STM32Cube-15 | 使用硬件I2C读写温湿度传感器（SHT30）

/* ADDR Pin Conect to VSS */

#define    SHT30_ADDR_WRITE    0x44<<1         //10001000
#define    SHT30_ADDR_READ     (0x44<<1)+1     //10001011

typedef enum
{
    /* 软件复位命令 */

    SOFT_RESET_CMD = 0x30A2,    
    /*
    单次测量模式
    命名格式：Repeatability_CS_CMD
    CS：Clock stretching
    */
    HIGH_ENABLED_CMD    = 0x2C06,
    MEDIUM_ENABLED_CMD  = 0x2C0D,
    LOW_ENABLED_CMD     = 0x2C10,
    HIGH_DISABLED_CMD   = 0x2400,
    MEDIUM_DISABLED_CMD = 0x240B,
    LOW_DISABLED_CMD    = 0x2416,

    /*
    周期测量模式
    命名格式：Repeatability_MPS_CMD
    MPS：measurement per second
    */
    HIGH_0_5_CMD   = 0x2032,
    MEDIUM_0_5_CMD = 0x2024,
    LOW_0_5_CMD    = 0x202F,
    HIGH_1_CMD     = 0x2130,
    MEDIUM_1_CMD   = 0x2126,
    LOW_1_CMD      = 0x212D,
    HIGH_2_CMD     = 0x2236,
    MEDIUM_2_CMD   = 0x2220,
    LOW_2_CMD      = 0x222B,
    HIGH_4_CMD     = 0x2334,
    MEDIUM_4_CMD   = 0x2322,
    LOW_4_CMD      = 0x2329,
    HIGH_10_CMD    = 0x2737,
    MEDIUM_10_CMD  = 0x2721,
    LOW_10_CMD     = 0x272A,
    /* 周期测量模式读取数据命令 */
    READOUT_FOR_PERIODIC_MODE = 0xE000,
} SHT30_CMD;

/**
 * @brief    向SHT30发送一条指令(16bit)
 * @param    cmd —— SHT30指令（在SHT30_MODE中枚举定义）
 * @retval    成功返回HAL_OK
*/
static uint8_t    SHT30_Send_Cmd(SHT30_CMD cmd)
{
    uint8_t cmd_buffer[2];
    cmd_buffer[0] = cmd >> 8;
    cmd_buffer[1] = cmd;
    return HAL_I2C_Master_Transmit(&hi2c1, SHT30_ADDR_WRITE, (uint8_t* cmd_buffer, 2, 0xFFFF);
}

/**
 * @brief    复位SHT30
 * @param    none
 * @retval    none
*/
void SHT30_reset(void)
{
    SHT30_Send_Cmd(SOFT_RESET_CMD);
    HAL_Delay(20);
}

/**
 * @brief    初始化SHT30
 * @param    none
 * @retval    成功返回HAL_OK
 * @note    周期测量模式
*/
uint8_t SHT30_Init(void)
{
    return SHT30_Send_Cmd(MEDIUM_2_CMD);
}

/**
 * @brief    从SHT30读取一次数据
 * @param    dat —— 存储读取数据的地址（6个字节数组）
 * @retval    成功 —— 返回HAL_OK
*/
uint8_t SHT30_Read_Dat(uint8_t* dat)
{
    SHT30_Send_Cmd(READOUT_FOR_PERIODIC_MODE);
    return HAL_I2C_Master_Receive(&hi2c1, SHT30_ADDR_READ, dat, 6, 0xFFFF);
}

#define CRC8_POLYNOMIAL 0x31

uint8_t CheckCrc8(uint8_t* const message, uint8_t initial_value)
{
    uint8_t  remainder;        //余数
    uint8_t  i = 0, j = 0;  //循环变量

    /* 初始化 */
    remainder = initial_value;

    for(j = 0; j < 2;j++)
    {
        remainder ^= message[j];

        /* 从最高位开始依次计算  */
        for (i = 0; i < 8; i++)
        {
            if (remainder & 0x80)
            {
                remainder = (remainder << 1)^CRC8_POLYNOMIAL;
            }
            else
            {
                remainder = (remainder << 1);
            }
        }
    }

    /* 返回计算的CRC码 */
    return remainder;
}

/**
 * @brief    将SHT30接收的6个字节数据进行CRC校验，并转换为温度值和湿度值
 * @param    dat  —— 存储接收数据的地址（6个字节数组）
 * @retval    校验成功  —— 返回0
 *             校验失败  —— 返回1，并设置温度值和湿度值为0
*/
uint8_t SHT30_Dat_To_Float(uint8_t* const dat, float* temperature, float* humidity)
{
    uint16_t recv_temperature = 0;
    uint16_t recv_humidity = 0;

    /* 校验温度数据和湿度数据是否接收正确 */
    if(CheckCrc8(dat, 0xFF) != dat[2] || CheckCrc8(&dat[3], 0xFF) != dat[5])
        return 1;

    /* 转换温度数据 */
    recv_temperature = ((uint16_t)dat[0]<<8)|dat[1];
    *temperature = -45 + 175*((float)recv_temperature/65535);

    /* 转换湿度数据 */
    recv_humidity = ((uint16_t)dat[3]<<8)|dat[4];
    *humidity = 100 * ((float)recv_humidity / 65535);

    return 0;
}

#include <stdio.h>
#include "sht30_i2c_drv.h"

int main(void)
{
    /* USER CODE BEGIN 1 */
    uint8_t recv_dat[6] = {0};
    float temperature = 0.0;
    float humidity = 0.0;
    /* USER CODE END 1 */

    HAL_Init();

    SystemClock_Config();

    MX_GPIO_Init();
    MX_I2C1_Init();
    MX_USART1_UART_Init();

    /* USER CODE BEGIN 2 */
    SHT30_Reset();
    if(SHT30_Init() == HAL_OK)
        printf("sht30 init ok.\n");
    else
        printf("sht30 init fail.\n");
  /* USER CODE END 2 */

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

    /* USER CODE BEGIN 3 */
        HAL_Delay(1000);
        if(SHT30_Read_Dat(recv_dat) == HAL_OK)
        {
            if(SHT30_Dat_To_Float(recv_dat, &temperature, &humidity)==0)
            {
                printf("temperature = %f, humidity = %f\n", temperature, humidity);
            }
            else
            {
                printf("crc check fail.\n");
            }
        }
        else
        {
            printf("read data from sht30 fail.\n");
        }
    }
  /* USER CODE END 3 */
}