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#define _C_SHT20Drv
#include "stm32l4xx_hal.h"
#include "SHT20Drv.h"
void IIC_Dealy_ms(int32_t nms);
#define DelayMicroSeconds(X) IIC_Dealy_ms(X)
u16 POLYNOMIAL = 0x131;
u8 SHT20Regiter;
u16 test;
u16 CNT_10ms_SHT20;
u16 Fg_Item_SHT20;
u16 Fg_SHT20Reset;
SHT20MeasureDef SHT20Measure;
void IIC_Dealy_ms(int32_t nms)
{
int32_t temp;
SysTick->LOAD = 8000*nms;
SysTick->VAL=0X00;
SysTick->CTRL=0X01;
do
{
temp=SysTick->CTRL;
}while((temp&0x01)&&(!(temp&(1<<16))));
SysTick->CTRL=0x00;
SysTick->VAL =0X00;
}
//==============================================================================
void I2c_StartCondition ()
//==============================================================================
{
/*
SDA=HIGH;
SCL=HIGH;
SDA=LOW;
DelayMicroSeconds(10); // hold time start condition (t_HD;STA)
SCL=LOW;
DelayMicroSeconds(10);
*/
SHT20_SDA(1);
SHT20_SCL(1);
SHT20_SDA(0);
DelayMicroSeconds(10);
SHT20_SCL(0);
DelayMicroSeconds(10);
}
//==============================================================================
void I2c_StopCondition ()
//==============================================================================
{
/*
SDA=LOW;
SCL=LOW;
SCL=HIGH;
DelayMicroSeconds(10); // set-up time stop condition (t_SU;STO)
SDA=HIGH;
DelayMicroSeconds(10);
*/
SHT20_SDA(0);
SHT20_SCL(0);
SHT20_SCL(1);
DelayMicroSeconds(10);
SHT20_SDA(1);
DelayMicroSeconds(10);
}
//==============================================================================
u8 I2c_WriteByte (u8 txByte)
//==============================================================================
{
u8 mask,error=0;
for (mask=0x80; mask>0; mask>>=1) //shift bit for masking (8 times)
{ if ((mask & txByte) == 0) SHT20_SDA(0);//SDA=LOW;//masking txByte, write bit to SDA-Line
else SHT20_SDA(1);//SDA=HIGH;
DelayMicroSeconds(1); //data set-up time (t_SU;DAT)
SHT20_SCL(1);//SCL=HIGH; //generate clock pulse on SCL
DelayMicroSeconds(5); //SCL high time (t_HIGH)
SHT20_SCL(0);//SCL=LOW;
DelayMicroSeconds(1); //data hold time(t_HD;DAT)
}
SHT20_SDA(1);//SDA=HIGH; //release SDA-line
SHT20_SCL(1);//SCL=HIGH; //clk #9 for ack
DelayMicroSeconds(1); //data set-up time (t_SU;DAT)
//if(SDA_CONF==HIGH) error=ACK_ERROR; //check ack from i2c slave
if(SHT20_SDA_Read) error= ACK_ERROR;
SHT20_SCL(0);//SCL=LOW;
DelayMicroSeconds(20); //wait time to see byte package on scope
return error; //return error code
}
//==============================================================================
u8 I2c_ReadByte (etI2cAck ack)
//==============================================================================
{
u8 mask,rxByte=0;
SHT20_SDA(1);//SDA=HIGH; //release SDA-line
for (mask=0x80; mask>0; mask>>=1) //shift bit for masking (8 times)
{ SHT20_SCL(1);//SCL=HIGH; //start clock on SCL-line
DelayMicroSeconds(1); //data set-up time (t_SU;DAT)
DelayMicroSeconds(3); //SCL high time (t_HIGH)
//if (SDA_CONF==1) rxByte=(rxByte | mask); //read bit
if (SHT20_SDA_Read) rxByte=(rxByte | mask);
SHT20_SCL(0);//SCL=LOW;
DelayMicroSeconds(1); //data hold time(t_HD;DAT)
}
SHT20_SDA(0);//SDA=ack; //send acknowledge if necessary
DelayMicroSeconds(1); //data set-up time (t_SU;DAT)
SHT20_SCL(1);//SCL=HIGH; //clk #9 for ack
DelayMicroSeconds(5); //SCL high time (t_HIGH)
SHT20_SCL(0);//SCL=LOW;
SHT20_SDA(1);//SDA=HIGH; //release SDA-line
DelayMicroSeconds(20); //wait time to see byte package on scope
return rxByte; //return error code
}
//==============================================================================
u8 SHT2x_CheckCrc(u8 data[], u8 nbrOfBytes, u8 checksum)
//==============================================================================
{
u8 crc = 0;
u8 byteCtr;
//calculates 8-Bit checksum with given polynomial
for (byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr)
{ crc ^= (data[byteCtr]);
for (u8 bit = 8; bit > 0; --bit)
{ if (crc & 0x80) crc = (crc << 1) ^ POLYNOMIAL;
else crc = (crc << 1);
}
}
if (crc != checksum) return CHECKSUM_ERROR;
else return 0;
}
//===========================================================================
u8 SHT2x_ReadUserRegister(u8 *pRegisterValue)
//===========================================================================
{
u8 checksum; //variable for checksum byte
u8 error=0; //variable for error code
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_W);
error |= I2c_WriteByte (USER_REG_R);
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_R);
*pRegisterValue = I2c_ReadByte(ACK);
checksum=I2c_ReadByte(NO_ACK);
error |= SHT2x_CheckCrc (pRegisterValue,1,checksum);
I2c_StopCondition();
return error;
}
//===========================================================================
