【STM32G431RBTx】备战蓝桥杯嵌入式→扩展模块→DS18B20

前言

我们学完了AKEY的应用之后，就开始学习DS18B20的应用

一、软件准备

1、MDK4或者MDK5（可到官网或者其他途径获取，本人使用的是MDK5）
2、Cubemx（可到官网自行下载）
3、安装G4的包（1.2.0，1.3.0以及1.4.0均可）
4、串口调试助手（COM）

二、DS18B20

1.扩展板上模块的原理图以及我们需要配置的元素

DS18B20部分原理图:

模块在扩展板的布局:

分析:TDQ连接的是PA6,引脚，修改以及应用官方所给的驱动，就能实现用DS18B20对温度的采集。

2.CubeMx的配置步骤

RCC配置:略
设置调试接口:设置为Serial Wire
到此配置完成，不需要配置IO口。
生成工程:点击GENERATE CODE生成工程。

3.代码修改

将驱动包的文件名修改为ds18b20.h和ds18b20.c
之后按照下图修改即可:
ds18b20.h:

ds18b20.c:

在ds18b20.c中增加的读取函数:

三、测试代码

代码修改完成之后，添加lcd.h, lcd.c, fonts.h到工程中以方便显示。
ds18b20.h:

#ifndef __DS18B20_H //修改文件名之后这里也需要修改
#define __DS18B20_H

#include "main.h" //这里改为main.h

#define OW_PIN_PORT		    GPIOA
#define OW_PIN				GPIO_PIN_6


#define OW_DIR_OUT() 	    mode_output1()
#define OW_DIR_IN() 	    mode_input1()
#define OW_OUT_LOW() 	    (HAL_GPIO_WritePin(OW_PIN_PORT, OW_PIN, GPIO_PIN_RESET))
#define OW_GET_IN()  	    (HAL_GPIO_ReadPin(OW_PIN_PORT, OW_PIN))
#define OW_SKIP_ROM 		0xCC
#define DS18B20_CONVERT 	0x44
#define DS18B20_READ 		0xBE


void ds18b20_init_x(void);
float ds18b20_readT(void); //这里替换为自己的函数声明


#endif

ds18b20.c:

#include "ds18b20.h" //记得修改添加头文件的名称

#define delay_us(X)  delay((X)*100/5) //将80改为100，增大通讯的容错性

void delay(unsigned int n)
{
    while(n--);
}

void ds18b20_init_x(void)
{
    GPIO_InitTypeDef	GPIO_InitStruct = {0};

    /* GPIO Ports Clock Enable */
    __HAL_RCC_GPIOA_CLK_ENABLE();


    GPIO_InitStruct.Pin = OW_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH ;
    GPIO_InitStruct.Pull = GPIO_PULLUP ;
    HAL_GPIO_Init(OW_PIN_PORT, &GPIO_InitStruct);
}
//
void mode_input1(void )
{

    GPIO_InitTypeDef	GPIO_InitStruct = {0};

    /* GPIO Ports Clock Enable */

    GPIO_InitStruct.Pin = OW_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(OW_PIN_PORT, &GPIO_InitStruct);
}

void mode_output1(void )
{

    GPIO_InitTypeDef	GPIO_InitStruct = {0};

    GPIO_InitStruct.Pin = OW_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Pull = GPIO_NOPULL ;
    HAL_GPIO_Init(OW_PIN_PORT, &GPIO_InitStruct);
}

//
uint8_t ow_reset(void)
{
    uint8_t err;

    OW_DIR_OUT(); // pull OW-Pin low for 480us
    OW_OUT_LOW(); // disable internal pull-up (maybe on from parasite)

    delay_us(400);	  //about 480us

    // set Pin as input - wait for clients to pull low
    OW_DIR_IN(); // input

    delay_us(66);
    err = OW_GET_IN();		// no presence detect
    // nobody pulled to low, still high


    // after a delay the clients should release the line
    // and input-pin gets back to high due to pull-up-resistor
    delay_us(480 - 66);
    if( OW_GET_IN() == 0 )		// short circuit
        err = 1;

    return err;
}

uint8_t ow_bit_io( uint8_t b )
{
    OW_DIR_OUT(); // drive bus low
    OW_OUT_LOW();
    delay_us(1); // Recovery-Time wuffwuff was 1

    if ( b ) OW_DIR_IN(); // if bit is 1 set bus high (by ext. pull-up)

#define  OW_CONF_DELAYOFFSET  5
    delay_us(15 - 1 - OW_CONF_DELAYOFFSET);

    if( OW_GET_IN() == 0 ) b = 0;  // sample at end of read-timeslot

    delay_us(60 - 15);
    OW_DIR_IN();

    return b;
}

uint8_t ow_byte_wr( uint8_t b )
{
    uint8_t i = 8, j;
    do
    {
        j = ow_bit_io( b & 1 );
        b >>= 1;
        if( j ) b |= 0x80;
    }
    while( --i );
    return b;
}

//
uint8_t ow_byte_rd( void )
{
    return ow_byte_wr( 0xFF );
}

float ds18b20_readT(void)
{
	unsigned char low, high;
	float temp;
	
	ow_reset(); //DS18B20开始转换
	ow_byte_wr(OW_SKIP_ROM);
	ow_byte_wr(DS18B20_CONVERT);
	
	ow_reset(); //开始读取DS18B20数据
	ow_byte_wr(OW_SKIP_ROM);
	ow_byte_wr(DS18B20_READ);
	
	low = ow_byte_rd();
	high = ow_byte_rd();
	temp = (high << 8 | low) * 0.0625; //转成实际温度
	
	return temp;
}

main.h:没有做修改所以不放出
main.c:

/* 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"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "ds18b20.h"
#include "lcd.h"
#include "stdio.h"
/* 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 */
unsigned int Ttick;
float T;
unsigned char should_read = 1;
/* 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();
  /* USER CODE BEGIN 2 */
	//等待DS18B20温度转换完成，防止插拔接口时产生的误读
	while((unsigned int)(ds18b20_readT()) == 85);
	LCD_Init();
	LCD_Clear(Black);
	LCD_SetBackColor(Black);
	LCD_SetTextColor(White);
  /* USER CODE END 2 */

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

    /* USER CODE BEGIN 3 */
		char text[30];
		T = ds18b20_readT();
		sprintf(text, "T:%.4f", T);
		LCD_DisplayStringLine(Line0, text);
  }
  /* 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_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);

  /** 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.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV3;
  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 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_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != 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 */

四、演示效果

五、工程链接

DS18B20工程模块

六、总结

以上就是DS18B20的配置过程，测试代码以及测试效果
以往的扩展板模块:
【STM32G431RBTx】备战蓝桥杯嵌入式→扩展模块→SEG
【STM32G431RBTx】备战蓝桥杯嵌入式→扩展模块→双路ADC/AO1, AO2
【STM32G431RBTx】备战蓝桥杯嵌入式→扩展模块→光敏电阻/TRAO, TRAO
【STM32G431RBTx】备战蓝桥杯嵌入式→扩展模块→AKEY