static void MX_I2C2_Init(void)
{hi2c2.Instance = I2C2;hi2c2.Init.ClockSpeed = 100000;hi2c2.Init.DutyCycle = I2C_DUTYCYCLE_2;hi2c2.Init.OwnAddress1 = 0;hi2c2.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;hi2c2.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;hi2c2.Init.OwnAddress2 = 0;hi2c2.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;hi2c2.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;if (HAL_I2C_Init(&hi2c2) != HAL_OK){Error_Handler();}
}对GPIO的初始化配置：
void HAL_I2C_MspInit(I2C_HandleTypeDef* hi2c)
{GPIO_InitTypeDef GPIO_InitStruct;if(hi2c->Instance==I2C2){/**I2C2 GPIO 配置PB10     ------> I2C2_SCLPB11     ------> I2C2_SDA */GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);__HAL_RCC_I2C2_CLK_ENABLE();}
}

//读取测量数据
uint8_t SHT2x_MeasureHM(etSHT2xMeasureType eSHT2xMeasureType, nt16 *pMeasurand)
{uint8_t checksum;uint8_t data[2];uint8_t error=0;uint16_t i;I2c_StartCondition();error |= I2c_WriteByte (I2C_ADR_W);switch(eSHT2xMeasureType){case HUMIDITY:{error |= I2c_WriteByte (TRIG_RH_MEASUREMENT_HM);break;}case TEMP :{error |= I2c_WriteByte (TRIG_T_MEASUREMENT_HM);break;}default: assert(0);}I2c_StartCondition();error |= I2c_WriteByte (I2C_ADR_R);SCL=HIGH;for(i=0; i<1000; i++){ DelayMicroSeconds(1000);if (SCL_CONF==1) break;}if(SCL_CONF==0) error |= TIME_OUT_ERROR;pMeasurand->s16.u8H = data[0] = I2c_ReadByte(ACK);pMeasurand->s16.u8L = data[1] = I2c_ReadByte(ACK);checksum=I2c_ReadByte(NO_ACK);error |= SHT2x_CheckCrc (data,2,checksum);I2c_StopCondition();return error;
}//软件复位
uint8_t SHT2x_SoftReset()
{uint8_t error=0;I2c_StartCondition();error |= I2c_WriteByte (I2C_ADR_W);error |= I2c_WriteByte (SOFT_RESET);I2c_StopCondition();DelayMicroSeconds(15000);return error;
}//计算相对湿度
float SHT2x_CalcRH(uint16_t u16sRH)
{ft humidityRH;u16sRH &= ~0x0003;humidityRH = -6.0 + 125.0/65536 * (ft)u16sRH;return humidityRH;
}//计算温度
float SHT2x_CalcTemperatureC(uint16_t u16sT)
{ft temperatureC;u16sT &= ~0x0003;temperatureC= -46.85 + 175.72/65536 *(ft)u16sT;return temperatureC;
}