iic copy

https://github.com/maomaojixiang/Circular_clock/blob/51f26fa5d602296c8937f06709566e54a3acf257/Circular_clock/CLOCK/sht30.c
https://github.com/search?q=sht30_data_process&type=code
https://www.cnblogs.com/zhangzeze/p/8834196.html
https://blog.csdn.net/qq_34885669/article/details/89240092
https://www.cnblogs.com/zhangzeze/p/8834196.html
https://bbs.huaweicloud.com/forum/forum/thread-34137-1-1.html 优质
https://blog.csdn.net/BearPi/article/details/104311539
https://www.extutorial.com/relative/2599341
https://blog.csdn.net/mculover666/article/details/100113106
https://blog.csdn.net/Mculover666/article/details/100132531
http://news.eeworld.com.cn/mcu/ic542648.html
https://www.mculover666.cn/posts/842429667/
https://zhuanlan.zhihu.com/p/80097994
https://www.shangmayuan.com/a/c51fb8c166224571ba06815e.html

static void delay_us(void)
{
	uint32_t i;
	
	for (i = 0; i < (45 * 5); i++)
	{
		__NOP();
	}
}

void delay_n_us(uint32_t nus)
{
	for(int i=0; i<nus; i++)
		delay_us();
}

static uint8_t I2C_Read_Byte(I2C_HandleTypeDef *hi2c,unsigned char ack)
{
	unsigned char i,receive=0;
	I2C_SDA_IN(hi2c); 
    for(i=0;i<8;i++ )
	{
        I2C_SCL_L(hi2c);
        delay_n_us(2);
		I2C_SCL_H(hi2c);
        receive<<=1;
        if(I2C_SDA_GET(hi2c))receive++;   
		delay_n_us(2);
    }					 
    if (!ack)
        I2C_Nack(hi2c);
    else
        I2C_Ack(hi2c); 
    return receive;
}


static void I2C_Start(I2C_HandleTypeDef *hi2c)
{	
	I2C_SDA_OUT(hi2c);    
	I2C_SCL_H(hi2c);
	I2C_SDA_H(hi2c);
	delay_n_us(4);
	
	I2C_SDA_L(hi2c);
	delay_n_us(4);
	
	I2C_SCL_L(hi2c);
	//delay_us();
}

static void I2C_Stop(I2C_HandleTypeDef *hi2c)
{
	I2C_SDA_OUT(hi2c);     
	I2C_SDA_L(hi2c);
	I2C_SCL_L(hi2c);
	delay_n_us(4);
	I2C_SDA_H(hi2c);
	I2C_SCL_H(hi2c);
	delay_n_us(4);
}

static void I2C_Ack(I2C_HandleTypeDef *hi2c)
{	
	I2C_SCL_L(hi2c);
	I2C_SDA_OUT(hi2c);
	I2C_SDA_L(hi2c);
	delay_n_us(2);
	I2C_SCL_H(hi2c);
	delay_n_us(2);
	I2C_SCL_L(hi2c);
	//I2C_SDA_IN(hi2c);
}

static void I2C_Nack(I2C_HandleTypeDef *hi2c)
{
	I2C_SCL_L(hi2c);
	I2C_SDA_OUT(hi2c);
	I2C_SDA_H(hi2c);
	delay_n_us(2);
	I2C_SCL_H(hi2c);
	delay_n_us(2);
	I2C_SCL_L(hi2c);
	//delay_us();
	//I2C_SDA_IN(hi2c);
}
static uint8_t I2C_Wait_Ack(I2C_HandleTypeDef *hi2c)
{
	uint8_t ucErrTime=0;
	I2C_SDA_IN(hi2c);      
	I2C_SDA_H(hi2c);delay_us();	   
	I2C_SCL_H(hi2c);delay_us();	 
	while(I2C_SDA_GET(hi2c))
	{
		ucErrTime++;
		if(ucErrTime>250)
		{
			I2C_Stop(hi2c);
			return 1;
		}
	}
	I2C_SCL_L(hi2c);	   
	return 0;  
} 
/*static uint8_t I2C_Wait_Ack(I2C_HandleTypeDef *hi2c)
{
	uint8_t ack;

	I2C_SDA_H(hi2c);
	delay_us();
	I2C_SDA_IN(hi2c);
	delay_us();
	I2C_SCL_H(hi2c);
	delay_us();
	ack = I2C_SDA_GET(hi2c);
	I2C_SCL_L(hi2c);
	delay_us();
	I2C_SDA_OUT(hi2c);

	return ack;
}

static void I2C_Write_Byte(I2C_HandleTypeDef *hi2c, uint8_t data)
{
	int i;
	I2C_SDA_OUT(hi2c);
	I2C_SCL_L(hi2c);
	for (i = 0; i < 8; i ++)
	{
		I2C_SDA(hi2c)=(data&0x80)>>7;
        data<<=1; 	  
		delay_us();   
		I2C_SCL_H(hi2c);
		delay_n_us(2);
		I2C_SCL_L(hi2c);
		delay_us();
	}
}*/
static void I2C_Write_Byte(I2C_HandleTypeDef *hi2c, uint8_t data)
{
	int i;
	I2C_SDA_OUT(hi2c);
	I2C_SCL_L(hi2c);
	for (i = 0; i < 8; i ++)
	{
		if (data & 0x80)
		{
			I2C_SDA_H(hi2c);
		}
		else
		{
			I2C_SDA_L(hi2c);
		}
		I2C_SCL_H(hi2c);
		delay_n_us(2);
		I2C_SCL_L(hi2c);
		delay_us();
		data <<= 1;
	}
}



