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bme280.c
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bme280.c
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#include "driver/bme280.h"
// sensor init
static uint8 _address = 0;
// calibration values
static uint16 dig_T1;
static sint16 dig_T2;
static sint16 dig_T3;
static uint16 dig_P1;
static sint16 dig_P2;
static sint16 dig_P3;
static sint16 dig_P4;
static sint16 dig_P5;
static sint16 dig_P6;
static sint16 dig_P7;
static sint16 dig_P8;
static sint16 dig_P9;
static uint8 dig_H1;
static sint16 dig_H2;
static uint8 dig_H3;
static sint16 dig_H4;
static sint16 dig_H5;
static sint8 dig_H6;
// global temp variable
static sint32 t_fine;
// typedefs to avoid renaming of datasheet types
typedef uint32 BME280_U32_t;
typedef sint32 BME280_S32_t;
typedef sint64 BME280_S64_t;
void BME280_init(uint8 address)
{
if (I2C_read_single(address, BME280_REG_ID) != BME280_ID) {
return;
}
_address = address;
I2C_write_single(_address, BME280_REG_CTRL_HUM,
BME280_OVERSAMPL_HUM_X01);
I2C_write_single(_address, BME280_REG_CTRL_MEAS,
BME280_MODE_NORMAL |
BME280_OVERSAMPL_TEM_X01 |
BME280_OVERSAMPL_PRS_X01);
I2C_write_single(_address, BME280_REG_CONFIG,
BME280_T_STANDBY_MS_1000);
dig_T1 = (uint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_T1_LSB, 16);
dig_T2 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_T2_LSB, 16);
dig_T3 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_T3_LSB, 16);
dig_P1 = (uint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P1_LSB, 16);
dig_P2 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P2_LSB, 16);
dig_P3 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P3_LSB, 16);
dig_P4 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P4_LSB, 16);
dig_P5 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P5_LSB, 16);
dig_P6 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P6_LSB, 16);
dig_P7 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P7_LSB, 16);
dig_P8 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P8_LSB, 16);
dig_P9 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_P9_LSB, 16);
dig_H1 = (uint8) I2C_read_multiple_msb(_address, BME280_REG_DIG_H1_MSB, 8);
dig_H2 = (sint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_H2_LSB, 16);
dig_H3 = (uint8) I2C_read_multiple_msb(_address, BME280_REG_DIG_H3_MSB, 8);
dig_H4 = (sint16) I2C_read_multiple_msb(_address, BME280_REG_DIG_H4_MSB, 12);
// dig_H5 is a special case, see below
dig_H6 = (sint8) I2C_read_multiple_msb(_address, BME280_REG_DIG_H6_MSB, 8);
uint16 d_H5;
d_H5 = (uint16) I2C_read_multiple_lsb(_address, BME280_REG_DIG_H5_LSB, 12);
dig_H5 = (sint16) ((d_H5 << 4) & 0xFF0) | ((d_H5 >> 8) & 0xF);
}
uint8 BME280_initialized()
{
return _address != 0;
}
sint32 BME280_get_temperature_int32()
{
uint32 data;
sint32 adc_T;
