内部参考电压。（我项目中用到的是RP104N331 LDO，实际上当电池电压在3.5V左右时，LDO输出就已经不是3.3V，严重影响精度）

VREFINT_CAL = *(__IO uint16_t *)(0X1FF80078);

首先需要从数据手册知道VREFINT_CAL 的地址信息，读出16的值，所以这里采用了 uint16_t
同时stm32 开启两路ADC，一路是要采集的ADC，一路是内部参考电压

	ADC_ChannelConfTypeDef sConfig = {0};
	VREFINT_CAL = *(__IO uint16_t *)(0X1FF80078);
	V_temp1 = 3.3 / 4096 * (float)ADC_buffer[0] / 0.6;
	VDDA = 3 * VREFINT_CAL/(float)ADC_buffer[1];
	V_temp2 = VDDA/4096 * (float)ADC_buffer[0] / 0.6;
	printf("VDDA %f \r\n",VDDA);
	printf("%f V %f V\r\n",V_temp1,V_temp2);
	printf("%d %d\r\n",ADC_buffer[0],ADC_buffer[1]);

V1是常规的3.3V作为参考电压，VDDA可以通过VREFINT_CAL 计算得出，V_temp2是以VDDA得出，经过开关电源测试，V_temp2误差基本保持在0.01V

由于我们采集双通道，所以采用DMA传输

这里有几个参数需要注意，一个是ClockPrescaler，我这里采用ADC_CLOCK_ASYNC_DIV128，分频不同居然采集的电压不同，而且误差极大，这里一直找不到相关原因，另一个是LowPowerFrequencyMode，由于这里分频比较大，导致采用时钟很低，所以ENABLE，具体低于多少打开手册有要求，但是实测使能或者不使能差别并不是很大，最后在初始化完成之后需要增加校准函数HAL_ADCEx_Calibration_Start

下面是adc.c源码,这里的DMA是连续采集，只需在主函数开启一次HAL_ADC_Start_DMA(&hadc, (uint32_t *)ADC_buffer, 2)

/**
  ******************************************************************************
  * File Name          : ADC.c
  * Description        : This file provides code for the configuration
  *                      of the ADC instances.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 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
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "adc.h"

/* USER CODE BEGIN 0 */
__IO uint32_t uwADCxConvertedValue1 = 0;
__IO uint32_t uwADCxConvertedValue2 = 0;
__IO uint16_t VREFINT_CAL ;
float V_temp1,V_temp2,VDDA;
extern uint32_t ADC_buffer[2];
/* USER CODE END 0 */

ADC_HandleTypeDef hadc;
DMA_HandleTypeDef hdma_adc;

/* ADC init function */
void MX_ADC_Init(void)
{
  ADC_ChannelConfTypeDef sConfig = {0};

  /** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion) 
  */
  hadc.Instance = ADC1;
  hadc.Init.OversamplingMode = DISABLE;
  hadc.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV128;
  hadc.Init.Resolution = ADC_RESOLUTION_12B;
  hadc.Init.SamplingTime = ADC_SAMPLETIME_12CYCLES_5;
  hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
  hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc.Init.ContinuousConvMode = ENABLE;
  hadc.Init.DiscontinuousConvMode = DISABLE;
  hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc.Init.DMAContinuousRequests = ENABLE;
  hadc.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  hadc.Init.Overrun = ADC_OVR_DATA_PRESERVED;
  hadc.Init.LowPowerAutoWait = DISABLE;
  hadc.Init.LowPowerFrequencyMode = ENABLE;
  hadc.Init.LowPowerAutoPowerOff = DISABLE;
  if (HAL_ADC_Init(&hadc) != HAL_OK)
  {
    Error_Handler();
  }
	
	if (HAL_ADCEx_Calibration_Start(&hadc, ADC_SINGLE_ENDED) !=  HAL_OK)
		{
    Error_Handler();
		}
  /** Configure for the selected ADC regular channel to be converted. 
  */
  sConfig.Channel = ADC_CHANNEL_1;
  sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
  if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /** Configure for the selected ADC regular channel to be converted. 
  */
  sConfig.Channel = ADC_CHANNEL_VREFINT;
  if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

}

void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(adcHandle->Instance==ADC1)
  {
  /* USER CODE BEGIN ADC1_MspInit 0 */

  /* USER CODE END ADC1_MspInit 0 */
    /* ADC1 clock enable */
    __HAL_RCC_ADC1_CLK_ENABLE();
  