/*数据处理*/
int sht30_data_process(void)
{
  uint8_t temporary[3];
  uint16_t data;
  uint8_t crc_result;
  sht30_read_temp_humi(&hi2c,data_process.sht30_data_buffer);
  temporary[0]=data_process.sht30_data_buffer[0];
  temporary[1]=data_process.sht30_data_buffer[1];
  temporary[2]=data_process.sht30_data_buffer[2];
  //crc校验
  crc_result=sht30_crc8_check(temporary,2,temporary[2]);
  if(crc_result==0)
  {
  data=((uint16_t)temporary[0] << 8) | temporary[1];
  //data_process.SHT30_temperature = (int)((175.0 * ((float)data) / 65535.0 - 45.0) *10.0);
	if (save_temperature_unit==0)
	{
	data_process.SHT30_temperature = (int)(175.0 * ((float)data) / 65535.0 - 45.0);
	save_temp = data_process.SHT30_temperature+save_temperature;
	}
	if (save_temperature_unit==1)
	{
	data_process.SHT30_temperature = (int)((175.0 * ((float)data) / 65535.0 - 45.0) * 1.8)+32.0;
	save_temp = data_process.SHT30_temperature+(save_temperature*1.8);
	}
	Write_temperature(21503,save_temp);
  //printf("温度 = %d save_temp = %d save_temperature = %d\n" , data_process.SHT30_temperature,save_temp,save_temperature); 
	}
	else
	{
	return 1;
	}
  temporary[0]=data_process.sht30_data_buffer[3];
  temporary[1]=data_process.sht30_data_buffer[4];
  temporary[2]=data_process.sht30_data_buffer[5];
  //crc校验
  crc_result=sht30_crc8_check(temporary,2,temporary[2]);
  	if(crc_result==0)
  {
  data=((uint16_t)temporary[0] << 8) | temporary[1];
  //data_process.SHT30_humidity = (int)((100.0 * (float)data / 65535.0) *10.0);
  data_process.SHT30_humidity = (int)(100.0 * (float)data / 65535.0);
  Write_temperature(21507,data_process.SHT30_humidity);
  //printf("湿度 = %d\n", data_process.SHT30_humidity); 
  return 0;
  }
  else
  {
  return 2;
  }
}





@卐词意不达 /*初始化SHT30*/
void SHT_Init(I2C_HandleTypeDef *hi2c)
{
   HAL_Delay(250); 
   	I2C_Start(hi2c);
   	I2C_Write_Byte(hi2c,0x88);
   	I2C_Wait_Ack(hi2c);
   	I2C_Write_Byte(hi2c,0x21);
   	I2C_Wait_Ack(hi2c);
   	I2C_Write_Byte(hi2c,0x30);
   	I2C_Wait_Ack(hi2c);
	I2C_Stop(hi2c);
   
   HAL_Delay(150); 
}
/*读SHT30数据*/
void sht30_read_temp_humi(I2C_HandleTypeDef *hi2c,uint8_t *p)
{
   I2C_Start(hi2c);
   I2C_Write_Byte(hi2c,0x88);
   I2C_Wait_Ack(hi2c);
   I2C_Write_Byte(hi2c,0xe0);
   I2C_Wait_Ack(hi2c);
   I2C_Write_Byte(hi2c,0x00);
   I2C_Wait_Ack(hi2c);
   I2C_Start(hi2c);
   I2C_Write_Byte(hi2c,0x89);
   I2C_Wait_Ack(hi2c);
   

   p[0] = I2C_Read_Byte(hi2c,1);
   p[1] = I2C_Read_Byte(hi2c,1);
   p[2] = I2C_Read_Byte(hi2c,1);
   p[3] = I2C_Read_Byte(hi2c,1);
   p[4] = I2C_Read_Byte(hi2c,1);
   p[5] = I2C_Read_Byte(hi2c,0);
   I2C_Stop(hi2c);
}
/*CRC算法*/
int crc8_compute(uint8_t *check_data, uint8_t num_of_data)
{
 uint8_t bit;        
 uint8_t crc = 0xFF; 
 uint8_t byteCtr;    

 for(byteCtr = 0; byteCtr < num_of_data; byteCtr++) {
     crc ^= (check_data[byteCtr]);
     for(bit = 8; bit > 0; --bit) {
         if(crc & 0x80) {
             crc = (crc << 1) ^ 0x31;
         }  else {
             crc = (crc << 1);
         }
     }
 }
 return crc;
}

int sht30_crc8_check(uint8_t *p,uint8_t num_of_data,uint8_t CrcData)
{
  uint8_t crc;
  crc = crc8_compute(p, num_of_data);// calculates 8-Bit checksum
 if(crc != CrcData) 
 {   
     return 1;           
 }
 return 0;
}
/*数据处理*/
int sht30_data_process(void)
{
  uint8_t temporary[3];
  uint16_t data;
  uint8_t crc_result;
  sht30_read_temp_humi(&hi2c,data_process.sht30_data_buffer);
  temporary[0]=data_process.sht30_data_buffer[0];
  temporary[1]=data_process.sht30_data_buffer[1];
  temporary[2]=data_process.sht30_data_buffer[2];
  //crc校验
  crc_result=sht30_crc8_check(temporary,2,temporary[2]);
  if(crc_result==0)
  {
  data=((uint16_t)temporary[0] << 8) | temporary[1];
  //data_process.SHT30_temperature = (int)((175.0 * ((float)data) / 65535.0 - 45.0) *10.0);
	if (