data = I2C_read_multiple_msb(_address, BME280_REG_TEMP_MSB, 20);
#ifdef DEBUG
os_printf("\ndata: %u", data);
os_printf("\ndig_T1: %u", dig_T1);
os_printf("\ndig_T2: %d", dig_T2);
os_printf("\ndig_T3: %d", dig_T3);
#endif
adc_T = (sint32) data;
// Code from Datasheet, formatted by Eclipse
BME280_S32_t var1, var2;
var1 = ((((adc_T >> 3) - ((BME280_S32_t) dig_T1 << 1)))
* ((BME280_S32_t) dig_T2)) >> 11;
var2 = (((((adc_T >> 4) - ((BME280_S32_t) dig_T1))
* ((adc_T >> 4) - ((BME280_S32_t) dig_T1))) >> 12)
* ((BME280_S32_t) dig_T3)) >> 14;
t_fine = var1 + var2;
BME280_temp_sint = (t_fine * 5 + 128) >> 8;
return BME280_temp_sint;
}
uint32 BME280_get_pressure_int64()
{
uint32 data;
sint32 adc_P;
data = I2C_read_multiple_msb(_address, BME280_REG_PRESS_MSB, 20);
#ifdef DEBUG
os_printf("\ndata: %u", data);
os_printf("\ndig_P1: %u", dig_P1);
os_printf("\ndig_P2: %d", dig_P2);
os_printf("\ndig_P3: %d", dig_P3);
os_printf("\ndig_P4: %d", dig_P4);
os_printf("\ndig_P5: %d", dig_P5);
os_printf("\ndig_P6: %d", dig_P6);
os_printf("\ndig_P7: %d", dig_P7);
os_printf("\ndig_P8: %d", dig_P8);
os_printf("\ndig_P9: %d", dig_P9);
#endif
adc_P = (sint32) data;
// Code from Datasheet, formatted by Eclipse
BME280_S64_t var1, var2, p;
var1 = ((BME280_S64_t) t_fine) - 128000;
var2 = var1 * var1 * (BME280_S64_t) dig_P6;
var2 = var2 + ((var1 * (BME280_S64_t) dig_P5) << 17);
var2 = var2 + (((BME280_S64_t) dig_P4) << 35);
var1 = ((var1 * var1 * (BME280_S64_t) dig_P3) >> 8)
+ ((var1 * (BME280_S64_t) dig_P2) << 12);
var1 = (((((BME280_S64_t) 1) << 47) + var1)) * ((BME280_S64_t) dig_P1)
>> 33;
if (var1 == 0) {
return 0; // avoid exception caused by division by zero
}
p = 1048576 - adc_P;
p = (((p << 31) - var2) * 3125) / var1;
var1 = (((BME280_S64_t) dig_P9) * (p >> 13) * (p >> 13)) >> 25;
var2 = (((BME280_S64_t) dig_P8) * p) >> 19;
BME280_press_uint = (BME280_U32_t) ((p + var1 + var2) >> 8) + (((BME280_S64_t) dig_P7) << 4);
return BME280_press_uint;
}
uint32 BME280_get_humidity_int32()
{
uint32 data;
sint32 adc_H;
data = I2C_read_multiple_msb(_address, BME280_REG_HUM_MSB, 16);
#ifdef DEBUG
os_printf("\ndata: %u", data);
os_printf("\ndig_H1: %u", dig_H1);
os_printf("\ndig_H2: %d", dig_H2);
os_printf("\ndig_H3: %u", dig_H3);
#endif
adc_H = (sint32) data;
// Code from Datasheet, formatted by Eclipse
BME280_S32_t v_x1_u32r;
v_x1_u32r = (t_fine - ((BME280_S32_t) 76800));
v_x1_u32r =
(((((adc_H << 14) - (((BME280_S32_t) dig_H4) << 20)
- (((BME280_S32_t) dig_H5) * v_x1_u32r))
+ ((BME280_S32_t) 16384)) >> 15)
* (((((((v_x1_u32r * ((BME280_S32_t) dig_H6)) >> 10)
* (((v_x1_u32r * ((BME280_S32_t) dig_H3)) >> 11)
+ ((BME280_S32_t) 32768))) >> 10)
+ ((BME280_S32_t) 2097152))
* ((BME280_S32_t) dig_H2) + 8192) >> 14));
v_x1_u32r = (v_x1_u32r
- (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7)
* ((BME280_S32_t) dig_H1)) >> 4));
