SH20温湿度传感器利用I2C协议不再需要上拉电阻,直插直用,串口显示
单片机源程序如下:
- #include "SHT2x.h"
- #include "delay.h"
- #include "myiic.h"
- #include<stdio.h>
- SHT2x_data SHT20;
- u8 SHT2x_Init(void)
- {
- u8 err;
- IIC_Init();
- err = SHT2x_SoftReset();
- return err;
- }
- u8 SHT2x_SoftReset(void) //SHT20软件复位
- {
- u8 err=0;
- IIC_Start();
- IIC_Send_Byte(0x80);
- err = IIC_Wait_Ack();
- IIC_Send_Byte(0xFE);
- err = IIC_Wait_Ack();
- IIC_Stop();
- return err;
- }
- float SHT2x_GetTempPoll(void)
- {
- float TEMP;
- u8 ack, tmp1, tmp2;
- u16 ST;
- u16 i=0;
- IIC_Start(); //发送IIC开始信号
- IIC_Send_Byte(I2C_ADR_W); //IIC发送一个字节
- ack = IIC_Wait_Ack();
- IIC_Send_Byte(TRIG_TEMP_MEASUREMENT_POLL);
- ack = IIC_Wait_Ack();
- do {
- delay_ms(100);
- IIC_Start(); //发送IIC开始信号
- IIC_Send_Byte(I2C_ADR_R);
- i++;
- ack = IIC_Wait_Ack();
- if(i==1000)break;
- } while(ack!=0);
- tmp1 = IIC_Read_Byte(1);
- tmp2 = IIC_Read_Byte(1);
- IIC_Read_Byte(0);
- IIC_Stop();
-
- ST = (tmp1 << 8) | (tmp2 << 0);
-
- ST &= ~0x0003;
- TEMP = ((float)ST * 0.00268127) - 46.85;
- return (TEMP);
- }
- float SHT2x_GetHumiPoll(void)
- {
- float HUMI;
- u8 ack, tmp1, tmp2;
- u16 SRH;
- u16 i=0;
-
- IIC_Start(); //发送IIC开始信号
- IIC_Send_Byte(I2C_ADR_W); //IIC发送一个字节
- ack = IIC_Wait_Ack();
- IIC_Send_Byte(TRIG_HUMI_MEASUREMENT_POLL);
- ack = IIC_Wait_Ack();
- do {
- delay_ms(100);
- IIC_Start(); //发送IIC开始信号
- IIC_Send_Byte(I2C_ADR_R);
- i++;
- ack = IIC_Wait_Ack();
- if(i==100)break;
- } while(ack!=0);
-
- tmp1 = IIC_Read_Byte(1);
-
- tmp2 = IIC_Read_Byte(1);
- IIC_Read_Byte(0);
- IIC_Stop();
-
- SRH = (tmp1 << 8) | (tmp2 << 0);
- SRH &= ~0x0003;
- HUMI = ((float)SRH * 0.00190735) - 6;
- return (HUMI);
- }
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