bmp280 datasheet

Bosch
Sensortec | BMP280 Data sheet
21 |
48
Modifications reserved | Data subject to change without notice
Document number: BST-BMP280-DS001-23 Revision_1.23_11202
0
Table 16: Computational requirements for compensation formulas
Compensation of Number of clock cycles (ARM Cortex-M3)
32 bit integer 64 bit integer Double precision
Temperature
~46
–
~2400
7
Pressure
~112
8
~1400
~5400 7
3.11.2 Trimming parameter readout
The trimming parameters are programmed into the devices’ non-volatile memory (NVM) during
production and cannot be altered by the customer. Each compensation word is a 16-bit signed or
unsigned integer value stored in two’s complement. As the memory is organized into 8-bit words, two
words must always be combined in order to represent the compensation word. The 8-bit registers are
named calib00…calib25 and are stored at memory addresses 0x88…0xA1. The corresponding
compensation words are named dig_T# for temperature compensation related values and dig_P# for
pressure compensation related values. The mapping is shown in Table 17.
Table 17: Compensation parameter storage, naming and data type
Register
Address
LSB / MSB
Register
content
Data type
0x88 / 0x89
dig_T1
unsigned short
0x8A / 0x8B
dig_T2
signed short
0x8C / 0x8D
dig_T3
signed short
0x8E / 0x8F
dig_P1
unsigned short
0x90 / 0x91
dig_P2
signed short
0x92 / 0x93
dig_P3
signed short
0x94 / 0x95
dig_P4
signed short
0x96 / 0x97 dig_P5 signed short
0x98 / 0x99
dig_P6
signed short
0x9A / 0x9B
dig_P7
signed short
0x9C / 0x9D
dig_P8
signed short
0x9E / 0x9F
dig_P9
signed short
0xA0 / 0xA1
reserved
reserved
3.11.3 Compensation formula
Please note that it is strongly advised to use the API available from Bosch Sensortec to perform
readout and compensation. If this is not wanted, the code below can be applied at the user’s risk. Both
pressure and temperature values are expected to be received in 20 bit format, positive, stored in a 32
bit signed integer.
7
Use only recommended for high-level programming languages like Matlab™ or LabVIEW™
8
Use only recommended for 8-bit micro controllers