v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r);
v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r);
BME280_hum_uint = (BME280_U32_t) (v_x1_u32r >> 12);
return BME280_hum_uint;
}
double BME280_get_temperature_double()
{
uint32 data;
sint32 adc_T;
data = I2C_read_multiple_msb(_address, BME280_REG_TEMP_MSB, 20);
#ifdef DEBUG
os_printf("\ndata: %u", data);
os_printf("\ndig_T1: %u", dig_T1);
os_printf("\ndig_T2: %d", dig_T2);
os_printf("\ndig_T3: %d", dig_T3);
#endif
adc_T = (sint32) data;
// Code from Datasheet, formatted by Eclipse
double var1, var2, T;
var1 = (((double)adc_T)/16384.0 - ((double)dig_T1)/1024.0) * ((double)dig_T2);
var2 = ((((double)adc_T)/131072.0 - ((double)dig_T1)/8192.0) *
(((double)adc_T)/131072.0 - ((double) dig_T1)/8192.0)) * ((double)dig_T3);
t_fine = (BME280_S32_t)(var1 + var2);
T = (var1 + var2) / 5120.0;
return T;
}
double BME280_get_pressure_double()
{
uint32 data;
sint32 adc_P;
data = I2C_read_multiple_msb(_address, BME280_REG_PRESS_MSB, 20);
#ifdef DEBUG
os_printf("\ndata: %u", data);
os_printf("\ndig_P1: %u", dig_P1);
os_printf("\ndig_P2: %d", dig_P2);
os_printf("\ndig_P3: %d", dig_P3);
os_printf("\ndig_P4: %d", dig_P4);
os_printf("\ndig_P5: %d", dig_P5);
os_printf("\ndig_P6: %d", dig_P6);
os_printf("\ndig_P7: %d", dig_P7);
os_printf("\ndig_P8: %d", dig_P8);
os_printf("\ndig_P9: %d", dig_P9);
#endif
adc_P = (sint32) data;
// Code from Datasheet, formatted by Eclipse
double var1, var2, p;
var1 = ((double)t_fine/2.0) - 64000.0;
var2 = var1 * var1 * ((double)dig_P6) / 32768.0;
var2 = var2 + var1 * ((double)dig_P5) * 2.0;
var2 = (var2/4.0)+(((double)dig_P4) * 65536.0);
var1 = (((double)dig_P3) * var1 * var1 / 524288.0 + ((double)dig_P2) * var1) / 524288.0;
var1 = (1.0 + var1 / 32768.0)*((double)dig_P1);
if (var1 == 0.0)
{
return 0; // avoid exception caused by division by zero
}
p = 1048576.0 - (double)adc_P;
p = (p - (var2 / 4096.0)) * 6250.0 / var1;
var1 = ((double)dig_P9) * p * p / 2147483648.0;
var2 = p * ((double)dig_P8) / 32768.0;
p = p + (var1 + var2 + ((double)dig_P7)) / 16.0;
return p;
}
double BME280_get_humidity_double()
{
uint32 data;
sint32 adc_H;
data = I2C_read_multiple_msb(_address, BME280_REG_HUM_MSB, 20);
#ifdef DEBUG
os_printf("\ndata: %u", data);
os_printf("\ndig_H1: %u", dig_H1);
os_printf("\ndig_H2: %d", dig_H2);
os_printf("\ndig_H3: %u", dig_H3);
#endif
adc_H = (sint32) data;
// Code from Datasheet, formatted by Eclipse
double var_H;
var_H = (((double)t_fine) - 76800.0);
var_H = (adc_H - (((double)dig_H4) * 64.0 + ((double)dig_H5) / 16384.0 * var_H)) *
(((double)dig_H2) / 65536.0 * (1.0 + ((double)dig_H6) / 67108864.0 * var_H *
(1.0 + ((double)dig_H3) / 67108864.0 * var_H)));
var_H = var_H * (1.0 - ((double)dig_H1) * var_H / 524288.0);
if (var_H > 100.0)
var_H = 100.0;
else if (var_H < 0.0)
var_H = 0.0;
return var_H;
}