WLE5CC_NODE_STS/STS/RC/sht3x.c

//-- Includes -----------------------------------------------------------------
#include "sht3x.h"
//-- Defines ------------------------------------------------------------------
// Generator polynomial for CRC
#define POLYNOMIAL  0x131 // P(x) = x^8 + x^5 + x^4 + 1 = 100110001

static uint8_t SHT3x_Send_Data(SHT3x_CMD cmd);
static uint8_t SHT3x_Readout_Data(uint8_t *receive_original_data);

static float SHT3X_CalcTemperature(uint16_t rawValue);
static float SHT3X_CalcHumidity(uint16_t rawValue);

SHT3x_ReadData SHT3x_Data = {0.0, 0.0};
extern I2C_HandleTypeDef hi2c2;
#define	I2Cx	hi2c2
/**
 * @function: static uint8_t SHT3x_Send_Data(SHT3x_CMD cmd)
 * @description: SHT3x发送数据
 * @param {SHT3x_CMD}cmd待发送的指令数据
 * @return {0}发送成功
 * @return {1}发送失败
 */
static uint8_t SHT3x_Send_Data(SHT3x_CMD cmd)
{
  uint8_t cmd_buf[2];
  cmd_buf[0] = cmd >> 8;
  cmd_buf[1] = cmd;
#if SHT3X_USING_HARDWARE_I2C
  if (HAL_I2C_IsDeviceReady(&I2Cx, SHT3X_ADDRESS, 100, 1000))
    return 1;
  if (HAL_I2C_Master_Transmit(&I2Cx, SHT3X_ADDRESS, cmd_buf, 2, HAL_MAX_DELAY))
    return 1;
  return 0;
#endif

}

/**
 * @function: uint8_t SHT3x_Soft_Reset(void)
 * @description: SHT3x软件复位
 * @param {*}
 * @return {0}发送成功
 * @return {1}发送失败
 */
uint8_t SHT3x_Soft_Reset(void)
{
  if (SHT3x_Send_Data(SOFT_RESET))
    return 1;
  SHT3x_Delay_ms(10);
  return 0;
}

/**
 * @function: uint8_t SHT3x_Init_Measurement_Mode(SHT3x_CMD Mode)
 * @description: SHT3x测量模式设置
 * @param {SHT3x_CMD} Mode
 * @return {0}发送成功
 * @return {1}发送失败
 */
uint8_t SHT3x_Init_Measurement_Mode(SHT3x_CMD Mode)
{
  if (SHT3x_Send_Data(Mode))
    return 1;
  return 0;
  SHT3x_Delay_ms(20);
}

/**
 * @function: static uint8_t SHT3x_Readout_Data(uint8_t *receive_original_data)
 * @description: 从SHT3x周期模式读取数据
 * @param {uint8_t} *receive_original_data读取的数据6byte
 * @return {0}发送成功
 * @return {1}发送失败
 */
static uint8_t SHT3x_Readout_Data(uint8_t *receive_original_data)
{
#if SHT3X_USING_HARDWARE_I2C
  if (HAL_I2C_IsDeviceReady(&I2Cx, SHT3X_ADDRESS, 100, 1000))
    return 2;
  SHT3x_Send_Data(FETCH_DATA_PERIODIC);
  SHT3x_Delay_ms(20);
  if (HAL_I2C_Master_Receive(&I2Cx, SHT3X_ADDRESS, receive_original_data, 6, HAL_MAX_DELAY))
    return 1;
  return 0;
#endif
}

/**
 * @function: uint8_t SHT3x_Get_TemperatureHumidity(void)
 * @description: SHT3x温湿度读取
 * @param {*}
 * @return {0}发送成功
 * @return {1}发送失败
 */
uint8_t SHT3x_Get_TemperatureHumidity(float *temperature, float *humidity)
{
  uint8_t raw_data[6];
  uint16_t raw_temperature = 0;
  uint16_t raw_humidity = 0;
  SHT3x_Readout_Data(raw_data);
  if (CRC8_Calculation(raw_data, 0xFF) != raw_data[2] ||
      CRC8_Calculation(&raw_data[3], 0xFF) != raw_data[5])
    return 1;
  // /*温度转换*/
  raw_temperature = ((uint16_t)raw_data[0] << 8) | raw_data[1];

  // Temperature = -49 + 315 * ((float)original_temperature / 65535);//华氏度°F
  //*temperature =  (int)(-45.0 + (float)175.0 * ((float)raw_temperature / 65535)); //摄氏度°C
  *temperature = SHT3X_CalcTemperature(raw_temperature);
  /*湿度转换*/
  raw_humidity = ((uint16_t)raw_data[3] << 8) | raw_data[4];
  //SHT3x_Data.SHT3x_Humidity = 100 * ((float)original_humidity / 65535);
  //*humidity = (int)(100.0 * ((float)raw_humidity / 65535));
  *humidity = SHT3X_CalcHumidity(raw_humidity);
  return 0;
}


//-----------------------------------------------------------------------------
static float SHT3X_CalcTemperature(uint16_t rawValue)
{
  // calculate temperature [<5B>C]
  // T = -45 + 175 * rawValue / (2^16-1)
  return (float)(175.0f * (float)rawValue / 65535.0f - 45.0f);
}

//-----------------------------------------------------------------------------
static float SHT3X_CalcHumidity(uint16_t rawValue)
{
  // calculate relative humidity [%RH]
  // RH = rawValue / (2^16-1) * 100
  return (float)(100.0f * (float)rawValue / 65535.0f);
}
/**
 * @function: uint8_t CRC8_Calculation(uint8_t *const message, uint8_t initial_value)
 * @description: CRC8的校验计算
 * @param {uint8_t} *const message带校验数据信息
 * @param {uint8_t} initial_value设定初值0xFF
 * @return {uint8_t}remainder计算的CRC码
 */
uint8_t CRC8_Calculation(uint8_t *const message, uint8_t initial_value)
{
  const uint8_t CRC8_POLYNOMIAL = 0x31;
  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;
}