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Bosch Sensortec | BMP280 Data sheet

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Modifications reserved | Data subject to change without notice

Document number: BST-BMP280-DS001-26 Revision_1.26_102021

var1 = ((((adc_T>>3) – ((BMP280_S32_t)dig_T1<<1))) * ((BMP280_S32_t)dig_T2)) >> 11;

var2 = (((((adc_T>>4) – ((BMP280_S32_t)dig_T1)) * ((adc_T>>4) – ((BMP280_S32_t)dig_T1))) >> 12) *

((BMP280_S32_t)dig_T3)) >> 14;

t_fine = var1 + var2;

T = (t_fine * 5 + 128) >> 8;

return T;

}

// Returns pressure in Pa as unsigned 32 bit integer. Output value of “96386” equals 96386 Pa = 963.86 hPa

BMP280_U32_t bmp280_compensate_P_int32(BMP280_S32_t adc_P)

{

BMP280_S32_t var1, var2;

BMP280_U32_t p;

var1 = (((BMP280_S32_t)t_fine)>>1) – (BMP280_S32_t)64000;

var2 = (((var1>>2) * (var1>>2)) >> 11 ) * ((BMP280_S32_t)dig_P6);

var2 = var2 + ((var1*((BMP280_S32_t)dig_P5))<<1);

var2 = (var2>>2)+(((BMP280_S32_t)dig_P4)<<16);

var1 = (((dig_P3 * (((var1>>2) * (var1>>2)) >> 13 )) >> 3) + ((((BMP280_S32_t)dig_P2) * var1)>>1))>>18;

var1 =((((32768+var1))*((BMP280_S32_t)dig_P1))>>15);

if (var1 == 0)

{

return 0; // avoid exception caused by division by zero

}

p = (((BMP280_U32_t)(((BMP280_S32_t)1048576)-adc_P)-(var2>>12)))*3125;

if (p < 0x80000000)

{

p = (p << 1) / ((BMP280_U32_t)var1);

}

else

{

p = (p / (BMP280_U32_t)var1) * 2;

}

var1 = (((BMP280_S32_t)dig_P9) * ((BMP280_S32_t)(((p>>3) * (p>>3))>>13)))>>12;

var2 = (((BMP280_S32_t)(p>>2)) * ((BMP280_S32_t)dig_P8))>>13;

p = (BMP280_U32_t)((BMP280_S32_t)p + ((var1 + var2 + dig_P7) >> 4));

return p;

}

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