目录
一、什么是软件I2C
二、什么是硬件I2C
三、STM32CubeMX配置
1、RCC配置
2、SYS配置
3、I2C1配置
3、I2C2配置
4、USART1配置
5、TIM1配置
6、时钟树配置
7、工程配置
四、设备链接
1、OLED连接
2、串口连接
3、温湿度传感器连接
五、每隔2秒钟采集一次温湿度数据，显示到OLED上，同时通过串口发送到上位机的“串口助手”软件
1、新建AHT20-21_DEMO_V1_3.c文件，代码如下
2、新建AHT20-21_DEMO_V1_3.h文件，代码如下
3、main.c文件
4、演示
参考链接
一、什么是软件I2C
软件I2C（也称为Bit-Banging I2C）是一种通过软件方法实现I2C通信协议的方式。在没有专用硬件I2C接口的微控制器或系统中，开发者可以通过编程直接控制通用的数字输入/输出（GPIO）引脚的电平变化，来模拟I2C总线的时序信号，包括启动条件、停止条件、应答位、数据位等。
二、什么是硬件I2C
硬件I2C是指微控制器或系统中集成的专用硬件模块，用于实现I2C（Inter-Integrated Circuit）通信协议。这个模块设计用来自动处理I2C总线的物理层和部分协议层的复杂时序，从而减轻主处理器（CPU）的负担并提高通信效率。
三、STM32CubeMX配置
1、RCC配置
2、SYS配置
3、I2C1配置
这里的I2C1用于连接AHT20温湿度传感器
3、I2C2配置
这里的I2C2用于连接OLED显示屏
4、USART1配置
这里的USART1连接串口
5、TIM1配置
6、时钟树配置
7、工程配置
四、设备链接
1、OLED连接
2、串口连接
3、温湿度传感器连接
五、每隔2秒钟采集一次温湿度数据，显示到OLED上，同时通过串口发送到上位机的“串口助手”软件
1、新建AHT20-21_DEMO_V1_3.c文件，代码如下
#include "main.h"
#include "AHT20-21_DEMO_V1_3.h"
#include "gpio.h"
#include "i2c.h"void Delay_N10us(uint32_t t)
{uint32_t k;while(t--){for (k = 0; k < 2; k++);//110}
}void SensorDelay_us(uint32_t t)
{for(t = t-2; t>0; t--){Delay_N10us(1);}
}void Delay_4us(void)
{ Delay_N10us(1);Delay_N10us(1);Delay_N10us(1);Delay_N10us(1);
}
void Delay_5us(void)
{ Delay_N10us(1);Delay_N10us(1);Delay_N10us(1);Delay_N10us(1);Delay_N10us(1);}void Delay_1ms(uint32_t t)
{while(t--){SensorDelay_us(1000);}
}//void AHT20_Clock_Init(void)
//{
// RCC_APB2PeriphClockCmd(CC_APB2Periph_GPIOB,ENABLE);
//}void SDA_Pin_Output_High(void)
{GPIO_InitTypeDef GPIO_InitStruct;GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pin = GPIO_PIN_7;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOB,& GPIO_InitStruct);HAL_GPIO_WritePin(GPIOB,GPIO_PIN_7,GPIO_PIN_SET);
}void SDA_Pin_Output_Low(void)
{GPIO_InitTypeDef GPIO_InitStruct;GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pin = GPIO_PIN_7;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOB,& GPIO_InitStruct);HAL_GPIO_WritePin(GPIOB,GPIO_PIN_7,GPIO_PIN_RESET);
}void SDA_Pin_IN_FLOATING(void)
{GPIO_InitTypeDef GPIO_InitStruct;GPIO_InitStruct.Mode = GPIO_MODE_INPUT;GPIO_InitStruct.Pin = GPIO_PIN_7;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init( GPIOB,&GPIO_InitStruct);
}void SCL_Pin_Output_High(void)
{HAL_GPIO_WritePin(GPIOB,GPIO_PIN_6,GPIO_PIN_SET);
}void SCL_Pin_Output_Low(void)
{HAL_GPIO_WritePin(GPIOB,GPIO_PIN_6,GPIO_PIN_RESET);
}void Init_I2C_Sensor_Port(void)
{ GPIO_InitTypeDef GPIO_InitStruct;GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pin = GPIO_PIN_7;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOB,& GPIO_InitStruct);HAL_GPIO_WritePin(GPIOB,GPIO_PIN_7,GPIO_PIN_SET);GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pin = GPIO_PIN_6;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOB,& GPIO_InitStruct);HAL_GPIO_WritePin(GPIOB,GPIO_PIN_7,GPIO_PIN_SET);}
void I2C_Start(void)
