616 lines
14 KiB
C++
616 lines
14 KiB
C++
#include "SHT20.h"
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SHT20Var_t SHT20;
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//---------- Defines -----------------------------------------------------------
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// CRC 累加和校验常量
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const uint32_t POLYNOMIAL = 0x131; //P(x)=x^8+x^5+x^4+1 = 100110001
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/*
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************************************************************
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* 函数名称： SHT2x_CheckCrc
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*
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* 函数功能： 检查数据正确性
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*
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* 入口参数： data：读取到的数据
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* nbrOfBytes：需要校验的数量
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* checksum：读取到的校对比验值
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*
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* 返回参数： 校验结果
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*
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* 说明： 0-成功 1-失败
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************************************************************
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*/
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uint8_t SHT2x_CheckCrc(uint8_t *data, uint8_t nbrOfBytes, uint8_t checksum)
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{
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uint8_t crc = 0;
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uint8_t bit = 0;
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uint8_t byteCtr = 0;
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//calculates 8-Bit checksum with given polynomial
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for(byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr) {
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crc ^= (data[byteCtr]);
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for ( bit = 8; bit > 0; --bit) {
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if (crc & 0x80)
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crc = (crc << 1) ^ POLYNOMIAL;
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else
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crc = (crc << 1);
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}
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}
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if(crc != checksum)
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return 1;
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return 0;
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}
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void delay_us(int dlycnt)
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{
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for(int i = 0; i < dlycnt; i++) {
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uint8_t temp = 10;
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while(temp--);
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}
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}
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#ifdef I2C_SOFTWARE
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#define ACK 0 //应答信号
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#define NACK 1 //非应答信号
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#define SHT20_IN_SDA SHT20_I2C_SDA_Read() //读取SDA值
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#define IIC_Delay() delay_us(10) //时钟延时
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/*================================================================
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[ Name ]void IO_I2CInit(void)
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[Function]I2C初始化 空闲状态
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[ Notes ]
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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void IO_I2CInit(void)
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{
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//
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}
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//
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/*================================================================
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[ Name ]SHT20_I2C_SDA_Read
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[Function]读取SDA数据线上值
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[ Notes ]
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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uint8_t SHT20_I2C_SDA_Read(void)
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{
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SHT20_SDA_IN();
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if(SHT20_SDA_GET())
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return 1;
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else
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return 0;
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}
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/*================================================================
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[ Name ]I2CStart
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[Function]开始
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[ Notes ]
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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void I2CStart(void)
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{
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//uint8_t retval;
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SHT20_SDA_OUT(); //设置成输出
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//SHT20_SCL_OUT();
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SHT20_I2C_SDA_HIGH(); //为SDA下降启动做准备
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SHT20_I2C_SCL_HIGH(); //在SCL高电平时，SDA为下降沿时候总线启动
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IIC_Delay();
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SHT20_I2C_SDA_LOW(); //突变，总线启动
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IIC_Delay();
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SHT20_I2C_SCL_LOW();
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IIC_Delay();
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//SHT20_SDA_IN(); //设置成输入
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// if(SHT20_IN_SDA)
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// {
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// retval= NACK;
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// }
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// else
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// {
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// retval= ACK;
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// }
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// retval=retval;
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}
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/*================================================================
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[ Name ]I2CStop
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[Function]结束
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[ Notes ]
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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void I2CStop(void)
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{
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SHT20_SDA_OUT(); //设置成输出
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SHT20_I2C_SDA_LOW(); //为SDA上升做准备
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SHT20_I2C_SCL_LOW();
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IIC_Delay();
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SHT20_I2C_SCL_HIGH(); //在SCL高电平时，SDA为上升沿时候总线停止
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IIC_Delay();
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SHT20_I2C_SDA_HIGH(); //突变，总线停止
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IIC_Delay();
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}
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/*================================================================
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[ Name ]I2C_Write_Byte
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[Function]写一个字节 返回ACK或NACK
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[ Notes ]从高到低发
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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uint8_t I2C_Write_Byte(uint8_t Write_Byte) //Sendbyte
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{
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uint8_t i,retval=3;
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SHT20_SDA_OUT(); //设置成输出
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//SHT20_SCL_OUT() ;
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for(i = 0;i < 8;i++) {
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if(Write_Byte & 0x80)
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SHT20_I2C_SDA_HIGH(); //判断发送位，先发送高位
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else
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SHT20_I2C_SDA_LOW();
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//IIC_Delay();
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SHT20_I2C_SCL_HIGH(); //为SCL下降做准备
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IIC_Delay();
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SHT20_I2C_SCL_LOW(); //突变，将数据位发送过去
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IIC_Delay();
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Write_Byte<<=1; //数据左移一位
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} //字节发送完成，开始接收应答信号
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IIC_Delay();
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SHT20_I2C_SDA_HIGH(); //释放数据线
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IIC_Delay();
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SHT20_SDA_IN(); //设置成输入
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//IIC_Delay();
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SHT20_I2C_SCL_HIGH(); //为SCL下降做准备
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IIC_Delay();
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if(SHT20_IN_SDA)
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retval= NACK;
