BME280 Temperature Compensation Issue

[Theorem25]

Hi,

I'm using the BME280 for a project, and is having hard time converting the sensor's ADC temperature value into "human" readable temperature, the values always off. I'm not sure whether the issue is with the compensation equations or somewhere else.  I'm able to write and read data back and forth between the  BME280 sensor and the microcontroller.

Below are sample pictures of the I2C communication

Get VersionRaw Temp and PressureRead Calibration Values

Compensation Equations to convert raw ADC value into human readable temperature. For instance, the UT value  at this moment in time  is 0x00086b2b. After that value went throught the equations, the t_fine_temp value is 0x00000594 or 1428 in decimal which is 14.28 degree C which i think is incorrect. Unfortunately, i don't know what the correct value should be.

int32_t BME280_CalcT(int32_t UT) 
{
#if 1

	volatile sLWord t_fine_temp = 0x0000;
	volatile sLWord t_fine_temp2= 0x0000;
	//int32_t t_fine_temp3;
	//int32_t t_fine_1;
	
#if 1
	t_fine_temp  = ((((UT >> 3) - ((sLWord)cal_param.dig_T1 << 1))) * ((sLWord)cal_param.dig_T2)) >> 11;
	t_fine_temp2 = (((((UT >> 4) - ((sLWord)cal_param.dig_T1)) * ((UT >> 4) - ((sLWord)cal_param.dig_T1))) >> 12) * ((sLWord)cal_param.dig_T3)) >> 14;
	t_fine_temp += t_fine_temp2;
	t_fine_temp = ((t_fine_temp * 5) + 128) >> 8;
#endif
	return t_fine_temp;
#endif
}

cal_param	0x00000116	0x000116`Ram	
	dig_T1	0x596f	0x000116`Ram	
	dig_T2	0x1067	0x000118`Ram	
	dig_T3	0x3200	0x00011a`Ram	

Can anyone show me where thing went wrong ?

Thank you very much

Vu

[Theorem25]

Hi All,

Thank you all very much for the help.

Sincerely,

Vu