{SDA_Pin_Output_High();SensorDelay_us(8);SCL_Pin_Output_High();SensorDelay_us(8);SDA_Pin_Output_Low();SensorDelay_us(8);SCL_Pin_Output_Low();SensorDelay_us(8);
}void AHT20_WR_Byte(uint8_t Byte)
{uint8_t Data,N,i; Data=Byte;i = 0x80;for(N=0;N<8;N++){SCL_Pin_Output_Low(); Delay_4us(); if(i&Data){SDA_Pin_Output_High();}else{SDA_Pin_Output_Low();} SCL_Pin_Output_High();Delay_4us();Data <<= 1;}SCL_Pin_Output_Low();SensorDelay_us(8); SDA_Pin_IN_FLOATING();SensorDelay_us(8);
} uint8_t AHT20_RD_Byte(void)
{uint8_t Byte,i,a;Byte = 0;SCL_Pin_Output_Low();SDA_Pin_IN_FLOATING();SensorDelay_us(8); for(i=0;i<8;i++){SCL_Pin_Output_High();Delay_5us();a=0;//if(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_15)) a=1;if(HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_7)) a=1;Byte = (Byte<<1)|a;//SCL_Pin_Output_Low();HAL_GPIO_WritePin(GPIOB,GPIO_PIN_6,GPIO_PIN_RESET);Delay_5us();}SDA_Pin_IN_FLOATING();SensorDelay_us(8); return Byte;
}uint8_t Receive_ACK(void)
{uint16_t CNT;CNT = 0;SCL_Pin_Output_Low(); SDA_Pin_IN_FLOATING();SensorDelay_us(8); SCL_Pin_Output_High(); SensorDelay_us(8); while((HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_7)) && CNT < 100) CNT++;if(CNT == 100){return 0;}SCL_Pin_Output_Low(); SensorDelay_us(8); return 1;
}void Send_ACK(void)
{SCL_Pin_Output_Low(); SensorDelay_us(8); SDA_Pin_Output_Low();SensorDelay_us(8); SCL_Pin_Output_High(); SensorDelay_us(8);SCL_Pin_Output_Low(); SensorDelay_us(8);SDA_Pin_IN_FLOATING();SensorDelay_us(8);
}void Send_NOT_ACK(void)
{SCL_Pin_Output_Low(); SensorDelay_us(8);SDA_Pin_Output_High();SensorDelay_us(8);SCL_Pin_Output_High(); SensorDelay_us(8); SCL_Pin_Output_Low(); SensorDelay_us(8);SDA_Pin_Output_Low();SensorDelay_us(8);
}void Stop_I2C(void)
{SDA_Pin_Output_Low();SensorDelay_us(8);SCL_Pin_Output_High(); SensorDelay_us(8);SDA_Pin_Output_High();SensorDelay_us(8);
}uint8_t AHT20_Read_Status(void)
{uint8_t Byte_first; I2C_Start();AHT20_WR_Byte(0x71);Receive_ACK();Byte_first = AHT20_RD_Byte();Send_NOT_ACK();Stop_I2C();return Byte_first;
}uint8_t AHT20_Read_Cal_Enable(void)
{uint8_t val = 0;//ret = 0,val = AHT20_Read_Status();if((val & 0x68)==0x08)return 1;else return 0;}void AHT20_SendAC(void)
{I2C_Start();AHT20_WR_Byte(0x70);Receive_ACK();AHT20_WR_Byte(0xac);Receive_ACK();AHT20_WR_Byte(0x33);Receive_ACK();AHT20_WR_Byte(0x00);Receive_ACK();Stop_I2C();}uint8_t Calc_CRC8(uint8_t *message,uint8_t Num)
{uint8_t i;uint8_t byte;uint8_t crc=0xFF;for(byte=0; byte<Num; byte++){crc^=(message[byte]);for(i=8;i>0;--i){if(crc&0x80) crc=(crc<<1)^0x31;else crc=(crc<<1);}}return crc;
}void AHT20_Read_CTdata(uint32_t *ct)
