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2026-04-23 13:56:52 +08:00
#include "SHT20.h"
SHT20Var_t SHT20;
//---------- Defines -----------------------------------------------------------
// CRC 累加和校验常量
const uint32_t POLYNOMIAL = 0x131; //P(x)=x^8+x^5+x^4+1 = 100110001
/*
************************************************************
* 函数名称: SHT2x_CheckCrc
*
* 函数功能: 检查数据正确性
*
* 入口参数: data:读取到的数据
* nbrOfBytes:需要校验的数量
* checksum:读取到的校对比验值
*
* 返回参数: 校验结果
*
* 说明: 0-成功 1-失败
************************************************************
*/
uint8_t SHT2x_CheckCrc(uint8_t *data, uint8_t nbrOfBytes, uint8_t checksum)
{
uint8_t crc = 0;
uint8_t bit = 0;
uint8_t byteCtr = 0;
//calculates 8-Bit checksum with given polynomial
for(byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr) {
crc ^= (data[byteCtr]);
for ( bit = 8; bit > 0; --bit) {
if (crc & 0x80)
crc = (crc << 1) ^ POLYNOMIAL;
else
crc = (crc << 1);
}
}
if(crc != checksum)
return 1;
return 0;
}
void delay_us(int dlycnt)
{
for(int i = 0; i < dlycnt; i++) {
uint8_t temp = 10;
while(temp--);
}
}
#ifdef I2C_SOFTWARE
#define ACK 0 //应答信号
#define NACK 1 //非应答信号
#define SHT20_IN_SDA SHT20_I2C_SDA_Read() //读取SDA值
#define IIC_Delay() delay_us(10) //时钟延时
/*================================================================
[ Name ]void IO_I2CInit(void)
[Function]I2C初始化 空闲状态
[ Notes ]
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
void IO_I2CInit(void)
{
//
}
//
/*================================================================
[ Name ]SHT20_I2C_SDA_Read
[Function]读取SDA数据线上值
[ Notes ]
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
uint8_t SHT20_I2C_SDA_Read(void)
{
SHT20_SDA_IN();
if(SHT20_SDA_GET())
return 1;
else
return 0;
}
/*================================================================
[ Name ]I2CStart
[Function]开始
[ Notes ]
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
void I2CStart(void)
{
//uint8_t retval;
SHT20_SDA_OUT(); //设置成输出
//SHT20_SCL_OUT();
SHT20_I2C_SDA_HIGH(); //为SDA下降启动做准备
SHT20_I2C_SCL_HIGH(); //在SCL高电平时,SDA为下降沿时候总线启动
IIC_Delay();
SHT20_I2C_SDA_LOW(); //突变,总线启动
IIC_Delay();
SHT20_I2C_SCL_LOW();
IIC_Delay();
//SHT20_SDA_IN(); //设置成输入
// if(SHT20_IN_SDA)
// {
// retval= NACK;
// }
// else
// {
// retval= ACK;
// }
// retval=retval;
}
/*================================================================
[ Name ]I2CStop
[Function]结束
[ Notes ]
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
void I2CStop(void)
{
SHT20_SDA_OUT(); //设置成输出
SHT20_I2C_SDA_LOW(); //为SDA上升做准备
SHT20_I2C_SCL_LOW();
IIC_Delay();
SHT20_I2C_SCL_HIGH(); //在SCL高电平时,SDA为上升沿时候总线停止
IIC_Delay();
SHT20_I2C_SDA_HIGH(); //突变,总线停止
IIC_Delay();
}
/*================================================================
[ Name ]I2C_Write_Byte
[Function]写一个字节 返回ACK或NACK
[ Notes ]从高到低发
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
uint8_t I2C_Write_Byte(uint8_t Write_Byte) //Sendbyte
{
uint8_t i,retval=3;
SHT20_SDA_OUT(); //设置成输出
//SHT20_SCL_OUT() ;
for(i = 0;i < 8;i++) {
if(Write_Byte & 0x80)
SHT20_I2C_SDA_HIGH(); //判断发送位,先发送高位
