【STM32C031试用】OLED+helloworld (stmicroelectronics.cn) 在这篇文章的基础上增加sht20的温度传感器采集程序。 1、在Src目录下新增sht20.c以及sht20.h： 2、sht20.c代码如下：

#include "sht20.h"
#include "main.h"
#include <stdio.h>

unsigned char SHT20_SoftReset(void)
{
    uint8_t buffer =SHT20_SOFT_RESET;
    if(HAL_OK==HAL_I2C_Master_Transmit(&hi2c1, SHT20_Write_Add, &buffer, 1, 1000))
    {
        printf("成功\r\n");
        return 0;
    }
    else
    {       
        printf("失败\r\n");
        return 1;
    }
}

unsigned char SHT20_Read_Reg(void)
{
    uint8_t buffer =SHT20_READ_REG;
    if(HAL_OK==HAL_I2C_Master_Transmit(&hi2c1, SHT20_Write_Add, &buffer, 1, 1000))
    {
        if(HAL_OK==HAL_I2C_Master_Receive(&hi2c1, SHT20_Write_Add, &buffer, 1, 1000))
            {
                return buffer;
            }
            else
                {       
                    return 1;
                }
    }
    else
    {       
        return 1;
    }

}
unsigned char SHT20_Config(void)//采集温度为14位，采集湿度为12位
{
    uint8_t val;
    val =   (SHT20_Read_Reg()&0x7E)|0x00;
    if(HAL_OK==HAL_I2C_Mem_Write(&hi2c1, (uint16_t)SHT20_Write_Add, (uint16_t)SHT20_WRITE_REG, (uint16_t)I2C_MEMADD_SIZE_8BIT, &val, 1, 1000))
    {
        return 0;
    }
    else
    {
        return 1;
    }
}


void SHT20_Init()
{
    if(SHT20_SoftReset())
    {
        printf("SHT20 复位失败\r\n");
    }
    else
    {
        printf("SHT20 复位成功\r\n");
    }
    HAL_Delay(100);
    if(SHT20_Config())
    {
        printf("初始化失败\r\n");
    }
    else
    {
        printf("初始化成功\r\n");
    }
}

float SHT20_GetTemperature(void)
{
    uint8_t val[3];
    if(HAL_OK==HAL_I2C_Mem_Read(&hi2c1, (uint16_t)SHT20_Write_Add, (uint16_t)SHT20_Measurement_T_HM, (uint16_t)I2C_MEMADD_SIZE_8BIT, val, 3, 1000))
    {
        return (-46.85 + (175.72 * (((val[0]<<8)|(val[1]&0xFC))) / 65536.0));
    }
    else
    {
        printf("error\r\n");
    }
}

float SHT20_GetHumidity(void)
{
    uint8_t val[3];
    if(HAL_OK==HAL_I2C_Mem_Read(&hi2c1, (uint16_t)SHT20_Write_Add, (uint16_t)SHT20_Measurement_RH_HM, (uint16_t)I2C_MEMADD_SIZE_8BIT, val, 3, 1000))
    {
        return -6+125*(((val[0]<<8)|(val[1]&0xF0))/65536.0);
    }
    else
    {
        printf("error\r\n");
    }
}

sht20.h代码如下：

#ifndef __SHT20_H
#define __SHT20_H

#include "main.h"

/*SHT20 设备操作相关宏定义，详见手册*/
#define SHT20_ADDRESS  0X40
#define SHT20_Write_Add 0x80   //STM32 hal库 slave地址为读地址
#define SHT20_Read_Add 0x81
#define SHT20_Measurement_RH_HM  0XE5
#define SHT20_Measurement_T_HM  0XE3
#define SHT20_Measurement_RH_NHM  0XF5  //非主机模式地址
#define SHT20_Measurement_T_NHM  0XF3   //非主机模式地址
#define SHT20_READ_REG  0XE7
#define SHT20_WRITE_REG  0XE6
#define SHT20_SOFT_RESET  0XFE

extern I2C_HandleTypeDef hi2c1;
void SHT20_Init(void);
unsigned char SHT20_SoftReset(void);
unsigned char SHT20_Read_Reg(void);
float SHT20_GetTemperature(void);
float SHT20_GetHumidity(void);




#endif

3、sht20接线，sht20也是i2c接口，sda接到D15，scl接到D14。 4、实现效果如图：

【小结】这次把sht20的代码移植过来后，内存不够用了，后面减少了字库，取消掉了printf打印float才编译过。在以后的使用中要节约内存了。