{volatile uint8_t Byte_1th=0;volatile uint8_t Byte_2th=0;volatile uint8_t Byte_3th=0;volatile uint8_t Byte_4th=0;volatile uint8_t Byte_5th=0;volatile uint8_t Byte_6th=0;uint32_t RetuData = 0;uint16_t cnt = 0;AHT20_SendAC();Delay_1ms(80); cnt = 0;while(((AHT20_Read_Status()&0x80)==0x80)){SensorDelay_us(1508);if(cnt++>=100){break;}}I2C_Start();AHT20_WR_Byte(0x71);Receive_ACK();Byte_1th = AHT20_RD_Byte();Send_ACK();Byte_2th = AHT20_RD_Byte();Send_ACK();Byte_3th = AHT20_RD_Byte();Send_ACK();Byte_4th = AHT20_RD_Byte();Send_ACK();Byte_5th = AHT20_RD_Byte();Send_ACK();Byte_6th = AHT20_RD_Byte();Send_NOT_ACK();Stop_I2C();RetuData = (RetuData|Byte_2th)<<8;RetuData = (RetuData|Byte_3th)<<8;RetuData = (RetuData|Byte_4th);RetuData =RetuData >>4;ct[0] = RetuData;RetuData = 0;RetuData = (RetuData|Byte_4th)<<8;RetuData = (RetuData|Byte_5th)<<8;RetuData = (RetuData|Byte_6th);RetuData = RetuData&0xfffff;ct[1] =RetuData;}void AHT20_Read_CTdata_crc(uint32_t *ct)
{volatile uint8_t Byte_1th=0;volatile uint8_t Byte_2th=0;volatile uint8_t Byte_3th=0;volatile uint8_t Byte_4th=0;volatile uint8_t Byte_5th=0;volatile uint8_t Byte_6th=0;volatile uint8_t Byte_7th=0;uint32_t RetuData = 0;uint16_t cnt = 0;// uint8_t CRCDATA=0;uint8_t CTDATA[6]={0};AHT20_SendAC();Delay_1ms(80);cnt = 0;while(((AHT20_Read_Status()&0x80)==0x80)){SensorDelay_us(1508);if(cnt++>=100){break;}}I2C_Start();AHT20_WR_Byte(0x71);Receive_ACK();CTDATA[0]=Byte_1th = AHT20_RD_Byte();Send_ACK();CTDATA[1]=Byte_2th = AHT20_RD_Byte();Send_ACK();CTDATA[2]=Byte_3th = AHT20_RD_Byte();Send_ACK();CTDATA[3]=Byte_4th = AHT20_RD_Byte();Send_ACK();CTDATA[4]=Byte_5th = AHT20_RD_Byte();Send_ACK();CTDATA[5]=Byte_6th = AHT20_RD_Byte();Send_ACK();Byte_7th = AHT20_RD_Byte();Send_NOT_ACK();Stop_I2C();if(Calc_CRC8(CTDATA,6)==Byte_7th){RetuData = (RetuData|Byte_2th)<<8;RetuData = (RetuData|Byte_3th)<<8;RetuData = (RetuData|Byte_4th);RetuData =RetuData >>4;ct[0] = RetuData;RetuData = 0;RetuData = (RetuData|Byte_4th)<<8;RetuData = (RetuData|Byte_5th)<<8;RetuData = (RetuData|Byte_6th);RetuData = RetuData&0xfffff;ct[1] =RetuData;}else{ct[0]=0x00;ct[1]=0x00;}
}void AHT20_Init(void)
{ Init_I2C_Sensor_Port();I2C_Start();AHT20_WR_Byte(0x70);Receive_ACK();AHT20_WR_Byte(0xa8);Receive_ACK();AHT20_WR_Byte(0x00);Receive_ACK();AHT20_WR_Byte(0x00);Receive_ACK();Stop_I2C();Delay_1ms(10);I2C_Start();AHT20_WR_Byte(0x70);Receive_ACK();AHT20_WR_Byte(0xbe);Receive_ACK();AHT20_WR_Byte(0x08);Receive_ACK();AHT20_WR_Byte(0x00);Receive_ACK();Stop_I2C();Delay_1ms(10);
}
void JH_Reset_REG(uint8_t addr)
{uint8_t Byte_first,Byte_second,Byte_third;I2C_Start();AHT20_WR_Byte(0x70);Receive_ACK();AHT20_WR_Byte(addr);Receive_ACK();AHT20_WR_Byte(0x00);Receive_ACK();AHT20_WR_Byte(0x00);Receive_ACK();Stop_I2C();Delay_1ms(5);I2C_Start();AHT20_WR_Byte(0x71);//Receive_ACK();Byte_first = AHT20_RD_Byte();Send_ACK();Byte_second = AHT20_RD_Byte();Send_ACK();Byte_third = AHT20_RD_Byte();Send_NOT_ACK();Stop_I2C();Delay_1ms(10);I2C_Start();AHT20_WR_Byte(0x70);Receive_ACK();AHT20_WR_Byte(0xB0|addr);Receive_ACK();AHT20_WR_Byte(Byte_second);Receive_ACK();AHT20_WR_Byte(Byte_third);Receive_ACK();Stop_I2C();Byte_second=0x00;Byte_third =0x00;
