自己編寫的基于IAR環境下STM32F103單片機讀取BME280程序，沒有太多的寄存器操作

ID:747769 · 發表于 2020-7-16 09:45

自己編寫的基于IAR環境下STM32F103單片機讀取BME280程序，沒有太多的寄存器操作，簡單易懂，可以直接調用，上電后只要對IO口初始化，調用函數Bme_ReadDigValue()讀取校準寄存器參數并保存，再調用函數Bme_Init()初始化之后就可以用函數Bme_ReadStatus()讀取傳感器狀態判斷是否讀取數據了，也可不判斷傳感器狀態直接讀取數據，讀取數據直接調用函數ReadBme280()。

單片機源程序：

void ReadBme280()
{
u32 value_ad;
double var1;
double var2;
double var3;
double var4;
double var5;
double var6;
double pressure;
double pressure_min = 30000.0;
double pressure_max = 110000.0;
double humidity;
double humidity_min = 0.0;
double humidity_max = 100.0;
u8 temp[10];
///////////////// temp /////////////////
Bme_Read(Adds_RegValueTempStart,temp,3);
value_ad = ( ((temp[0]<<16)+(temp[1]<<8)+(temp[2]&0xf0))>>4 );
var1 = ( ((value_ad>>3)-(Bme280.dig_T1<<1))*Bme280.dig_T2 )>>11;
var2 = (((((value_ad>>4)-Bme280.dig_T1)*((value_ad>>4)-Bme280.dig_T1))>>12)*Bme280.dig_T3)>>14;
Bme280.t_fine = var1+var2;
Bme280.temp = ( (Bme280.t_fine*5+128)>>8);
Bme280.temp = Bme280.temp;
///////////////// press /////////////////
Bme_Read(Adds_RegValuePressStart,temp,3);
value_ad = ( ((temp[0]<<16)+(temp[1]<<8)+(temp[2]&0xf0))>>4 );
var1 = ((double)Bme280.t_fine / 2.0) - 64000.0;
var2 = var1 * var1 * ((double)Bme280.dig_P6) / 32768.0;
var2 = var2 + var1 * ((double)Bme280.dig_P5) * 2.0;
var2 = (var2 / 4.0) + (((double)Bme280.dig_P4) * 65536.0);
var3 = ((double)Bme280.dig_P3) * var1 * var1 / 524288.0;
var1 = (var3 + ((double)Bme280.dig_P2) * var1) / 524288.0;
var1 = (1.0 + var1 / 32768.0) * ((double)Bme280.dig_P1);
if (var1 > (0.0))
{
pressure = 1048576.0 - (double)value_ad;
pressure = (pressure - (var2 / 4096.0)) * 6250.0 / var1;
var1 = ((double)Bme280.dig_P9) * pressure * pressure / 2147483648.0;
var2 = pressure * ((double)Bme280.dig_P8) / 32768.0;
pressure = pressure + (var1 + var2 + ((double)Bme280.dig_P7)) / 16.0;
if (pressure < pressure_min)
{
pressure = pressure_min;
}
else if (pressure > pressure_max)
{
pressure = pressure_max;
}
}
else
{
pressure = pressure_min;
}
Bme280.press = pressure;
Bme280.press = Bme280.press*100;
///////////////// humidity /////////////////
Bme_Read(Adds_RegValueHumStart,temp,2);
value_ad = ( (temp[0]<<8)+temp[1] );
var1 = ((double)Bme280.t_fine) - 76800.0;
var2 = (((double)Bme280.dig_H4) * 64.0 + (((double)Bme280.dig_H5) / 16384.0) * var1);
var3 = value_ad - var2;
var4 = ((double)Bme280.dig_H2) / 65536.0;
var5 = (1.0 + (((double)Bme280.dig_H3) / 67108864.0) * var1);
var6 = 1.0 + (((double)Bme280.dig_H6) / 67108864.0) * var1 * var5;
var6 = var3 * var4 * (var5 * var6);
humidity = var6 * (1.0 - ((double)Bme280.dig_H1) * var6 / 524288.0);
if (humidity > humidity_max)
{
humidity = humidity_max;
}
else if (humidity < humidity_min)
{
humidity = humidity_min;
}
Bme280.hum = humidity*100;// 結果包含2位小數
}
void BmeReset()
{
u8 temp[50];
temp[0] = CMD_Bme280Reset;
Bme_Write(Reg_Bme280Reset,temp,1);
}