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else
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retval= ACK;
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SHT20_I2C_SCL_LOW();
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IIC_Delay();
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return retval;
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}
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//
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/*================================================================
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[ Name ]I2C_Read_Byte
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[Function]读一个字节，入库参数用于控制应答状态 ACK或NAC
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[ Notes ]从高到低
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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uint8_t I2C_Read_Byte(uint8_t AckValue)//receivebyte
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{
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uint8_t i;
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uint8_t RXDATA=0;
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// SHT20_SDA_OUT(); //设置成输出
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// SHT20_I2C_SDA_HIGH(); //首先置数据线为高电平
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// SHT20_I2C_SCL_LOW();
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SHT20_SDA_IN(); //设置成输入
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for(i = 0;i < 8;i++) {
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SHT20_I2C_SCL_HIGH(); //突变
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IIC_Delay();
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RXDATA <<= 1; //读入数据，高位在前
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if(SHT20_IN_SDA) RXDATA |= 0x01; //收到高电平
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else RXDATA &= 0xfe;
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IIC_Delay();
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SHT20_I2C_SCL_LOW();
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IIC_Delay();
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} //数据接收完成
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SHT20_SDA_OUT();
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if(AckValue)
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SHT20_I2C_SDA_HIGH();
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else
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SHT20_I2C_SDA_LOW();
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IIC_Delay();
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SHT20_I2C_SCL_HIGH();
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IIC_Delay();
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SHT20_I2C_SCL_LOW();
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IIC_Delay();
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return RXDATA; //返回读取到的数据
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}
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/*================================================================
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[ Name ]SHT20_SoftReset
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[Function]SHT20软件复位
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[ Notes ]从高到低
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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void SHT20_Reset(void)
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{
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// IO_I2CInit(); //I2C initialize
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I2CStart(); //start I2C
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I2C_Write_Byte(SHT20_ADDRESS&0xfe); //I2C address + write
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I2C_Write_Byte(0xfe); //soft reset
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I2CStop(); //stop I2C
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}
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/*================================================================
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[ Name ]SET_Resolution
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[Function]写寄存器 设置分辨率
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[ Notes ]从高到低
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[ Author ]LZH
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[ Data ]2016.06.22
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================================================================*/
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void SET_Resolution(void)
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{
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I2CStart(); //Start I2C
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if(I2C_Write_Byte(SHT20_ADDRESS&0xfe) == ACK) { //I2C address + write + ACK
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if(I2C_Write_Byte(0xe6) == ACK) { //写用户寄存器
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if(I2C_Write_Byte(0x83) == ACK)
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__NOP(); //设置分辨率 11bit RH% 测量时间:12ms(typ.) & 11bit T测量时间:9ms(typ.)
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}
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}
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I2CStop(); //Stop I2C
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}
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/*================================================================
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[ Name ]ReadSht20
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[Function]非主机模式，读取温湿度值
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[ 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
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[ Author ]LZH SHT20上电后等待20ms 再读取sht20
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[ Data ]2016.06.22
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================================================================*/
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float SHT2x_MeasureHM(uint8_t whatdo)
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{
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float temp;
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uint8_t MSB,LSB,checksum=0,checktemp[2];
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float Humidity,Temperature;
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uint32_t waitt= 1000;
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//SET_Resolution(); //此处之前出过问题 所以屏蔽掉
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I2CStart();
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if(I2C_Write_Byte(SHT20_ADDRESS&0xfe)==ACK) { //I2C address + write + ACK
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if(I2C_Write_Byte(whatdo)==ACK) { //Command
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do{
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delay_us(100); //加入超时
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I2CStart();
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if(--waitt==0)
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break;
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} while(I2C_Write_Byte(SHT20_ADDRESS|0x01) == NACK); //I2C address + read + NACK
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if(waitt != 0) {
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MSB = I2C_Read_Byte(ACK); //Data(MSB)
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LSB = I2C_Read_Byte(ACK); //Data(LSB)
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checksum=I2C_Read_Byte(NACK); //Checksum + NACK 累加和校验值
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I2CStop(); //Stop I2C
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checktemp[0]=MSB;
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checktemp[1]=LSB;
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if(SHT2x_CheckCrc(checktemp,2,checksum)) { //累加和校验成功
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LSB &= 0xfc; //Data (LSB) 后两位清零
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temp = MSB*256 + LSB; //十六进制转十进制
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if (whatdo==((uint8_t)0xf5)) { //No Hold Master Mode,read humidity
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/*-- calculate relative humidity [%RH] --*/
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Humidity =(temp*125)/65536-6; //公式: RH%= -6 + 125 * SRH/2^16
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return Humidity; //返回:humidity
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}
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else{ //No Hold Master Mode,read temperature
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/*-- calculate temperature [℃] --*/
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Temperature = (temp*175.72)/65536-46.85; //公式:T= -46.85 + 175.72 * ST/2^16
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return Temperature; //返回:temperature
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}
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}
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}
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}
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}
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I2CStop(); //CT add
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return 0;
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}
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//
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/********************************************************
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[ Name ]GetMiddleNum
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[Function] 中值滤波
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[ Notes ] 传入数据buf bArray, iFilterLen滤波数据长度
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[ Author ] CSDN
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[ Data ]2018.10.25
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**********************************************************/
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float GetMiddleNum(float * bArray, uint8_t iFilterLen)
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{
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uint8_t i,j;// 循环变量
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float bTemp;
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if(iFilterLen>100)
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return 0;
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// 用冒泡法对数组进行排序
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for (j = 0; j < iFilterLen - 1; j ++) {