}void AHT20_Start_Init(void)
{JH_Reset_REG(0x1b);JH_Reset_REG(0x1c);JH_Reset_REG(0x1e);
}2、新建AHT20-21_DEMO_V1_3.h文件，代码如下
#ifndef _AHT20_DEMO_
#define _AHT20_DEMO_#include "main.h" void Delay_N10us(uint32_t t);
void SensorDelay_us(uint32_t t);
void Delay_4us(void);
void Delay_5us(void);
void Delay_1ms(uint32_t t);
void AHT20_Clock_Init(void);
void SDA_Pin_Output_High(void) ;
void SDA_Pin_Output_Low(void);
void SDA_Pin_IN_FLOATING(void);
void SCL_Pin_Output_High(void);
void SCL_Pin_Output_Low(void);
void Init_I2C_Sensor_Port(void);
void I2C_Start(void);
void AHT20_WR_Byte(uint8_t Byte);
uint8_t AHT20_RD_Byte(void);
uint8_t Receive_ACK(void);
void Send_ACK(void) ;
void Send_NOT_ACK(void);
void Stop_I2C(void);
uint8_t AHT20_Read_Status(void);
uint8_t AHT20_Read_Cal_Enable(void);
void AHT20_SendAC(void);
uint8_t Calc_CRC8(uint8_t *message,uint8_t Num);
void AHT20_Read_CTdata(uint32_t *ct);
void AHT20_Read_CTdata_crc(uint32_t *ct);
void AHT20_Init(void);
void JH_Reset_REG(uint8_t addr);
void AHT20_Start_Init(void);#endif3、main.c文件
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "i2c.h"
#include "tim.h"
#include "usart.h"
#include "gpio.h"
#include "u8g2.h"
#include "stdio.h"
#include "AHT20-21_DEMO_V1_3.h"
//温
static const unsigned char wen[] =
{0x00,0x00,0xC4,0x1F,0x48,0x10,0x48,0x10,0xC1,0x1F,0x42,0x10,0x42,0x10,0xC8,0x1F,0x08,0x00,0xE4,0x3F,0x27,0x25,0x24,0x25,0x24,0x25,0x24,0x25,0xF4,0x7F,0x00,0x00};//湿
static const unsigned char shi[] ={0x00,0x00,0xE4,0x1F,0x28,0x10,0x28,0x10,0xE1,0x1F,0x22,0x10,0x22,0x10,0xE8,0x1F,0x88,0x04,0x84,0x04,0x97,0x24,0xA4,0x14,0xC4,0x0C,0x84,0x04,0xF4,0x7F,0x00,0x00};//度
static const unsigned char du[] ={0x80,0x00,0x00,0x01,0xFC,0x7F,0x44,0x04,0x44,0x04,0xFC,0x3F,0x44,0x04,0x44,0x04,0xC4,0x07,0x04,0x00,0xF4,0x0F,0x24,0x08,0x42,0x04,0x82,0x03,0x61,0x0C,0x1C,0x70};//待
static const unsigned char dai[]={0x10,0x02,0x10,0x02,0x08,0x02,0xC4,0x3F,0x12,0x02,0x10,0x02,0xE8,0x7F,0x0C,0x08,0x0A,0x08,0xE9,0x7F,0x08,0x08,0x48,0x08,0x88,0x08,0x88,0x08,0x08,0x0A,0x08,0x04};//检
static const unsigned char jian[]={0x08,0x02,0x08,0x02,0x08,0x05,0x08,0x05,0xBF,0x08,0x48,0x10,0xAC,0x6F,0x1C,0x00,0x2A,0x11,0x0A,0x12,0x49,0x12,0x88,0x0A,0x88,0x08,0x08,0x04,0xE8,0x7F,0x08,0x00};//测
static const unsigned char che[]={0x00,0x20,0xE4,0x23,0x28,0x22,0x28,0x2A,0xA1,0x2A,0xA2,0x2A,0xA2,0x2A,0xA8,0x2A,0xA8,0x2A,0xA4,0x2A,0xA7,0x2A,0x84,0x20,0x44,0x21,0x44,0x22,0x24,0x28,0x10,0x10};/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes *///write by luobitaihuangzhang/* 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 */
int fputc(int ch,FILE *f){HAL_UART_Transmit(&huart1,(uint8_t *)&ch,1,0xffff);return ch;
