Data Sheet

Bosch Sensortec | BME280 Data sheet
26 | 55
Modifications reserved | Data subject to change without notice
Document number: BST-BME280-DS002-15
Revision_1.6_092018
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);
return (BME280_U32_t)(v_x1_u32r>>12);
}
5. Global memory map and register description
5.1 General remarks
The entire communication with the device is performed by reading from and writing to registers.
Registers have a width of 8 bits. There are several registers which are reserved; they should not be
written to and no specific value is guaranteed when they are read. For details on the interface, consult
chapter 6.
5.2 Register compatibility to BMP280
The BME280 is downward register compatible to the BMP280, which means that the pressure and
temperature control and readout is identical to BMP280. However, the following exceptions have to be
considered:
Table 17: Register incompatibilities between BMP280 and BME280
Register
Bits
Content
BMP280
BME280
0xD0 “id”
7:0
chip_id
Read value is
0x56 / 0x57 (samples)
0x58 (mass production)
Read value is 0x60
0xF5 “config”
7:5
t_sb
‘110’: 2000 ms
‘111’: 4000 ms
‘110’: 10 ms
‘111’: 20 ms
0xF7…0xF9 “press”
19:0
press
Resolution (16…20 bit)
depends only on osrs_p
Without filter, resolution depends on
osrs_p; when using filter, resolution
is always 20 bit
0xFA…0xFC “temp”
19:0
temp
Resolution (16…20 bit)
only depends on osrs_t
Without filter, resolution depends on
osrs_t; when using filter, resolution is
always 20 bit
5.3 Memory map
The memory map is given in Table 18 below. Reserved registers are not shown.