STM32模拟SPI协议控制数字电位器MCP41010电阻值
MCP41010是单路8位分辨率数字电位器,通过SPI接口可控制电位器阻值分配,相当于PW0端在PA0和PB0之间滑动。如下图所示:
 
 MCP41010是10K欧姆规格的数字电位器,即PA0和PB0之间的阻值恒定为10K,PW0与PA0或PW0与PB0之间的阻值互补可配。
 另外有相关型号不同阻值规格和集成双路的MCP系列数字电位器,其控制原理相同:
 
 这里介绍STM32模拟SPI协议控制数字电位器MCP41010的代码范例。采用STM32CUBEIDE开发平台,以STM32F401RCT6为例。
STM32工程配置
首先建立基本工程并设置时钟:
 
 采用内部时钟源即可:
 
配置3个GPIO作为模拟SPI的管脚:
 
 保存并生成初始工程代码:
 
STM32工程代码
代码里用到的微秒延时函数参考: STM32 HAL us delay(微秒延时)的指令延时实现方式及优化
代码的实现功能为每隔5秒将阻值从低值,中值和高值进行转变,用万用表即可测试阻值验证。
建立MCP41010.h头文件:
#ifndef INC_MCP41010_H_
#define INC_MCP41010_H_
#include "main.h"
void PY_Delay_us_t(uint32_t Delay);
void MCP41010_Init(void);
void MCP41010_SHUTDONW(void);
void MCP41010_Write(uint8_t data);
#endif /* INC_MCP41010_H_ */
建立MCP41010.c源文件:
#include "MCP41010.h"
#define   MCP41010_CS_L             HAL_GPIO_WritePin(GPIOB, GPIO_PIN_0, GPIO_PIN_RESET)
#define   MCP4101_CS_H              HAL_GPIO_WritePin(GPIOB, GPIO_PIN_0, GPIO_PIN_SET)
#define   MCP4101_SCK_L             HAL_GPIO_WritePin(GPIOB, GPIO_PIN_1, GPIO_PIN_RESET)
#define   MCP4101_SCK_H             HAL_GPIO_WritePin(GPIOB, GPIO_PIN_1, GPIO_PIN_SET)
#define   MCP4101_SI_L              HAL_GPIO_WritePin(GPIOB, GPIO_PIN_2, GPIO_PIN_RESET)
#define   MCP4101_SI_H              HAL_GPIO_WritePin(GPIOB, GPIO_PIN_2, GPIO_PIN_SET)
#define SPI_Delay_us 2
void MCP41010_Init(void)
{
	MCP4101_CS_H;
}
void MCP41010_SHUTDONW(void)
{
	 uint16_t MD=0x2100;
	    MCP41010_CS_L;PY_Delay_us_t(SPI_Delay_us);
	    for(uint8_t i=0;i<16;i++)
		{
		    MCP4101_SCK_L;
			if(MD&0x8000){MCP4101_SI_H;}
			else {MCP4101_SI_L;}
			PY_Delay_us_t(SPI_Delay_us);
			MCP4101_SCK_H;
			MD<<=1;
			PY_Delay_us_t(SPI_Delay_us);
		}
	    MCP4101_SCK_L;
	    PY_Delay_us_t(SPI_Delay_us);
	    MCP4101_CS_H ;
}
void MCP41010_Write(uint8_t data)
{
    uint16_t MD=0x1100;
    MD |= data;
    MCP41010_CS_L;PY_Delay_us_t(SPI_Delay_us);
    for(uint8_t i=0;i<16;i++)
	{
	    MCP4101_SCK_L;
		if(MD&0x8000){MCP4101_SI_H;}
		else {MCP4101_SI_L;}
		PY_Delay_us_t(SPI_Delay_us);
		MCP4101_SCK_H;
		MD<<=1;
		PY_Delay_us_t(SPI_Delay_us);
	}
    MCP4101_SCK_L;
    PY_Delay_us_t(SPI_Delay_us);
    MCP4101_CS_H ;
}
main.c文件里实现测试功能:
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2023 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "MCP41010.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
__IO float usDelayBase;
void PY_usDelayTest(void)
{
  __IO uint32_t firstms, secondms;
  __IO uint32_t counter = 0;
  firstms = HAL_GetTick()+1;
  secondms = firstms+1;
  while(uwTick!=firstms) ;
  while(uwTick!=secondms) counter++;
  usDelayBase = ((float)counter)/1000;
}
void PY_Delay_us_t(uint32_t Delay)
{
  __IO uint32_t delayReg;
  __IO uint32_t usNum = (uint32_t)(Delay*usDelayBase);
  delayReg = 0;
  while(delayReg!=usNum) delayReg++;
}
void PY_usDelayOptimize(void)
{
  __IO uint32_t firstms, secondms;
  __IO float coe = 1.0;
  firstms = HAL_GetTick();
  PY_Delay_us_t(1000000) ;
  secondms = HAL_GetTick();
  coe = ((float)1000)/(secondms-firstms);
  usDelayBase = coe*usDelayBase;
}
void PY_Delay_us(uint32_t Delay)
{
  __IO uint32_t delayReg;
  __IO uint32_t msNum = Delay/1000;
  __IO uint32_t usNum = (uint32_t)((Delay%1000)*usDelayBase);
  if(msNum>0) HAL_Delay(msNum);
  delayReg = 0;
  while(delayReg!=usNum) delayReg++;
}
/* 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);
static void MX_GPIO_Init(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();
  /* USER CODE BEGIN 2 */
  PY_usDelayTest();
  PY_usDelayOptimize();
  MCP41010_Init();
  /* USER CODE END 2 */
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	  MCP41010_Write(0x01);
	  PY_Delay_us_t(5000000);
	  MCP41010_Write(0x80);
	  PY_Delay_us_t(5000000);
	  MCP41010_Write(0xFF);
	  PY_Delay_us_t(5000000);
    /* USER CODE END WHILE */
    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}
/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  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 = 16;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  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();
  }
}
/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOB_CLK_ENABLE();
  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_0, GPIO_PIN_SET);
  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_1|GPIO_PIN_2, GPIO_PIN_RESET);
  /*Configure GPIO pins : PB0 PB1 PB2 */
  GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* 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 */
STM32例程下载
STM32F401模拟SPI协议控制数字电位器MCP41010电阻值例程
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