}
/* USER CODE END PFP *//* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 *//* USER CODE END 0 *//*** @brief The application entry point.* @retval int*/void oled_write(int temperature,int humidity){char t[5]; // 创建一个足够大的字符数组来存储转换后的数字char h[5];double t1=( double)temperature;double h1=(double)humidity;sprintf(t, "%.2f",t1/10 ); // 使用sprintf将int变量转换为字符串sprintf(h, "%.2f",h1/10);u8g2_t u8g2;u8g2Init(&u8g2); u8g2_ClearBuffer(&u8g2); u8g2_SetFont(&u8g2,u8g2_font_ncenB12_tf);//设置字体格式u8g2_DrawXBMP(&u8g2,16,0,16,16,wen);//（参数顺序依次是，结构体、x、y、字宽、字高、储存要显示的字点阵的数组）u8g2_DrawXBMP(&u8g2,32,0,16,16,du);u8g2_DrawStr(&u8g2,48,16,":");u8g2_DrawXBMP(&u8g2,16,32,16,16,shi);u8g2_DrawXBMP(&u8g2,32,32,16,16,du);u8g2_DrawStr(&u8g2,48,48,":");u8g2_DrawUTF8(&u8g2,55,16,t);u8g2_DrawUTF8(&u8g2,55,48,h);u8g2_SendBuffer(&u8g2);}void oled_write_init(){u8g2_t u8g2;u8g2Init(&u8g2); u8g2_ClearBuffer(&u8g2); u8g2_SetFont(&u8g2,u8g2_font_ncenB12_tf);//设置字体格式u8g2_DrawXBMP(&u8g2,16,0,16,16,wen);//（参数顺序依次是，结构体、x、y、字宽、字高、储存要显示的字点阵的数组）u8g2_DrawXBMP(&u8g2,32,0,16,16,du);u8g2_DrawStr(&u8g2,48,16,":");u8g2_DrawXBMP(&u8g2,16,32,16,16,shi);u8g2_DrawXBMP(&u8g2,32,32,16,16,du);u8g2_DrawStr(&u8g2,48,48,":");u8g2_DrawXBMP(&u8g2,58,0,16,16,dai);u8g2_DrawXBMP(&u8g2,74,0,16,16,jian);u8g2_DrawXBMP(&u8g2,90,0,16,16,che);u8g2_DrawXBMP(&u8g2,58,32,16,16,dai);u8g2_DrawXBMP(&u8g2,74,32,16,16,jian);u8g2_DrawXBMP(&u8g2,90,32,16,16,che);u8g2_SendBuffer(&u8g2);}
int main(void)
{/* USER CODE BEGIN 1 *//* USER CODE END 1 *//* MCU Configuration--------------------------------------------------------*//* Reset of all peripherals, Initializes the Flash interface and the Systick. */uint32_t CT_data[2]={0,0};volatile int c1,t1;Delay_1ms(500);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_I2C2_Init();MX_USART1_UART_Init();MX_I2C1_Init();MX_TIM1_Init();//初始化AHT20AHT20_Init();Delay_1ms(500);u8g2_t u8g2;u8g2Init(&u8g2);/* USER CODE BEGIN 2 *//* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */oled_write_init();while (1){/* USER CODE END WHILE */
/* USER CODE END WHILE */AHT20_Read_CTdata(CT_data); //不经过CRC校验，直接读取AHT20的温度和湿度数据 推荐每隔大于1S读一次//AHT20_Read_CTdata_crc(CT_data); //crc校验后，读取AHT20的温度和湿度数据 c1 = CT_data[0]*1000/1024/1024; //计算得到湿度值c1（放大了10倍）t1 = CT_data[1]*2000/1024/1024-500;//计算得到温度值t1（放大了10倍）printf("\r\n");HAL_Delay(1000);printf("温度:%d%d.%d",t1/100,(t1/10)%10,t1%10);printf("湿度:%d%d.%d",c1/100,(c1/10)%10,c1%10);printf("\r\n");printf("等待");printf("\r\n");HAL_Delay(1000);oled_write(t1,c1);/* 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_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();}
}/* 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****/4、演示
温湿度采集，OLED显示
参考链接
1、STM32F103基于I2C协议的AHT20温湿度传感器的数据采集_dht20程序-CSDN博客
2、IIC原理超详细讲解---值得一看-CSDN博客
3、温湿度采集与OLED显示-CSDN博客