else
SHT20_I2C_SDA_LOW();
//IIC_Delay();
SHT20_I2C_SCL_HIGH(); //为SCL下降做准备
IIC_Delay();
SHT20_I2C_SCL_LOW(); //突变,将数据位发送过去
IIC_Delay();
Write_Byte<<=1; //数据左移一位
} //字节发送完成,开始接收应答信号
IIC_Delay();
SHT20_I2C_SDA_HIGH(); //释放数据线
IIC_Delay();
SHT20_SDA_IN(); //设置成输入
//IIC_Delay();
SHT20_I2C_SCL_HIGH(); //为SCL下降做准备
IIC_Delay();
if(SHT20_IN_SDA)
retval= NACK;
else
retval= ACK;
SHT20_I2C_SCL_LOW();
IIC_Delay();
return retval;
}
//
/*================================================================
[ Name ]I2C_Read_Byte
[Function]读一个字节,入库参数用于控制应答状态 ACK或NAC
[ Notes ]从高到低
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
uint8_t I2C_Read_Byte(uint8_t AckValue)//receivebyte
{
uint8_t i;
uint8_t RXDATA=0;
// SHT20_SDA_OUT(); //设置成输出
// SHT20_I2C_SDA_HIGH(); //首先置数据线为高电平
// SHT20_I2C_SCL_LOW();
SHT20_SDA_IN(); //设置成输入
for(i = 0;i < 8;i++) {
SHT20_I2C_SCL_HIGH(); //突变
IIC_Delay();
RXDATA <<= 1; //读入数据,高位在前
if(SHT20_IN_SDA) RXDATA |= 0x01; //收到高电平
else RXDATA &= 0xfe;
IIC_Delay();
SHT20_I2C_SCL_LOW();
IIC_Delay();
} //数据接收完成
SHT20_SDA_OUT();
if(AckValue)
SHT20_I2C_SDA_HIGH();
else
SHT20_I2C_SDA_LOW();
IIC_Delay();
SHT20_I2C_SCL_HIGH();
IIC_Delay();
SHT20_I2C_SCL_LOW();
IIC_Delay();
return RXDATA; //返回读取到的数据
}
/*================================================================
[ Name ]SHT20_SoftReset
[Function]SHT20软件复位
[ Notes ]从高到低
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
void SHT20_Reset(void)
{
// IO_I2CInit(); //I2C initialize
I2CStart(); //start I2C
I2C_Write_Byte(SHT20_ADDRESS&0xfe); //I2C address + write
I2C_Write_Byte(0xfe); //soft reset
I2CStop(); //stop I2C
}
/*================================================================
[ Name ]SET_Resolution
[Function]写寄存器 设置分辨率
[ Notes ]从高到低
[ Author ]LZH
[ Data ]2016.06.22
================================================================*/
void SET_Resolution(void)
{
I2CStart(); //Start I2C
if(I2C_Write_Byte(SHT20_ADDRESS&0xfe) == ACK) { //I2C address + write + ACK
if(I2C_Write_Byte(0xe6) == ACK) { //写用户寄存器
if(I2C_Write_Byte(0x83) == ACK)
__NOP(); //设置分辨率 11bit RH% 测量时间:12ms(typ.) & 11bit T测量时间:9ms(typ.)
}
}
I2CStop(); //Stop I2C
}
/*================================================================
[ Name ]ReadSht20
[Function]非主机模式,读取温湿度值
[ Notes ]入口控制读取温度或湿度 复位需要15ms 温度转换最大需要85ms
[ Author ]LZH SHT20上电后等待20ms 再读取sht20
[ Data ]2016.06.22
================================================================*/
float SHT2x_MeasureHM(uint8_t whatdo)
{
float temp;
uint8_t MSB,LSB,checksum=0,checktemp[2];
float Humidity,Temperature;
uint32_t waitt= 1000;
//SET_Resolution(); //此处之前出过问题 所以屏蔽掉
I2CStart();
if(I2C_Write_Byte(SHT20_ADDRESS&0xfe)==ACK) { //I2C address + write + ACK
if(I2C_Write_Byte(whatdo)==ACK) { //Command
do{
delay_us(100); //加入超时
I2CStart();
if(--waitt==0)
break;
} while(I2C_Write_Byte(SHT20_ADDRESS|0x01) == NACK); //I2C address + read + NACK
if(waitt != 0) {
MSB = I2C_Read_Byte(ACK); //Data(MSB)
LSB = I2C_Read_Byte(ACK); //Data(LSB)
checksum=I2C_Read_Byte(NACK); //Checksum + NACK 累加和校验值