u8 SHT2x_WriteUserRegister(u8 *pRegisterValue)
//===========================================================================
{
u8 error=0; //variable for error code
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_W);
error |= I2c_WriteByte (USER_REG_W);
error |= I2c_WriteByte (*pRegisterValue);
I2c_StopCondition();
return error;
}
//===========================================================================
u8 SHT2x_SoftReset()
//===========================================================================
{
u8 error=0; //error variable
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_W); // I2C Adr
error |= I2c_WriteByte (SOFT_RESET); // Command
I2c_StopCondition();
DelayMicroSeconds(15000); // wait till sensor has restarted
return error;
}
//==============================================================================
float SHT2x_CalcRH(u16 u16sRH)
//==============================================================================
{
float humidityRH; // variable for result
u16sRH &= ~0x0003; // clear bits [1..0] (status bits)
//-- calculate relative humidity [%RH] --
humidityRH = -6.0 + 125.0/65536 * (float)u16sRH; // RH= -6 + 125 * SRH/2^16
return humidityRH;
}
//==============================================================================
float SHT2x_CalcTemperatureC(u16 u16sT)
//==============================================================================
{
float temperatureC; // variable for result
u16sT &= ~0x0003; // clear bits [1..0] (status bits)
//-- calculate temperature --
temperatureC= -46.85 + 175.72/65536 *(float)u16sT; //T= -46.85 + 175.72 * ST/2^16
return temperatureC;
}
//==============================================================================
u8 SHT2x_GetSerialNumber(u8 u8SerialNumber[])
//==============================================================================
{
u8 error=0; //error variable
//Read from memory location 1
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_W); //I2C address
error |= I2c_WriteByte (0xFA); //Command for readout on-chip memory
error |= I2c_WriteByte (0x0F); //on-chip memory address
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_R); //I2C address
u8SerialNumber[5] = I2c_ReadByte(ACK); //Read SNB_3
I2c_ReadByte(ACK); //Read CRC SNB_3 (CRC is not analyzed)
u8SerialNumber[4] = I2c_ReadByte(ACK); //Read SNB_2
I2c_ReadByte(ACK); //Read CRC SNB_2 (CRC is not analyzed)
u8SerialNumber[3] = I2c_ReadByte(ACK); //Read SNB_1
I2c_ReadByte(ACK); //Read CRC SNB_1 (CRC is not analyzed)
u8SerialNumber[2] = I2c_ReadByte(ACK); //Read SNB_0
I2c_ReadByte(NO_ACK); //Read CRC SNB_0 (CRC is not analyzed)
I2c_StopCondition();
//Read from memory location 2
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_W); //I2C address
error |= I2c_WriteByte (0xFC); //Command for readout on-chip memory
error |= I2c_WriteByte (0xC9); //on-chip memory address
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_R); //I2C address
u8SerialNumber[1] = I2c_ReadByte(ACK); //Read SNC_1
u8SerialNumber[0] = I2c_ReadByte(ACK); //Read SNC_0
I2c_ReadByte(ACK); //Read CRC SNC0/1 (CRC is not analyzed)
u8SerialNumber[7] = I2c_ReadByte(ACK); //Read SNA_1
u8SerialNumber[6] = I2c_ReadByte(ACK); //Read SNA_0
I2c_ReadByte(NO_ACK); //Read CRC SNA0/1 (CRC is not analyzed)
I2c_StopCondition();
return error;
}
u8 SetSHT20Itme(etSHT2xMeasureType eSHT2xMeasureType)
{
u8 error=0;
I2c_StartCondition();
error |= I2c_WriteByte (I2C_ADR_W); // I2C Adr
switch(eSHT2xMeasureType)
{
case HUMIDITY: error |= I2c_WriteByte (TRIG_RH_MEASUREMENT_POLL); break;
case TEMP : error |= I2c_WriteByte (TRIG_T_MEASUREMENT_POLL); break;
}
return error;
}
void SHT20Init(void)
{
//SHT2x_ReadUserRegister(&SHT20Regiter);
SetSHT20Itme(HUMIDITY);
CNT_10ms_SHT20 = 0;
Fg_Item_SHT20 = 0;
Fg_SHT20Reset = 0;
}
void SHT20Process(void)
{
u8 data[2],checksum;
u16 Measure;
if(CNT_10ms_SHT20 >= SHT20ReadDelay_10ms || 1)
{
CNT_10ms_SHT20 = 0;
if(Fg_SHT20Reset == 1)
{
SHT20Init();
}
else
{
I2c_StartCondition();
if(I2c_WriteByte (I2C_ADR_R) == ACK_ERROR)
{
SHT2x_SoftReset();
Fg_SHT20Reset = 1;
}
else
{
data[0] = I2c_ReadByte(ACK);
data[1] = I2c_ReadByte(ACK);
Measure = data[0];
Measure<<=8;
Measure+=data[1];
checksum=I2c_ReadByte(NO_ACK);
I2c_StopCondition();
if(SHT2x_CheckCrc (data,2,checksum)==0)
{
if(Measure&0x0002)
{//濕度
SHT20Measure.HUMI = SHT2x_CalcRH(Measure);
}
else
{//溫度
SHT20Measure.TEMP = SHT2x_CalcTemperatureC(Measure);
}
}
Fg_Item_SHT20++;
if(Fg_Item_SHT20 ==1 )
{
SetSHT20Itme(TEMP);
}
else
{
Fg_Item_SHT20 = 0;
SetSHT20Itme(HUMIDITY);
}
}
}
}
}
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