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最终效果展示
AHT20温湿度传感器(I2C_AHT20)
通过I²C读取AHT20温湿度计
板载AHT20传感器规格:
学习板上的AHT20传感器:
- 编译并下载程序到学习板
- 使用配套TYPE-C数据线,将学习板连接到计算机
- 打开波特律动 串口助手 (keysking.com)在线串口调试助手,点击"选择串口",选择USB Single Serial
- 此时即可收到温湿度信息,如图所示
1、工程配置
- 打开I²C外设:Pinout&Configuration -> Connectivity -> I2C1,将I2C模式选择为I2C
- 打开串口2外设:Pinout&Configuration -> Connectivity -> USART2,将Mode选择为Asynchronous
- 配置工程:在Project Manager -> Code Generator页面中,勾选Generate peripheral initialization as ... per peripheral
2、代码
新建一个源文件和头文件
aht20.h
c
/*
* aht20.h
*
* Created on: Apr 25, 2024
* Author: lenovo
*/
#ifndef INC_AHT20_H_
#define INC_AHT20_H_
#include "i2c.h"
void AHT20_Init ();
void AHT20_Read(float *Temperature , float *Humidity);
#endif /* INC_AHT20_H_ */
aht20.c
c
#include "aht20.h"
#define AHT20_ADDRESS 0x70 // 从机地址
//AHT20 的驱动程序
void AHT20_Init () //AHT20初始化函数 记住要在"aht20.h"中声明
{
uint8_t readBuffer;//用于接收状态信息
HAL_Delay(40);
HAL_I2C_Master_Receive(&hi2c1, AHT20_ADDRESS, &readBuffer, 1, HAL_MAX_DELAY);//I2C读取函数,读数据函数 readBuffer此时获得了一个字节的状态字。
if((readBuffer & 0x08) == 0x00) //判断第三位是否为0 发送0xBE命令初始化
{
uint8_t sendBuffer [3] = {0xBE , 0x08 , 0x00};
HAL_I2C_Master_Transmit(&hi2c1, AHT20_ADDRESS, sendBuffer, 3, HAL_MAX_DELAY);//I2C发送函数
}
}
void AHT20_Read(float *Temperature , float *Humidity) //AHT20读取温度湿度函数 记住要在"aht20.h"中声明
{
uint8_t sendBuffer [3] = {0xAC , 0x33 , 0x00};
uint8_t readBuffer [6];
HAL_I2C_Master_Transmit(&hi2c1, AHT20_ADDRESS, sendBuffer, 3, HAL_MAX_DELAY);
HAL_Delay(75);
HAL_I2C_Master_Receive(&hi2c1, AHT20_ADDRESS, readBuffer, 6, HAL_MAX_DELAY);
if((readBuffer[0] & 0x80) == 0x00)
{
uint32_t date = 0;//接收温湿度需要2个半字节 所以要32
date = ((uint32_t )readBuffer[3] >> 4) + ((uint32_t )readBuffer[2] << 4) + ((uint32_t )readBuffer[1] << 12);//对数据进行移位拼接.
*Humidity = date * 100.0f / (1 << 20);//(1 << 20) 意为2的20次方. 乘100.0可以表示为百分数
date = (((uint32_t )readBuffer[3] & 0x0F)<< 16) + ((uint32_t )readBuffer[4] << 8) + (uint32_t )readBuffer[5];//& 0x0F: 将这个无符号整数与十六进制数0x0F进行按位与操作。0x0F的二进制表示为00001111,这个操作会保留readBuffer[3]的低四位,即将高四位清零。
*Temperature = date * 200.0f / (1 << 20) - 50;
}
}
main.c
c
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2024 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 "i2c.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "i2c.h"
#include <stdio.h>
#include "string.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 */
/* 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_I2C1_Init();
MX_USART2_UART_Init();
/* USER CODE BEGIN 2 */
AHT20_Init ();//初始化AHT20
float temperature , humidity ;
char message [50];
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
AHT20_Read( &temperature , &humidity); //读取AHT20
sprintf(message ,"温度: %.lf ℃ , 湿度: %.lf %%\r\n",temperature , humidity);//拼接
HAL_UART_Transmit(&huart2, (uint8_t*)message,strlen(message) , HAL_MAX_DELAY);//串口发�?�函�?
HAL_Delay(1000);
/* 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};
/** 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_NONE;
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_HSI;
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_0) != 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 */