    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**ADC GPIO Configuration    
    PA1     ------> ADC_IN1 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_1;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* ADC1 DMA Init */
    /* ADC Init */
    hdma_adc.Instance = DMA1_Channel1;
    hdma_adc.Init.Request = DMA_REQUEST_0;
    hdma_adc.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_adc.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_adc.Init.MemInc = DMA_MINC_ENABLE;
    hdma_adc.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
    hdma_adc.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
    hdma_adc.Init.Mode = DMA_CIRCULAR;
    hdma_adc.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_adc) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(adcHandle,DMA_Handle,hdma_adc);

  /* USER CODE BEGIN ADC1_MspInit 1 */
//		if (HAL_ADCEx_Calibration_Start(&hadc, ADC_SINGLE_ENDED) !=  HAL_OK)
//		{
//    Error_Handler();
//		}
  /* USER CODE END ADC1_MspInit 1 */
  }
}

void HAL_ADC_MspDeInit(ADC_HandleTypeDef* adcHandle)
{

  if(adcHandle->Instance==ADC1)
  {
  /* USER CODE BEGIN ADC1_MspDeInit 0 */

  /* USER CODE END ADC1_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_ADC1_CLK_DISABLE();
  
    /**ADC GPIO Configuration    
    PA1     ------> ADC_IN1 
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_1);

    /* ADC1 DMA DeInit */
    HAL_DMA_DeInit(adcHandle->DMA_Handle);
  /* USER CODE BEGIN ADC1_MspDeInit 1 */

  /* USER CODE END ADC1_MspDeInit 1 */
  }
} 

/* USER CODE BEGIN 1 */
void Acquisition_voltage()
{
	//float VDDA;
	ADC_ChannelConfTypeDef sConfig = {0};
	VREFINT_CAL = *(__IO uint16_t *)(0X1FF80078);
	V_temp1 = 3.3 / 4096 * (float)ADC_buffer[0] / 0.6;
	VDDA = 3 * VREFINT_CAL/(float)ADC_buffer[1];
	V_temp2 = VDDA/4096 * (float)ADC_buffer[0] / 0.6;
	printf("VDDA %f \r\n",VDDA);
	printf("%f V %f V\r\n",V_temp1,V_temp2);
	printf("%d %d\r\n",ADC_buffer[0],ADC_buffer[1]);
  
	
//	//printf("VREFINT_CAL %d \r\n",VREFINT_CAL);
	
	sConfig.Channel = ADC_CHANNEL_1;
  sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
  if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
//	
//	
//	if (HAL_ADC_Start(&hadc) != HAL_OK)
//  {
//    /* Start Conversation Error */
//    Error_Handler();
//  }
//	
//   HAL_ADC_PollForConversion(&hadc, 1000);
//  
//	/* Check if the continous conversion of regular channel is finished */
//	if ((HAL_ADC_GetState(&hadc) & HAL_ADC_STATE_REG_EOC) == HAL_ADC_STATE_REG_EOC)
//	{
//		/*##-6- Get the converted value of regular channel  ########################*/
//		uwADCxConvertedValue1 = HAL_ADC_GetValue(&hadc);
//		
//	}
//	
	printf("uwADCxConvertedValue1 %d\r\n",uwADCxConvertedValue1);
//	V_temp = 3.3 / 4096 * uwADCxConvertedValue1 / 0.6;
//	printf("V_temp %f V\r\n",V_temp);

	sConfig.Channel = ADC_CHANNEL_17;
  sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
  if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
//	
//	
//	if (HAL_ADC_Start(&hadc) != HAL_OK)
//  {
//    /* Start Conversation Error */
//    Error_Handler();
//  }
//	
//   HAL_ADC_PollForConversion(&hadc, 1000);
//  
//	/* Check if the continous conversion of regular channel is finished */
//	if ((HAL_ADC_GetState(&hadc) & HAL_ADC_STATE_REG_EOC) == HAL_ADC_STATE_REG_EOC)
//	{
//		/*##-6- Get the converted value of regular channel  ########################*/
//		uwADCxConvertedValue2 = HAL_ADC_GetValue(&hadc);
//	}
//	
//	printf("uwADCxConvertedValue2 %d\r\n",uwADCxConvertedValue2);
	
	
	
}
/* USER CODE END 1 */

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

本文地址：https://blog.csdn.net/qq_36097683/article/details/108580900

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