I2CStop(); //Stop I2C
checktemp[0]=MSB;
checktemp[1]=LSB;
if(SHT2x_CheckCrc(checktemp,2,checksum)) { //累加和校验成功
LSB &= 0xfc; //Data (LSB) 后两位清零
temp = MSB*256 + LSB; //十六进制转十进制
if (whatdo==((uint8_t)0xf5)) { //No Hold Master Mode,read humidity
/*-- calculate relative humidity [%RH] --*/
Humidity =(temp*125)/65536-6; //公式: RH%= -6 + 125 * SRH/2^16
return Humidity; //返回:humidity
}
else{ //No Hold Master Mode,read temperature
/*-- calculate temperature [℃] --*/
Temperature = (temp*175.72)/65536-46.85; //公式:T= -46.85 + 175.72 * ST/2^16
return Temperature; //返回:temperature
}
}
}
}
}
I2CStop(); //CT add
return 0;
}
//
/********************************************************
[ Name ]GetMiddleNum
[Function] 中值滤波
[ Notes ] 传入数据buf bArray, iFilterLen滤波数据长度
[ Author ] CSDN
[ Data ]2018.10.25
**********************************************************/
float GetMiddleNum(float * bArray, uint8_t iFilterLen)
{
uint8_t i,j;// 循环变量
float bTemp;
if(iFilterLen>100)
return 0;
// 用冒泡法对数组进行排序
for (j = 0; j < iFilterLen - 1; j ++) {
for (i = 0; i < iFilterLen - j - 1; i ++) {
if (bArray[i] > bArray[i + 1]) {
// 互换
bTemp = bArray[i];
bArray[i] = bArray[i + 1];
bArray[i + 1] = bTemp;
}
}
}
// 计算中值
if ((iFilterLen & 1) > 0) {
// 数组有奇数个元素,返回中间一个元素
bTemp = bArray[(iFilterLen -1) / 2];
}
else {
// 数组有偶数个元素,返回中间两个元素平均值
bTemp = (bArray[iFilterLen / 2-1] + bArray[iFilterLen / 2 ]) / 2;
}
return bTemp;
}
//
/********************************************************
[ Name ]ReadSht20_Medium
[Function] 获取中值
[ Notes ] 读取完后关闭上拉 设为低 (解决干扰问题)
[ Author ]
[ Data ]2018.10.25
**********************************************************/
float ReadSht20_Medium (void)
{
float arry3[3];
//SHT20_I2C_SET_PULL_UP(); //开启引脚上拉
for(uint8_t ui=0; ui<3; ui++) {
arry3[ui]= SHT2x_MeasureHM(SHT20_Measurement_T_HM);
delay_us(20);
//printf("sht origin %.2f \r\n",arry3[ui]);
}
float retv = GetMiddleNum(arry3, 3);
#ifdef I2C_SOFTWARE
//SHT20_I2C_SET_PULL_NO(); //关闭上拉
SHT20_I2C_LOW(); //读取完温度后拉低
#endif
return retv;
}
#else
/*
************************************************************
* 函数名称: SHT20_reset
*
* 函数功能: SHT20复位
*
* 入口参数: 无
*
* 返回参数: 无
*
* 说明:
************************************************************
*/
void SHT20_Reset(void)
{
uint8_t Data = SHT20_SOFT_RESET;
Sht20_Reg_Write(SHT20_ADDRESS, &Data, 1);
Sht20_Delay(15);
}
/*
************************************************************
* 函数名称: SHT20_read_user_reg
*
* 函数功能: SHT20读取用户寄存器
*
* 入口参数: 无
*
* 返回参数: 读取到的用户寄存器的值
*
* 说明:
************************************************************
*/
uint8_t SHT20_read_user_reg(void)
{
uint8_t val = 0;
uint8_t reg = SHT20_READ_REG;
Sht20_Read(SHT20_ADDRESS, &reg, &val, 1);
return val;
}
/*
************************************************************
* 函数名称: SHT2x_CalcTemperatureC
*
* 函数功能: 温度计算
*
* 入口参数: u16sT:读取到的温度原始数据
*
* 返回参数: 计算后的温度数据
*
* 说明:
************************************************************
*/
float SHT2x_CalcTemperatureC(uint16_t u16sT)
{
float temperatureC = 0; // 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;