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for (i = 0; i < iFilterLen - j - 1; i ++) {
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if (bArray[i] > bArray[i + 1]) {
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// 互换
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bTemp = bArray[i];
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bArray[i] = bArray[i + 1];
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bArray[i + 1] = bTemp;
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}
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}
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}
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// 计算中值
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if ((iFilterLen & 1) > 0) {
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// 数组有奇数个元素，返回中间一个元素
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bTemp = bArray[(iFilterLen -1) / 2];
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}
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else {
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// 数组有偶数个元素，返回中间两个元素平均值
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bTemp = (bArray[iFilterLen / 2-1] + bArray[iFilterLen / 2 ]) / 2;
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}
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return bTemp;
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}
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//
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/********************************************************
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[ Name ]ReadSht20_Medium
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[Function] 获取中值
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[ Notes ] 读取完后关闭上拉 设为低 (解决干扰问题)
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[ Author ]
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[ Data ]2018.10.25
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**********************************************************/
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float ReadSht20_Medium (void)
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{
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float arry3[3];
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//SHT20_I2C_SET_PULL_UP(); //开启引脚上拉
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for(uint8_t ui=0; ui<3; ui++) {
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arry3[ui]= SHT2x_MeasureHM(SHT20_Measurement_T_HM);
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delay_us(20);
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//printf("sht origin %.2f \r\n",arry3[ui]);
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}
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float retv = GetMiddleNum(arry3, 3);
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#ifdef I2C_SOFTWARE
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//SHT20_I2C_SET_PULL_NO(); //关闭上拉
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SHT20_I2C_LOW(); //读取完温度后拉低
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#endif
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return retv;
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}
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#else
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/*
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************************************************************
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* 函数名称： SHT20_reset
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*
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* 函数功能： SHT20复位
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*
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* 入口参数： 无
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*
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* 返回参数： 无
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*
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* 说明：
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************************************************************
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*/
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void SHT20_Reset(void)
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{
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uint8_t Data = SHT20_SOFT_RESET;
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Sht20_Reg_Write(SHT20_ADDRESS, &Data, 1);
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Sht20_Delay(15);
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}
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/*
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************************************************************
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* 函数名称： SHT20_read_user_reg
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*
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* 函数功能： SHT20读取用户寄存器
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*
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* 入口参数： 无
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*
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* 返回参数： 读取到的用户寄存器的值
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*
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* 说明：
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************************************************************
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*/
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uint8_t SHT20_read_user_reg(void)
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{
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uint8_t val = 0;
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uint8_t reg = SHT20_READ_REG;
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Sht20_Read(SHT20_ADDRESS, ®, &val, 1);
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return val;
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}
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/*
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************************************************************
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* 函数名称： SHT2x_CalcTemperatureC
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*
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* 函数功能： 温度计算
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*
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* 入口参数： u16sT：读取到的温度原始数据
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*
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* 返回参数： 计算后的温度数据
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*
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* 说明：
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************************************************************
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*/
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float SHT2x_CalcTemperatureC(uint16_t u16sT)
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{
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float temperatureC = 0; // variable for result
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u16sT &= ~0x0003; // clear bits [1..0] (status bits)
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//-- calculate temperature [℃] --
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temperatureC = -46.85 + 175.72 / 65536 * (float)u16sT; //T= -46.85 + 175.72 * ST/2^16
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return temperatureC;
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}
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/*
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************************************************************
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* 函数名称： SHT2x_CalcRH
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*
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* 函数功能： 湿度计算
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*
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* 入口参数： u16sRH：读取到的湿度原始数据
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*
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* 返回参数： 计算后的湿度数据
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*
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* 说明：
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************************************************************
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*/
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float SHT2x_CalcRH(uint16_t u16sRH)
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{
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float humidityRH = 0; // variable for result
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u16sRH &= ~0x0003; // clear bits [1..0] (status bits)
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//-- calculate relative humidity [%RH] --
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//humidityRH = -6.0 + 125.0/65536 * (float)u16sRH; // RH= -6 + 125 * SRH/2^16
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humidityRH = ((float)u16sRH * 0.00190735) - 6;
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return humidityRH;
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}
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/*
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************************************************************
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* 函数名称： SHT2x_MeasureHM
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*
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* 函数功能： 测量温湿度
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*
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* 入口参数： cmd：测量温度还是湿度
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*
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* 返回参数： 测量结果
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*
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* 说明：
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************************************************************
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*/
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float SHT2x_MeasureHM(uint8_t cmd)
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{
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uint8_t checksum = 0; //checksum
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uint8_t data[3]; //data array for checksum verification
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uint16_t tmp = 0;
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|
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--;
|
|
}
|
|
|