}
/*
************************************************************
* 函数名称: SHT2x_CalcRH
*
* 函数功能: 湿度计算
*
* 入口参数: u16sRH:读取到的湿度原始数据
*
* 返回参数: 计算后的湿度数据
*
* 说明:
************************************************************
*/
float SHT2x_CalcRH(uint16_t u16sRH)
{
float humidityRH = 0; // 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
humidityRH = ((float)u16sRH * 0.00190735) - 6;
return humidityRH;
}
/*
************************************************************
* 函数名称: SHT2x_MeasureHM
*
* 函数功能: 测量温湿度
*
* 入口参数: cmd:测量温度还是湿度
*
* 返回参数: 测量结果
*
* 说明:
************************************************************
*/
float SHT2x_MeasureHM(uint8_t cmd)
{
uint8_t checksum = 0; //checksum
uint8_t data[3]; //data array for checksum verification
uint16_t tmp = 0;
float t = 0;
Sht20_Read(SHT20_ADDRESS, &cmd, data, 3);
checksum = data[2];
if(SHT2x_CheckCrc(data, 2, checksum) == 0) {
tmp = (data[0] << 8) + data[1];
if(cmd == SHT20_Measurement_T_NHM)
t = SHT2x_CalcTemperatureC(tmp);
else
t = SHT2x_CalcRH(tmp);
}
return t;
}
#endif
/*
************************************************************
* 函数名称: SHT20_GetValue
*
* 函数功能: 获取温湿度数据
*
* 入口参数: 无
*
* 返回参数: 无
*
* 说明: 温湿度结果保存在SHT20结构体里
************************************************************
*/
void SHT20_GetValue(float *Tempreture, float *Humidity)
{
if(Tempreture != NULL) {
*Tempreture = SHT20.Tempreture;
}
if(Humidity != NULL) {
*Humidity = SHT20.Humidity;
}
//SHT20_reset();
}
void SHT20Start(void)
{
memset(&SHT20, 0x00, sizeof(SHT20));
SHT20.Sht20Status = SHT20_INIT;
}
void SHT20LoopHandler(void)
{
uint8_t ret;
uint8_t rData[3];
switch(SHT20.Sht20Status) {
case SHT20_IDLE:
break;
case SHT20_INIT:
SHT20_Reset();
SHT20.Sht201mSDelayCnt = 200;
SHT20.Sht20Status = SHT20_READ_HUMI;
break;
case SHT20_READ_TEMPR:
if(SHT20.Sht201mSDelayCnt > 0)
break;
SHT20.Cmd = SHT20_Measurement_T_NHM;
ret = SHT20_StartMeas(SHT20_ADDRESS, &SHT20.Cmd);
if(ret == true) {
SHT20.Sht201mSDelayCnt = 90;
SHT20.Sht20Status = SHT20_READ_DATA;
}
else {
SHT20.Sht201mSDelayCnt = 1000;
SHT20.Sht20Status = SHT20_INIT;
}
break;
case SHT20_READ_HUMI:
if(SHT20.Sht201mSDelayCnt > 0)
break;
SHT20.Cmd = SHT20_Measurement_RH_NHM;
ret = SHT20_StartMeas(SHT20_ADDRESS, &SHT20.Cmd);
if(ret == true) {
SHT20.Sht201mSDelayCnt = 90;
SHT20.Sht20Status = SHT20_READ_DATA;
}
else {
SHT20.Sht201mSDelayCnt = 1000;
SHT20.Sht20Status = SHT20_INIT;
}
break;
case SHT20_READ_DATA:
if(SHT20.Sht201mSDelayCnt > 0)
break;
ret = SHT20_Readata(SHT20_ADDRESS, rData, 3);
if(ret == true) {
if(SHT2x_CheckCrc(rData, 2, rData[2]) == 0) {
uint16_t tmp = (rData[0] << 8) + rData[1];
if(SHT20.Cmd == SHT20_Measurement_T_NHM) {
SHT20.Tempreture = SHT2x_CalcTemperatureC(tmp);
SHT20.Sht20Status = SHT20_READ_HUMI;
}
else {
SHT20.Humidity = SHT2x_CalcRH(tmp);
SHT20.Sht20Status = SHT20_READ_TEMPR;
}
SHT20.Sht201mSDelayCnt = 5;
}
}
else {
SHT20.Sht201mSDelayCnt = 1000;
SHT20.Sht20Status = SHT20_INIT;
}
}
}
void SHT201mSRoutine(void)
{
if(SHT20.Sht201mSDelayCnt > 0)
SHT20.Sht201mSDelayCnt--;
}